Thanks, Richard - just about to replace an old Danfoss wireless thermostat with the Honeywell set and your wiring instructions were bang on! Brilliant, much appreciated, mate!
You beauty - used to connect 550W IR panel and round thermostat. Resideo help desk seemed more interested in avoiding any liability than offering guidance
Hi we have a Honeywell T3R programmable thermostat to a new Vaillant eco tec pro 28 boiler and we’ve wired it as we have always other boilers but it won’t work? Vaillant have suggested putting a link in like your video but it doesn’t work? Have got any suggestions please?
I’m confused about the live link wire because in the manual page 41 it has the link wire connecting the two lives and room stat wires (2 of) running to A and B for a permanent live combi. Whereas you’re linking a live to A.
The ‘A’ terminal is the ‘common’ connection terminal on the BDR91 and ‘B’ is the ‘normally open’ terminal. In electronic circuits if you attach any voltage to a relay, it is normally attached to the ‘common’ terminal, hence on the video a 230v feed wire has been attached to ‘A’ from the second ‘L’ terminal. Please note that the video illustrates a 230V switching circuit. If the boiler is extra low voltage switching, you wouldn’t use a link wire from the second ‘L’ terminal and the connections from the boiler would be directly to the ‘A’ and ‘B’ terminal.
@MWPHS Hi, I have recently purchased a new thermostat from your shop to upgrade my old Honeywell DT90 Thermostat. I have purchased the newer version of the Honeywell BDR91. In my old DT90 I had two wires. A brown wire that went into A (this is the electric wire as it had power) and a black wire that went into B (I assume this one was from the boiler?). And all worked well. How do I know connect the new relay of the BDR91. I tried different options but the reley just does not want to work and the two led lights are just not turning on. Maybe the relay is faulty? Any help would be much appreciated.
Just for clarity the BDR91 requires a minimum of 3 wires plus an earth. The BDR91 requires a Permanent Live and Neutral and the switching wire back to the boiler. Some thermostats have two wires (Live and Switched Live), which means the BDR91 won't work as you would be missing the Neutral.
@@MWPHSdo you know of any wireless receiver units with programmable sender, that will work without permanent live or neutral and just switched live and return? I’ve got an old wall thermo that just has black, blue with brown sheath and earth!
Isolate the mains voltage and then insert a large flat bladed screw driver into the slot at the base of the BDR91. This will release the catch which will allow the BDR91 to release from the base and swing open.
3 core and earth cable is required. If you only have twin and earth it won’t work. Thermostats using two cores are normally live and switched live, but you still should have a protective earth conductor? If in doubt contact a competent electrician.
It shouldn’t matter (as long as the blue wire isn’t the ‘Neutral’ of course!) but always good practice to put the voltage feed from the boiler to the ‘common’ terminal ‘A’ and switched feed back to the boiler on the ‘B’ terminal.
So for a no volt switched contacts. Leave out the live link and connect the A and B to the thermostat zero volt connector on the boiler. These contacts will open and close depending on the thermostat setting . Think this is right. Please confirm
Thanks, Richard - just about to replace an old Danfoss wireless thermostat with the Honeywell set and your wiring instructions were bang on! Brilliant, much appreciated, mate!
thank you for the explanation. Pity the instructions don't mention the link wire for 240 v
You beauty - used to connect 550W IR panel and round thermostat. Resideo help desk seemed more interested in avoiding any liability than offering guidance
No problem, glad my guidance helped! :)
I needed to do one more thing in order to make it work: add a bridge between the two L's. On my BDR91T they are not internally connected.
You do not need to bridge the two L's normally... As long as the BDR91 is not faulty, it will be linked on the PCB.
Hi we have a Honeywell T3R programmable thermostat to a new Vaillant eco tec pro 28 boiler and we’ve wired it as we have always other boilers but it won’t work? Vaillant have suggested putting a link in like your video but it doesn’t work? Have got any suggestions please?
Sorry I don't, as the T3R has a different wireless receiver to this one and I don't know enough about the Vaillant boiler to comment.
@@MWPHS thanks for replying anyway my mate - all the best 👍👍
Same problém With viessmann vitodens 111. Port 96 . Exact connections od Boiler and relaY. Attached unkversal Honeywell scheme dobe work … fail
I’m confused about the live link wire because in the manual page 41 it has the link wire connecting the two lives and room stat wires (2 of) running to A and B for a permanent live combi. Whereas you’re linking a live to A.
The ‘A’ terminal is the ‘common’ connection terminal on the BDR91 and ‘B’ is the ‘normally open’ terminal. In electronic circuits if you attach any voltage to a relay, it is normally attached to the ‘common’ terminal, hence on the video a 230v feed wire has been attached to ‘A’ from the second ‘L’ terminal. Please note that the video illustrates a 230V switching circuit. If the boiler is extra low voltage switching, you wouldn’t use a link wire from the second ‘L’ terminal and the connections from the boiler would be directly to the ‘A’ and ‘B’ terminal.
@MWPHS
Hi, I have recently purchased a new thermostat from your shop to upgrade my old Honeywell DT90 Thermostat. I have purchased the newer version of the Honeywell BDR91.
In my old DT90 I had two wires. A brown wire that went into A (this is the electric wire as it had power) and a black wire that went into B (I assume this one was from the boiler?). And all worked well.
How do I know connect the new relay of the BDR91. I tried different options but the reley just does not want to work and the two led lights are just not turning on.
Maybe the relay is faulty? Any help would be much appreciated.
Just for clarity the BDR91 requires a minimum of 3 wires plus an earth. The BDR91 requires a Permanent Live and Neutral and the switching wire back to the boiler. Some thermostats have two wires (Live and Switched Live), which means the BDR91 won't work as you would be missing the Neutral.
@@MWPHSdo you know of any wireless receiver units with programmable sender, that will work without permanent live or neutral and just switched live and return? I’ve got an old wall thermo that just has black, blue with brown sheath and earth!
Very informative
Brilliant thanks. That helped me get it right.
Glad it helped... If you haven't already, please like the video! :)
Could you let me know how to remove the cover please once it’s on the wall?
Isolate the mains voltage and then insert a large flat bladed screw driver into the slot at the base of the BDR91. This will release the catch which will allow the BDR91 to release from the base and swing open.
@@MWPHS fantastic!😃thank you👍🏼
Does it matter which way round the A and B are when you wire them to the "two low vaultage switching terminals" on the boiler?
If it’s low voltage switching, then it shouldn’t matter which way round A and B are.
If I am replacing a bimetallic thermostat with this and only have a live and neutral wire to the boiler, how should I wire it?
3 core and earth cable is required. If you only have twin and earth it won’t work. Thermostats using two cores are normally live and switched live, but you still should have a protective earth conductor? If in doubt contact a competent electrician.
Hellow sir....from boiler i put blue cable to A and brown cable to B,it is ok? Or doesnt matter
It shouldn’t matter (as long as the blue wire isn’t the ‘Neutral’ of course!) but always good practice to put the voltage feed from the boiler to the ‘common’ terminal ‘A’ and switched feed back to the boiler on the ‘B’ terminal.
If i got some wrong,what it can happend? If i inverse A with B?
So for a no volt switched contacts. Leave out the live link and connect the A and B to the thermostat zero volt connector on the boiler. These contacts will open and close depending on the thermostat setting . Think this is right. Please confirm
Yes you are correct. A & B are volt free contacts unless you physically put 230v onto them.