Thank you very much for posting this video. You not only help us in restoring the hot water and heating but saved us from paying for call out costs in this cost of living crisis. I have bought exact make and able to replace it myself.
Excellent - as a landlord I had a beleaguered tenant who needed hot water for her children’s bath time after the plumber had reset the boiler. This solution sorted it. You’re a gem
Simon, thank you for posting this problem with the ST9400C programmer and for the brilliant demonstration of how to replace it. I had exactly the same issue with mine after 11 years of use, and it was such a relief to see that it is a known problem and so easy to resolve. Credit also to Honeywell for designing the product in a way that allows an amateur to replace the main item while leaving the professionally installed backplate in situ. Very happy now.
I haven’t the same problem, my boiler and program unit were installed at the same time. My fault is that when I turn off the ST9400 power was still getting through to the boiler, which would fire up even when turned off. I’m going to get a new ST9400, now full of confidence that it’s easy to install. Kudos Simon.
I have been freezing for 2 months without heating as trying to decide if it was the rayburn or the programmer just to delay calling out the engineer (££££). Your video was great and within 5 minutes, I have heating. All by turning off the backlight! You have also given me the confidence to change the programmer. I'm 63 and dead chuffed. Thankyou. Linda.
Linda, you're not as chuffed as I am that I was able to help. Its a while ago now so I can't quite remember, but I think turning the light off only worked for a short while so it might need attention again soon. A neighbour told me he got the manufacturer to replace it because there was a known fault at one time, so might be worth dropping them a line now
Thanks Simon. Our fault was a bit different. I'd turned off the power to fix something else, turned it on again and the controller was unclearly dying: just a hint of a display, very faint, soon gone altogether! So thanks for the clue about the two little screws; so I soon had the unit off it's wallplate. And having read the instructions about how there's a battery in there that keeps the clock going, I thought maybe that's dead or not charging and maybe I can fix that? With nothing to lose, I was going in! If you turn the unit onto its face you can see four plastic flaps that hold the back on. I inserted a small flat screwdriver into the slot behind a flap and turned it, whilst pressing a thumbnail into a nearby part of the groove between front and back. Bingo! the flap lost its grip and the groove became a bit wider. One-by-one I defeated the flaps until the back lifted easily off, revealing the circuit board. And what did I see mounted upon it but an ordinary 2032 Lithium battery, just like I keep spares of for clocks and the like. It was a bit fiddly to get out of its holder - I eased back a thin metal catch very carefully not to harm it, until that side of the old battery could be lifted past it, then pulled away from the opposing plastic retaining ridges. I fitted the replacement into the metal catch first though, then snapped the other side down past those plastic ridges. The job looked a good 'un, so I snapped the back on again and refitted the unit to it's wallplate. With bated breath I turned on the power and... (Bingo again) the display lit up! All I had to do was reset the date (the program, apparently, is stored in some non-volatile kind of memory) and the unit promptly resumed normal duties. The job WAS a good 'un! Maybe my unit is faulty nevertheless, in some battery-draining kind of way, and my triumph will be short-lived. But for now I'm wondering how many of these controllers have gone into landfill for the want of a cheap little battery!
Thank you. Even though the controller was wired to the wall, this video gave me the confidence to remove it and look inside. I saw there was a 2032 lithium battery disc which I swapped for a spare that I had to hand and hey presto! An enormous feeling of empowerment and satisfaction, thank you so much!
Sinon! What a guy! This has just solved our problem too and I now look like a genius to my boyfriend. I did tell him I’d watched this video so I gave you full credit. But you saved us a weekend call out fee and an additional £300 on a new panel they wanted to install, so thank you!
I noticed my ST9100 would not work in override mode but was working in program mode. Did the backlight off trick and now it is working in all modes. Great . Thank you for taking time to document this.
Honeywell/Resideo would not send me a free replacement, even though mine was in the so called recall batch. Fair enough it is 11 years old. I replaced the main power cap (0.68uF, 275V) and it now works with backlight on. Thanks again.
What a bloke! My programmer was shutting of when trying to put water on at same time as heating. Turned back light of and we are good to go again !! Cheers
Glad to hear it! Was a while ago now, but mine worked ok like that for a bit but then continued to get worse, so I'd keep in mind that you might yet need to change it
Many many thanks for your video Simon. Mine failed today and followed your video to check and replace it. Took the option in the Installer menu to set the backlight to 'on when worked' which I'm hoping prolongs the life of my new unit. Thanks again.
Thanks very much. I had the same problem with a unit purchased in 2010. I thought my wiring was the problem until I found your video. Just purchased a replacement unit (Oct 2017) from Screw Fix for £70 and all sorted. Easy to replace. Replacement unit fitted onto existing backplate. Only slight niggle is the new unit has an updated screen which is hopeless when viewed side on - this applies to my installation. If I really want to read the screen now I have to stick my head in the airing cupboard! (or move the backplate I guess...)
Wanted to say a huge thank you. This video has just sorted the very same problems for me, and I feel confident enough as a result to change the unit over. We live in a rented property with a very particular Landlord....at a time with Covid, when I really don't want unnecessary people in my home this video was a godsend. Thank you.
You super star sir!! Ok, so confident that this is the same problem, but what no other video I found showed, was how easy it is to replace, just switch the unit over, and leave the back plate, 10 minutes job! Thanks for the heads up!
Thanks! Just found this and what you've shown is exactly what mine is doing as no heating or hot water this morning (cold showers - brrrrrr!) and this was clicking on and off! So off to the "fixer of screws" shop this morning to pick up one to replace with. Was nearly about to call an engineers in .
@@sxt20002000 easy slot in replacement that was slightly hampered by me not cutting the tabs out for the power cable first otherwise would have been 30 seconds!
I have exactly this fault right now - I found some "pigeon english" instructions on how to access the installer mode and turn off the backlight elsewhere but couldn't follow these - your instructions are crystal clear. Also, thanks for explaining how easy it is to replace the unit and for the tip about staggering the heating and water times. Great work :)
Excellent. Saved me a lot of money in a: temporarily solving the problem and b: sorting out the replacement. Proof social media’s not all bad. Thank you.
Your an absolute superstar for posting this, it's just before Xmas and my controller had the same issue and getting zero heat, cant believe turning off the backlight got it working again...tahnks.
A useful post that highlights that also highlights how the ST9420C can be a bit tricksy. I had problems binding a new DTS92E thermostat - followed he instructions to the letter and cleared the old thermostat but it just woudn't bind to the new one. Solution - don't just clear it but power down the ST9420 programmer completely for 30 seconds by switching off - then switch it on and go to the binding menu - worked first time then! The rule is: always factor in switching it off and switching it on again.....
Thank you so much for this video. It's winter and snowing and I've managed to get my boiler back on! A replacement unit isn't going to break the bank too much either. Legend.
Great fix Simon. I have an almost identical problem on my controller that I diagnosed instantly when I watched your video. I spotted that the backlight was dimming when the internal relays were trying to switch on and I couldn't get both water and heating at the same time. Basically what is happening is that the internal power supply mains dropper capacitor has degraded over the years and can no longer supply enough current for the unit to work properly. It's a 30p part if you have basic electronic skills and can dismantle the unit. I'll probably buy a new one and fix the old one for spare.
UK Covid-19 Lockdown day 7. I started coughing 2 days ago so daughters and me are now in full quarantine. This morning it snowed and hailed and the heating wouldn't come on so the house was freezing. 0 degrees also forecast for tonight. Thanks to you I've fixed it cost free, we're all warm and it's one problem we don't have. Very grateful that you shared this solution ! I've ordered a replacement and am hoping I'll be able to install new one myself if it goes wrong again.
Great Video. Thank you. Our boiler wouldn't turn off and as I had this unit because of a previous fault I fitted it as a first step. Just a small point. Our unit was mounted on a solid wall and the replacement unit wouldn't close properly. It took a while to realise that because the connecting wires came out of the front I had to 'nibble' at the wire entry points to make holes with a pair of pliers. There are lines cut in the unit if you need to do this.
Thank you Simon for taking the time to fully explain. Would be interesting to know if the backplate is compatible with any other brands. If so then, perhaps we might be able to easily swap Honeywell controller for another (cheaper!) type. I realise that changing the backplate is not a big job, but it really should be done by a competent electrician. Excellent post.
Thanks for the video Simon, this is exactly the same fault as mine developed this week. I rang Honeywell today and after providing them with pretty minimal information, they are sending out a replacment FOC, so very happy with that. A bit more research showed that it is a faulty capacitor that is the problem. I've ordered what I think is the right one and will fit it to see whether that does indeed cure the fault. I can then keep the old programmer as a spare.
Hi Matt, could you let me know the type of the capacitor that you brought? I have the same problem on a ST9100C. I already provide information to Honeywell for a free replacement. However, I still want to repair the old one if it is not too difficult.
Unfortunately either I bought the wrong capacitor or my repair didn't work as the fault was still present. However, Honeywell were very good in getting a new item to me which has worked perfectly so far.
Thanks so much for this Simon. We have just bought a house with one of this fitted. My problem is setting the daily programmer … I have the manual … I set the 6 times, press ok and it always defaults to Monday which isn’t a concern. However no amount of button pushing on ‘next day ‘ or ‘copy’ does anything. In effect we don’t have a program for the next 6 days. I’d like to fix it but it’s good to know I can replace it … thanks to you.
Thank you again! I now replaced with new ST9400C & You are right- when you can do it that means I and even others can also do it. So nicely explained. Thanks.
Thanks for this Simon - extremely helpful, and has sorted the fault as a temporary fix, and I'll give it a go to replace the unit, as I was planning to get someone out to do it for me, but it does look straight forward, so you've convinced me to do it myself! Thanks again.
Hi,I had the same fault with st9100c,your video help me,it ‘fixed’ the fault,I will order a replacement unit.Thanks very much👍👍👍👍👍👍👍👍👍👍👍👍👍👍👍👍👍👍👍👍👍👍👍👍👍👍👍👍👍
Happy to have been able to help. From memory (it's 3 years or so ago) the fix of turning the backlight off didn't last for long. Fingers crossed for you though
Please note Honeywell produced a faulty batch of these programmers back in 2010.If you have a faulty one Honeywell will replace the unit free of charge.The batch numbers are between 1037 - 1139.The numbers can be found inside the unit once removed from the back plate.
Hi, I just tried to contact Honeywell customer support about a problem with the same unit fitted in 2010 and they sent me to a page to talk to a technician at a cost of £5 Do you have a link where you contacted, thanks for any help you can give. Terry.
This was great information to know, thank you for posting this comment. I had a faulty programmer that fell within the batch numbers you stated. Spoke to Honeywell customer services who just advised me to just go ahead and purchase a replacement unit. I then went back to them saying that I had read online that they had produced a batch of faulty programmers between the batch numbers of 1037 - 1139 and mine was within this batch. To which they replied that they will send out a replacement unit to me completely free of charge! Thanks to this comment, I’ve managed to save myself a few quid! Much appreciated.
Cheers, just managed to get our heating on by turning the back light off. Now I know it's only the controller I'll get a new one and not get someone out for the boiler.
I'm havng trouble with the hot water overide switch which doesn't seem to work when heating is set to "on" even if heating not required. I set heating to "off" and then change hot water to permanently "on". This seems work but is annoying. The unit is about 9 years old so I guess time for a new one. Thanks for the video.
thank you Simon for the video to show me that i could replace the unit myself despite that it was 6 years ago . My apt has the same unit to control the boiler, however I'm not sure when the mode switch button on the heating side stopped working. Now I can't change the heating to auto, once or cont modes... but the hot water side works. Do you think replacing the st9400c unit will solve the problem? because it seems that only one button isnt working... so i am wondering if there 's another problem causing it.
Thank you ! Mine has just started doing this, did Honeywell not offer a firmware or replacement foc? I may try that first if not then I'll pick up a new one. * edit: ok contacted Honeywell, gave the details, they emailed me for some info and they are sending a replacement FOC. :)
Glad to hear you got it sorted FOC. With mine the timings were such that when it finally packed up I needed to get it changed *immediately*, so no time to try them. And to be honest, the age of it was such I didn't really think of trying Honeywell - might give them a try now though ;-)
Hi Simon, experiencing the same problem.I have bought a replacement, do I need to take the backplate of the old one and replace the new one entirely please ?
Hi, I just swapped the unit and not the backplate. It doesn't *quite* fit, so the screen sometimes doesn't display correctly. Works perfectly though, and the display works properly if you gently push it onto the back plate. That might bother some people but we never got round to sorting it
What does your wiring to the backplate look like? Looking at general google question/answer, it is normal for the boiler to fire up even when neither hot water or heating is on but after about 4 years and managing to sort out a configuration for the wiring, we can leave the programmer on instead of manually turning on/off. Primary wiring is ok using live/neutral/earth but the wiring from the thermostat is strange using a brown/black/grey colour wires
No idea. Didn't go anywhere near the wiring - didn't need to and wouldn't know how. The heating system has behaved itself perfectly since I changed the unit
Hi, we have the ST9400C next to the boiler and in our house the CM927 thermostat. The water heating seems to work fine … the heating this year we are having a slight issue. The heating comes on at the right time and the radiators all warm up - but when the thermostat reaches the correct temperature the radiators do not switch off. I have checked the pairing between the CM927 and the little box (HC60NG Relay Box) on the wall beneath the ST9400C and they seem to be paired OK. The flame does go off of the main thermostat when the heat reaches the desired temperature and also the green light on the small unit goes off. But the radiators seem to just stay on … where as before the radiators used to switch off at the desired heat. Any advice would be greatly appreciated.
Hi, it meant that the boiler for the heating was switching on and off. So it would come on, but shortly afterwards going through the power down procedure before coming back on again, and so on and so on.... It did generate some heating, but less than normal
Hi Simon my unit fault is the hot water and heating lights flashing noisily on an alternate pattern I phoned Honeywell and they did not offer a replacement I asked if they were faulty but it was a tough you need to replace it attitude, any ideas cheers
Hi simon a couple of years ago this solution worked by switching the light off. 2 years on and the panel is switching on and off again. I tried putting light back on and see if it would stop the flickering but no use. I guess i need to but a new panel unless you have another solution?
Hi Simon I bought a new one today from wickes. Just one question. You mentioned the panel comes with two pieces and that the old electric piece in the back was wired to the wall. Can I just unscrew the face of the old panel and put the new face onto the old electric back bit already wired in?
@@jaysea32 Bear in mind that (1) it was 7 years or so ago and (2) I'm no electrician so I can't advise I can only say what I did, but I think that's it. The new panel doesn't quite sit flush on the old casing so the display sometimes needs to be gently pushed on to the housing to show the time etc, but it functionally works.
thanks, backlight off and it worked, great temporary fix :-) Update - instead buy a new unit, I managed to repair it by adding a capacitor ruclips.net/video/tM4P39KxtyM/видео.html (the small capacitor)
Thank you very much for posting this video. You not only help us in restoring the hot water and heating but saved us from paying for call out costs in this cost of living crisis. I have bought exact make and able to replace it myself.
That's great to hear, pleased to have been able to help
Thank you for posting this video. Who would have thought that turning off the backlight would overcome the on/off cycle fault!
Excellent - as a landlord I had a beleaguered tenant who needed hot water for her children’s bath time after the plumber had reset the boiler. This solution sorted it. You’re a gem
That's great to hear, thank you
Simon, thank you for posting this problem with the ST9400C programmer and for the brilliant demonstration of how to replace it. I had exactly the same issue with mine after 11 years of use, and it was such a relief to see that it is a known problem and so easy to resolve. Credit also to Honeywell for designing the product in a way that allows an amateur to replace the main item while leaving the professionally installed backplate in situ. Very happy now.
I haven’t the same problem, my boiler and program unit were installed at the same time. My fault is that when I turn off the ST9400 power was still getting through to the boiler, which would fire up even when turned off. I’m going to get a new ST9400, now full of confidence that it’s easy to install. Kudos Simon.
I have been freezing for 2 months without heating as trying to decide if it was the rayburn or the programmer just to delay calling out the engineer (££££). Your video was great and within 5 minutes, I have heating. All by turning off the backlight! You have also given me the confidence to change the programmer. I'm 63 and dead chuffed. Thankyou. Linda.
Linda, you're not as chuffed as I am that I was able to help.
Its a while ago now so I can't quite remember, but I think turning the light off only worked for a short while so it might need attention again soon.
A neighbour told me he got the manufacturer to replace it because there was a known fault at one time, so might be worth dropping them a line now
Thanks Simon. Our fault was a bit different. I'd turned off the power to fix something else, turned it on again and the controller was unclearly dying: just a hint of a display, very faint, soon gone altogether! So thanks for the clue about the two little screws; so I soon had the unit off it's wallplate. And having read the instructions about how there's a battery in there that keeps the clock going, I thought maybe that's dead or not charging and maybe I can fix that? With nothing to lose, I was going in!
If you turn the unit onto its face you can see four plastic flaps that hold the back on. I inserted a small flat screwdriver into the slot behind a flap and turned it, whilst pressing a thumbnail into a nearby part of the groove between front and back. Bingo! the flap lost its grip and the groove became a bit wider. One-by-one I defeated the flaps until the back lifted easily off, revealing the circuit board. And what did I see mounted upon it but an ordinary 2032 Lithium battery, just like I keep spares of for clocks and the like. It was a bit fiddly to get out of its holder - I eased back a thin metal catch very carefully not to harm it, until that side of the old battery could be lifted past it, then pulled away from the opposing plastic retaining ridges. I fitted the replacement into the metal catch first though, then snapped the other side down past those plastic ridges.
The job looked a good 'un, so I snapped the back on again and refitted the unit to it's wallplate. With bated breath I turned on the power and... (Bingo again) the display lit up! All I had to do was reset the date (the program, apparently, is stored in some non-volatile kind of memory) and the unit promptly resumed normal duties. The job WAS a good 'un!
Maybe my unit is faulty nevertheless, in some battery-draining kind of way, and my triumph will be short-lived. But for now I'm wondering how many of these controllers have gone into landfill for the want of a cheap little battery!
Thank you. Even though the controller was wired to the wall, this video gave me the confidence to remove it and look inside. I saw there was a 2032 lithium battery disc which I swapped for a spare that I had to hand and hey presto! An enormous feeling of empowerment and satisfaction, thank you so much!
That's kind of you to say, thank you. Glad you got it sorted
Sinon! What a guy! This has just solved our problem too and I now look like a genius to my boyfriend. I did tell him I’d watched this video so I gave you full credit. But you saved us a weekend call out fee and an additional £300 on a new panel they wanted to install, so thank you!
Thanks for this just saved me a call out fee. Mine stopped working so emboldened by your video I bought a new one and replaced. Simple.
I noticed my ST9100 would not work in override mode but was working in program mode. Did the backlight off trick and now it is working in all modes. Great . Thank you for taking time to document this.
Honeywell/Resideo would not send me a free replacement, even though mine was in the so called recall batch. Fair enough it is 11 years old. I replaced the main power cap (0.68uF, 275V) and it now works with backlight on. Thanks again.
What a bloke! My programmer was shutting of when trying to put water on at same time as heating. Turned back light of and we are good to go again !! Cheers
Glad to hear it!
Was a while ago now, but mine worked ok like that for a bit but then continued to get worse, so I'd keep in mind that you might yet need to change it
Many many thanks for your video Simon. Mine failed today and followed your video to check and replace it. Took the option in the Installer menu to set the backlight to 'on when worked' which I'm hoping prolongs the life of my new unit. Thanks again.
Thanks very much. I had the same problem with a unit purchased in 2010. I thought my wiring was the problem until I found your video. Just purchased a replacement unit (Oct 2017) from Screw Fix for £70 and all sorted. Easy to replace. Replacement unit fitted onto existing backplate. Only slight niggle is the new unit has an updated screen which is hopeless when viewed side on - this applies to my installation. If I really want to read the screen now I have to stick my head in the airing cupboard! (or move the backplate I guess...)
Wanted to say a huge thank you. This video has just sorted the very same problems for me, and I feel confident enough as a result to change the unit over. We live in a rented property with a very particular Landlord....at a time with Covid, when I really don't want unnecessary people in my home this video was a godsend. Thank you.
Pleased to hear it - glad to have been able to help
You super star sir!! Ok, so confident that this is the same problem, but what no other video I found showed, was how easy it is to replace, just switch the unit over, and leave the back plate, 10 minutes job! Thanks for the heads up!
Thanks! Just found this and what you've shown is exactly what mine is doing as no heating or hot water this morning (cold showers - brrrrrr!) and this was clicking on and off! So off to the "fixer of screws" shop this morning to pick up one to replace with. Was nearly about to call an engineers in .
Great, that's good to hear
@@sxt20002000 easy slot in replacement that was slightly hampered by me not cutting the tabs out for the power cable first otherwise would have been 30 seconds!
Thank god I found this, I was about to call a professional! I switched off the backlight and bingo! The thermostat came on! Thank you!
Happy to have helped Andy. Word of warning: that only worked for so long and then started being faulty again
I have exactly this fault right now - I found some "pigeon english" instructions on how to access the installer mode and turn off the backlight elsewhere but couldn't follow these - your instructions are crystal clear. Also, thanks for explaining how easy it is to replace the unit and for the tip about staggering the heating and water times. Great work :)
Mike Clarke Thanks for the feedback, glad to have been able to help
Excellent. Saved me a lot of money in a: temporarily solving the problem and b: sorting out the replacement. Proof social media’s not all bad. Thank you.
Your an absolute superstar for posting this, it's just before Xmas and my controller had the same issue and getting zero heat, cant believe turning off the backlight got it working again...tahnks.
Thanks, that's great to hear. It only works for so long so I would plan on getting it changed shortly, but that should keep you going for Christmas
Amazing! Thank you so much for posting. The switching off backlight trick worked straightaway to get our hot water back on!!
Great, pleased to hear it!
Thanks you so much for sharing its been extremely helpful. You saved me a huge gas Engineers’s bill.
A useful post that highlights that also highlights how the ST9420C can be a bit tricksy. I had problems binding a new DTS92E thermostat - followed he instructions to the letter and cleared the old thermostat but it just woudn't bind to the new one. Solution - don't just clear it but power down the ST9420 programmer completely for 30 seconds by switching off - then switch it on and go to the binding menu - worked first time then! The rule is: always factor in switching it off and switching it on again.....
Thanks for this video, kept our heating going over Christmas.
Happy to have been able to help
Thank you so much for this video. It's winter and snowing and I've managed to get my boiler back on! A replacement unit isn't going to break the bank too much either. Legend.
That's great to hear, hope you get it sorted
Hot water was working, Heating wasnt. Followed the "RESET" and now heating is working. Happy days. Thank you.
Thanks Simon, liked the temporary fix worked a treat. Had to buy a new unit and followed your instructions. It was straight forward as you said.
Yep! Well done - great video. Like others can't belive that turning the back-light off worked.
Many thanks, worked a treat. Same issues as well with hot water and heating causing this switching on and off.
Slim, QUIET, works great. I wanted modern and out of the way. This is it!
Can't believe turning the back light off could solve the problem!!! Thank you
Great fix Simon. I have an almost identical problem on my controller that I diagnosed instantly when I watched your video. I spotted that the backlight was dimming when the internal relays were trying to switch on and I couldn't get both water and heating at the same time. Basically what is happening is that the internal power supply mains dropper capacitor has degraded over the years and can no longer supply enough current for the unit to work properly. It's a 30p part if you have basic electronic skills and can dismantle the unit. I'll probably buy a new one and fix the old one for spare.
Fantastic! Your video kept us warm until the replacement arrived - thanks for taking the time to upload this!
Thanks for this. I will give it a go. I am guessing it will be the main big capacitor (not the electrolytic one).
UK Covid-19 Lockdown day 7. I started coughing 2 days ago so daughters and me are now in full quarantine. This morning it snowed and hailed and the heating wouldn't come on so the house was freezing. 0 degrees also forecast for tonight. Thanks to you I've fixed it cost free, we're all warm and it's one problem we don't have. Very grateful that you shared this solution ! I've ordered a replacement and am hoping I'll be able to install new one myself if it goes wrong again.
That's great, pleased to gave been able to help at this difficult time
Feeling fine now BTW, false alarm 🙂
Great help and switching the backlight off got me going again over the weekend
Thanks for really helpful video, my Honeywell 9100A started to go on and off when the heating was running and this has helped very much!
Great Video. Thank you. Our boiler wouldn't turn off and as I had this unit because of a previous fault I fitted it as a first step. Just a small point. Our unit was mounted on a solid wall and the replacement unit wouldn't close properly. It took a while to realise that because the connecting wires came out of the front I had to 'nibble' at the wire entry points to make holes with a pair of pliers. There are lines cut in the unit if you need to do this.
Thank you Simon for taking the time to fully explain. Would be interesting to know if the backplate is compatible with any other brands. If so then, perhaps we might be able to easily swap Honeywell controller for another (cheaper!) type. I realise that changing the backplate is not a big job, but it really should be done by a competent electrician. Excellent post.
Thanks for this video, I followed it for an ST9400S and it worked for me
Thanks, pleased to hear it
Thanks for the video Simon, this is exactly the same fault as mine developed this week. I rang Honeywell today and after providing them with pretty minimal information, they are sending out a replacment FOC, so very happy with that. A bit more research showed that it is a faulty capacitor that is the problem. I've ordered what I think is the right one and will fit it to see whether that does indeed cure the fault. I can then keep the old programmer as a spare.
Hi Matt, could you let me know the type of the capacitor that you brought? I have the same problem on a ST9100C. I already provide information to Honeywell for a free replacement. However, I still want to repair the old one if it is not too difficult.
Unfortunately either I bought the wrong capacitor or my repair didn't work as the fault was still present. However, Honeywell were very good in getting a new item to me which has worked perfectly so far.
+Matt Summerfield Thanks to let me know. I also received a replacement unit from Honeywell. It works fine.
Legend, spent all evening trying to fix and found this clip late at night. Tried the backlight trick and bob's ur uncle!! Thanks!
Thanks so much for this Simon. We have just bought a house with one of this fitted. My problem is setting the daily programmer … I have the manual … I set the 6 times, press ok and it always defaults to Monday which isn’t a concern. However no amount of button pushing on ‘next day ‘ or ‘copy’ does anything. In effect we don’t have a program for the next 6 days. I’d like to fix it but it’s good to know I can replace it … thanks to you.
Best how-to video I've seen - thank you - very useful
Thanks, another person saved from no hot water by your video.
Cool. The temporary fix worked for me. I have now ordered new device. Thank you👍🏻
Thank you again! I now replaced with new ST9400C & You are right- when you can do it that means I and even others can also do it. So nicely explained. Thanks.
Thanks Simon i did have the same fault, soon rectified once i had found your upload .new unit on order............
Thanks, Simon. Very clear and helpful.
Thanks Gordon, happy to have been able to have helped
Excellent and very helpful video, the temporary fix of the back light has worked for me I have one on order. Thank you
Thank you Simon, I was able to sort it out following your tips. You’re a super star!
Thank you, I'm happy to have been able to help
Thanks for this Simon - extremely helpful, and has sorted the fault as a temporary fix, and I'll give it a go to replace the unit, as I was planning to get someone out to do it for me, but it does look straight forward, so you've convinced me to do it myself! Thanks again.
Very helpful. Just fitted replacement unit without any difficulty.
Thank you Simon, solved the problem for now. Cheers Rob
Thanks Simon, mine has just died and your simple explanation of fitting replacement perfect :)
Hi,I had the same fault with st9100c,your video help me,it ‘fixed’ the fault,I will order a replacement unit.Thanks very much👍👍👍👍👍👍👍👍👍👍👍👍👍👍👍👍👍👍👍👍👍👍👍👍👍👍👍👍👍
Great stuff! Temporary fix has worked for me and ordering a new one as we speak 👍
Same fault on our ST9100C switched off backlight and it's OK, ordered replacement.
Thank you for posting this video Simon, it is of great help and is much appreciated!
Thanks for sharing this. Very useful stuff and the comments are grate too. Just getting my replacement now. Cheers!
Thank you Simon had this exact issue and turning off the backlight seemed to work. Will use it until it fully dies and will then buy a new one.
Happy to have been able to help. From memory (it's 3 years or so ago) the fix of turning the backlight off didn't last for long. Fingers crossed for you though
You’re an absolute life saver. Thanks a bunch for posting this.
You are very welcome, glad to have been able to help
Thank you sir! Got me running again (for now)
Please note Honeywell produced a faulty batch of these programmers back in 2010.If you have a faulty one Honeywell will replace the unit free of charge.The batch numbers are between 1037 - 1139.The numbers can be found inside the unit once removed from the back plate.
Thanks for the info - my faulty unit was 1040 so I have emailed Honeywell customer services for a replacement - hopefully FOC
Hi, I just tried to contact Honeywell customer support about a problem with the same unit fitted in 2010 and they sent me to a page to talk to a technician at a cost of £5
Do you have a link where you contacted, thanks for any help you can give. Terry.
Honeywell after a bit of tooing and froing are sending me a FOC replacement 🤗
Now received my FOC programmer and all working - a final thank you
This was great information to know, thank you for posting this comment.
I had a faulty programmer that fell within the batch numbers you stated.
Spoke to Honeywell customer services who just advised me to just go ahead and purchase a replacement unit. I then went back to them saying that I had read online that they had produced a batch of faulty programmers between the batch numbers of 1037 - 1139 and mine was within this batch. To which they replied that they will send out a replacement unit to me completely free of charge!
Thanks to this comment, I’ve managed to save myself a few quid! Much appreciated.
Thank you so much, back-light off and new one on order 👍
Thank u mine was doing the same took back light off figures crossed until I can replace the control
Great help, saved me getting someone out to fix. Thankyou for posting this.
Cheers, just managed to get our heating on by turning the back light off. Now I know it's only the controller I'll get a new one and not get someone out for the boiler.
Great stuff - not the weather to be without a boiler!
Thank you, really helpful - had exactly same problems !
I'm havng trouble with the hot water overide switch which doesn't seem to work when heating is set to "on" even if heating not required. I set heating to "off" and then change hot water to permanently "on". This seems work but is annoying. The unit is about 9 years old so I guess time for a new one. Thanks for the video.
thank you Simon for the video to show me that i could replace the unit myself despite that it was 6 years ago . My apt has the same unit to control the boiler, however I'm not sure when the mode switch button on the heating side stopped working. Now I can't change the heating to auto, once or cont modes... but the hot water side works. Do you think replacing the st9400c unit will solve the problem? because it seems that only one button isnt working... so i am wondering if there 's another problem causing it.
Excellent ! Problem solved thanks for that
Pleased to have been able to help
Fab temp fix. Clicking was driving me crazy 🙄 as was in hall. Silence is golden.
not sure how or why but this seems to of fixed mine for today 👍
Great help, many thanks!
Very helpful thank you
Thank you ! Mine has just started doing this, did Honeywell not offer a firmware or replacement foc? I may try that first if not then I'll pick up a new one. * edit: ok contacted Honeywell, gave the details, they emailed me for some info and they are sending a replacement FOC. :)
Glad to hear you got it sorted FOC. With mine the timings were such that when it finally packed up I needed to get it changed *immediately*, so no time to try them. And to be honest, the age of it was such I didn't really think of trying Honeywell - might give them a try now though ;-)
It worked! Thanks!
Great fix cheers mate I know it's temporary but thanks anyway
Hi Simon, experiencing the same problem.I have bought a replacement, do I need to take the backplate of the old one and replace the new one entirely please ?
Hi, I just swapped the unit and not the backplate. It doesn't *quite* fit, so the screen sometimes doesn't display correctly. Works perfectly though, and the display works properly if you gently push it onto the back plate. That might bother some people but we never got round to sorting it
What does your wiring to the backplate look like? Looking at general google question/answer, it is normal for the boiler to fire up even when neither hot water or heating is on but after about 4 years and managing to sort out a configuration for the wiring, we can leave the programmer on instead of manually turning on/off. Primary wiring is ok using live/neutral/earth but the wiring from the thermostat is strange using a brown/black/grey colour wires
No idea. Didn't go anywhere near the wiring - didn't need to and wouldn't know how. The heating system has behaved itself perfectly since I changed the unit
Turned the backlight off, unfortunately didn't stop it rebooting constantly. Thanks for the video though
Desperate for a bath, turning the the backlight off somehow works....? Thank you.
helped me! thank you!
Hi, we have the ST9400C next to the boiler and in our house the CM927 thermostat.
The water heating seems to work fine … the heating this year we are having a slight issue. The heating comes on at the right time and the radiators all warm up - but when the thermostat reaches the correct temperature the radiators do not switch off.
I have checked the pairing between the CM927 and the little box (HC60NG Relay Box) on the wall beneath the ST9400C and they seem to be paired OK. The flame does go off of the main thermostat when the heat reaches the desired temperature and also the green light on the small unit goes off. But the radiators seem to just stay on … where as before the radiators used to switch off at the desired heat.
Any advice would be greatly appreciated.
Sorry, I've only just seen your comment. Can't help with that I'm afraid. Hope you get it sorted out
Thank you so much !!!
Hi; when you had the fault did it affect your heating in general ?
Hi, it meant that the boiler for the heating was switching on and off. So it would come on, but shortly afterwards going through the power down procedure before coming back on again, and so on and so on.... It did generate some heating, but less than normal
Hi Simon my unit fault is the hot water and heating lights flashing noisily on an alternate pattern I phoned Honeywell and they did not offer a replacement I asked if they were faulty but it was a tough you need to replace it attitude, any ideas cheers
Hi, can't help with that - sorry. I just replaced mine
Hi simon a couple of years ago this solution worked by switching the light off.
2 years on and the panel is switching on and off again.
I tried putting light back on and see if it would stop the flickering but no use.
I guess i need to but a new panel unless you have another solution?
@@jaysea32 Only what's in the video, I'm afraid
Hi Simon I bought a new one today from wickes.
Just one question.
You mentioned the panel comes with two pieces and that the old electric piece in the back was wired to the wall.
Can I just unscrew the face of the old panel and put the new face onto the old electric back bit already wired in?
@@jaysea32 Bear in mind that (1) it was 7 years or so ago and (2) I'm no electrician so I can't advise I can only say what I did, but I think that's it. The new panel doesn't quite sit flush on the old casing so the display sometimes needs to be gently pushed on to the housing to show the time etc, but it functionally works.
@@sxt20002000 thanks.
Just one more I will bother you.
Did you have the panel switched off when you fitted it?
Thanks,you have been a great help.
Omg amazing!
It didn't fix it but it certainly stays on longer. I'll order a replacement. Was absolutely dreading I needed a new boiler
I was cleaning mine when it just suddenly turned off all it shows is wrong time and date I can't get it to turn back on can u help plz
Can you tell me please if there is any battery inside to replace?
@@rosprite1 No, it takes its power from the mains electricity
Thank you!!
Hi Simon do u know how to get in to the installer mode for a service plus s17r programmer
No idea, sorry!
I can't get mine to work on auto mode for zone 2, but zone 1 works fine.
How do I reset Service Due?
unfortunately didn't fix my unit by turning the backlight off... off to screwfix I go as its about 1degrees today..
thanks
thanks, backlight off and it worked, great temporary fix :-) Update - instead buy a new unit, I managed to repair it by adding a capacitor ruclips.net/video/tM4P39KxtyM/видео.html (the small capacitor)
If you're good at electronics here's a fix: ruclips.net/video/tM4P39KxtyM/видео.html
You don't say what's wrong with it and lots of mumbling.