Sir thank you. An Hvac tech was here 2 days ago and I asked him is there something in settings I am missing. He told me everything looks fine. Stumbled across your video and sure enough the cycle was set to 6. I turned it down to 2. Hopefully this will fix the ridiculous light bill. Thank you
grayfurnaceman Today was a day I came across an oversized system. ~100,000 btu of heat output in a space that needs only 50,000 btu. Space was split in two. All of the ducts are in the new (1/2 sized space). When heat comes on the space is heated quickly and overshoots the set point. When heat cycles off, it stays warm long enough. Everyone there is very UNCOMFORTABLE What would be a good cycle per hour setting ?
Did I misunderstand something? If furnace is oversized, holds and maintains temp, people are uncomfortable, why would you increase cph instead of decrease? I must of missed something.
FYI the car analogy you made is actually incorrect. Road & Track had an article in the December 2000 issue that showed rapid acceleration was significantly more efficient than slow acceleration and cruise. I know it seems counterintuitive. What Im wondering is what the algorithm looks like for the thermostat to cycle a set number of times per hour.
It is not only counterintuitive but it is wrong. I would love to look at the magazine but I could not find it on the internet. Hard acceleration literally dumps fuel into the engine bypassing all economy and emissions controls. I have tried this with a Ford Taurus. Under hard acceleration, fuel economy is .25 MPG! Heck, I tried this with a 1938 Ford pickup using a quart jar on the cowling feeding fuel to the engine. I could not believe how fast the fuel level went down. Like in 2 seconds. So much for that. As for thermostat cycling, the cycling rate does not come in to play unless the structure has reached the set temp. Once the set temp has been reached, the thermostat must now anticipate the loss in temp and be able to start the furnace before the loss is sensed by the temp sensing part of the thermostat. And in addition must shut the furnace down before the sensing part of the thermostat senses the change. This can be accomplished by electronics or by a preheater in a mechanical thermostat. GFM
@@grayfurnaceman The idea is that with a wide open throttle you minimize mechanical pumping losses and also achieve the same distance in a shorter time versus slow acceleration where the throttle is mostly shut for a longer time. What about the temperature differential for the thermostat. How does that factor into the cycles per hour? Seems like it would be variable depending on the cycles per hour.
question. hey furnace man you are great, i ran into a sytem i coulnt fix... brand new install txv and r410 a... i looked at the system and found a 0 degree subcool, so i said hey thats the problem... i added the refridgerant and subcool would rise but then it would fluctuate, and i couldnt get it figured out. i guess it was the liquid line temp moving up and down cousing it becouse we mesured the temp there and it would move from 103 degrees to 109 degrees... i tought mayby it was just a bad vacuum but ive only been doing this for 1 month have no clue... thanks for the help
My furnace is only cycling once per hour with my new gas furnace and two repair visits have failed to correct the problem. I live in a very cold climate here in Edmonton, Alberta, Canada and the cycle of my furnace is about 7 minutes on and 1 hour off at maximum setting on a new Honeywell thermostat. A one hour shut down when it is below freezing all day and night results in a very uncomfortable indoor environment in a very short time. Please help me with advice. I heard the repairman say that he set my thermostat's anticipator at 0.8
There is something else going on here. Try setting the thermostat as high as it will go and see if the furnace stays on for, say 20 minutes. If it stays on, the problem is in the thermostat. If not, look at the furnace. GFM
@@grayfurnaceman No, it does not stay on at maximum setting but another visit from a servicing vendor said that it is the location of thermostat sending mixed messages to the furnace to go into "lockout". I will be receiving a new digital thermostat in a better location in a few days. It will be a low temperature of minus 26 Celsius ( minus 14.8 °Fahrenheit) tonight.......gee ,only in Canada, pity.... i hate winter here in Edmonton,Alberta,Canada.
i have set from 6 to 3 to test, its clearly start to burn more gas id say 15% more.. than it was 6 cycles per hour.. I have UFH 80 sq/meters, and no radiators. I wonder when you should use more cycles per hour, ? :D o what temperature you have to make hot water for system i have set now 40 degree, outside we have like -2 to 0degree celsius.
Would you do a comprehensive video or series of videos teaching checkouts? I'd really like something that I can watch repeatedly that would help ingrain that particular information into my brain. I'm about 5 months into the industry, 36 years old, EPA for about 1 1/2 years but have only been doing installs for about 5 months. I was an apartment management maintenance person prior.
Sorry, that might not have been a very reasonably request. I do have another question though. What would cause subcooling to rapidly fluctuate between 4 and 10 degrees with pressures also fluctuating between 20 psi or so?
I'm very worried that I may have a kink in my new lineset that I didnt catch or something. My head pressure fluctuated between 270 ish and 300psi while my subcooling fluctuated between 4 and 10 degrees. This was while trying to get subcooling numbers to make sure my charge was correct before calling the install "complete".
I have a 80s Luxair furnace with Honeywell fan limit switch, and Honeywell programmable thermostat. If I change CPH from standard 5 to 3, will I need to change fan limit switch settings? I don't want to overheat the heat exchanger.
I'm still lost, does the CPH prevent the unit from running more than the set cph? So if the thermostat is set for 3cph and it has already ran 3 cycles in that hour will it cause a droop until next timed cycle even if demand is there?
I can't figure out how to adjust my cph on my Honeywell vision pro 7 day programmable t stat. My gas furnace cycles 6-8 times an hour. Even my AC in summer cycles 5-7.
You can find the video by using the link "Thermostat" for the playlist. Or you can use the link toward the end of the video "For the next in this series"
CPH I got a CT87N Thermostat from honeywell, but it cycles way more than my old one. AC cycle is 7 minutes vs the old 15 mins. Has 9CPH listed for electric AC and Heat. It has 3 CPH for gas/oil. It's not a heat pump though. It has settings for 1 CPH - 9 with recommendations based on heating furnace type. Anyway, I just want AC and Heat to cut on 2-3 per hour. The constant cycling can't be good for the AC capacitor or compressor, but I'm unsure if the blower motor will stay on long enough to cool off the heating element when it kicks off. Don't know how these settings affect that if at all.
My experience has told me to set these things much lower than the manufacturer recommends. 3 CPH should will work well for both heat and cool. The only reason to have shorter cycles would be if the structure loses heat very quickly. GFM
Thank you. I live in the south so our heating unit are puny and inefficient. We do everything we can to keep our AC running though, haha. With the humidity longer cycle times is very important too.
This is a training series on how thermostat cycling operates. The how to depends on what type of thermostat you have. If its mechanical, this one may help: ruclips.net/video/UhXnZtOO86Q/видео.html If it is electronic, it could set by the manufacturer and cannot be changed. Some thermostats have an installer setup where you can change the cycling. This varies with manufacturer. Sorry I could not make it simple, but that is how it is. GFM
Just Google your thermostat model plus the word "manual"... If it's not a completely digital unit the instructions should be some variant of "remove the cover, locate the slide, lever, or dial with numbers like .2 .4 .6 .8 1.0 1.2, etc. Then just move it to the appropriate position and replace the cover.
*Works as expected **Fastly.Cool*
Sir thank you. An Hvac tech was here 2 days ago and I asked him is there something in settings I am missing. He told me everything looks fine. Stumbled across your video and sure enough the cycle was set to 6. I turned it down to 2. Hopefully this will fix the ridiculous light bill. Thank you
THANK YOU!
I absolutely love and appreciate your vids
👍
Thanks for the support.
GFM
grayfurnaceman
Today was a day I came across an oversized system. ~100,000 btu of heat output in a space that needs only 50,000 btu. Space was split in two. All of the ducts are in the new (1/2 sized space). When heat comes on the space is heated quickly and overshoots the set point. When heat cycles off, it stays warm long enough. Everyone there is very UNCOMFORTABLE
What would be a good cycle per hour setting ?
There is no real solution to the problem. I guess I would shoot for 6 cycles. I would say more but most stats won't do it.
GFM
grayfurnaceman
Thanks
Did I misunderstand something? If furnace is oversized, holds and maintains temp, people are uncomfortable, why would you increase cph instead of decrease? I must of missed something.
FYI the car analogy you made is actually incorrect. Road & Track had an article in the December 2000 issue that showed rapid acceleration was significantly more efficient than slow acceleration and cruise. I know it seems counterintuitive.
What Im wondering is what the algorithm looks like for the thermostat to cycle a set number of times per hour.
It is not only counterintuitive but it is wrong. I would love to look at the magazine but I could not find it on the internet.
Hard acceleration literally dumps fuel into the engine bypassing all economy and emissions controls. I have tried this with a Ford Taurus. Under hard acceleration, fuel economy is .25 MPG! Heck, I tried this with a 1938 Ford pickup using a quart jar on the cowling feeding fuel to the engine. I could not believe how fast the fuel level went down. Like in 2 seconds.
So much for that.
As for thermostat cycling, the cycling rate does not come in to play unless the structure has reached the set temp. Once the set temp has been reached, the thermostat must now anticipate the loss in temp and be able to start the furnace before the loss is sensed by the temp sensing part of the thermostat. And in addition must shut the furnace down before the sensing part of the thermostat senses the change. This can be accomplished by electronics or by a preheater in a mechanical thermostat.
GFM
@@grayfurnaceman The idea is that with a wide open throttle you minimize mechanical pumping losses and also achieve the same distance in a shorter time versus slow acceleration where the throttle is mostly shut for a longer time.
What about the temperature differential for the thermostat. How does that factor into the cycles per hour? Seems like it would be variable depending on the cycles per hour.
question. hey furnace man you are great, i ran into a sytem i coulnt fix... brand new install txv and r410 a... i looked at the system and found a 0 degree subcool, so i said hey thats the problem... i added the refridgerant and subcool would rise but then it would fluctuate, and i couldnt get it figured out. i guess it was the liquid line temp moving up and down cousing it becouse we mesured the temp there and it would move from 103 degrees to 109 degrees... i tought mayby it was just a bad vacuum but ive only been doing this for 1 month have no clue... thanks for the help
My furnace is only cycling once per hour with my new gas furnace and two repair visits have failed to correct the problem. I live in a very cold climate here in Edmonton, Alberta, Canada and the cycle of my furnace is about 7 minutes on and 1 hour off at maximum setting on a new Honeywell thermostat. A one hour shut down when it is below freezing all day and night results in a very uncomfortable indoor environment in a very short time. Please help me with advice. I heard the repairman say that he set my thermostat's anticipator at 0.8
There is something else going on here. Try setting the thermostat as high as it will go and see if the furnace stays on for, say 20 minutes. If it stays on, the problem is in the thermostat. If not, look at the furnace.
GFM
@@grayfurnaceman No, it does not stay on at maximum setting but another visit from a servicing vendor said that it is the location of thermostat sending mixed messages to the furnace to go into "lockout". I will be receiving a new digital thermostat in a better location in a few days. It will be a low temperature of minus 26 Celsius ( minus 14.8 °Fahrenheit) tonight.......gee ,only in Canada, pity.... i hate winter here in Edmonton,Alberta,Canada.
i have set from 6 to 3 to test, its clearly start to burn more gas id say 15% more.. than it was 6 cycles per hour.. I have UFH 80 sq/meters, and no radiators. I wonder when you should use more cycles per hour, ? :D o what temperature you have to make hot water for system i have set now 40 degree, outside we have like -2 to 0degree celsius.
Mine turns on at about every ten minutes at night. Less in the day. But it's tiny home with bad door seal.
About right
GFM
Would you do a comprehensive video or series of videos teaching checkouts? I'd really like something that I can watch repeatedly that would help ingrain that particular information into my brain.
I'm about 5 months into the industry, 36 years old, EPA for about 1 1/2 years but have only been doing installs for about 5 months. I was an apartment management maintenance person prior.
Are you asking for a series that covers troubleshooting from the most basic to complex?
GFM
Sorry, that might not have been a very reasonably request. I do have another question though. What would cause subcooling to rapidly fluctuate between 4 and 10 degrees with pressures also fluctuating between 20 psi or so?
I'm very worried that I may have a kink in my new lineset that I didnt catch or something. My head pressure fluctuated between 270 ish and 300psi while my subcooling fluctuated between 4 and 10 degrees. This was while trying to get subcooling numbers to make sure my charge was correct before calling the install "complete".
Sorry, its an r410a 3 ton unit with a txv.
Basically I'm sitting here hoping to god that I didnt "F" something up.
I have a 80s Luxair furnace with Honeywell fan limit switch, and Honeywell programmable thermostat. If I change CPH from standard 5 to 3, will I need to change fan limit switch settings? I don't want to overheat the heat exchanger.
No, the cycling rate has no effect on the internal temp of the furnace.
GFM
Thank you, happy new year
Does the cycle time or number of cycles setting on a thermostat affect the number of cycles on cooling as well as on heat setting?
There is generally a separate cycling rate set for cooling either mechanically or by programming.
GFM
How do I set the cycle
I'm still lost, does the CPH prevent the unit from running more than the set cph? So if the thermostat is set for 3cph and it has already ran 3 cycles in that hour will it cause a droop until next timed cycle even if demand is there?
The CPH is only in use when the inside temp is stable. If the temp drops the unit will come on.
GFM
Thanks
I can't figure out how to adjust my cph on my Honeywell vision pro 7 day programmable t stat. My gas furnace cycles 6-8 times an hour. Even my AC in summer cycles 5-7.
I can't be sure which model you have but usually installer setup numbers 220 to 270 control CPH.
GFM
Does this go for gas boilers as well?
Boilers have longer cycles. Especially if you have in floor heat.
GFM
I think I have the 2 zones/stats that are fintube set to 3 cph, and the 1 basement infloor heat zone set to 1 cph. Does that sound about right?
It sure does.
GFM
Great, thanks. Love the vids btw..Keep them coming!
Where's #2?
You can find the video by using the link "Thermostat" for the playlist. Or you can use the link toward the end of the video "For the next in this series"
ruclips.net/video/QixDGFFfwtU/видео.html
thanks for sharing ...
I JUST TIMED IT RUNS 10 THEN OFF 3 MIN. IS THAT NORMAL
Does not appear normal. Very long run time compared to off time. Mechanical or electronic thermostat?
GFM
My thermostat is set to 3 cycles per hour. Runs about 7 or 8 minutes and then stops for7 or 8 minutes. Single speed gas furnace. Is this normal?
That would be 3.75 CPH. Pretty normal.
GFM
grayfurnaceman thanks. I was worried thinking the furnace wasn’t working properly. Your videos are very helpful
What do you recommend for an electric forced heat?
Are you talking brand?
GFM
CPH I got a CT87N Thermostat from honeywell, but it cycles way more than my old one. AC cycle is 7 minutes vs the old 15 mins. Has 9CPH listed for electric AC and Heat. It has 3 CPH for gas/oil. It's not a heat pump though. It has settings for 1 CPH - 9 with recommendations based on heating furnace type.
Anyway, I just want AC and Heat to cut on 2-3 per hour. The constant cycling can't be good for the AC capacitor or compressor, but I'm unsure if the blower motor will stay on long enough to cool off the heating element when it kicks off. Don't know how these settings affect that if at all.
My experience has told me to set these things much lower than the manufacturer recommends. 3 CPH should will work well for both heat and cool. The only reason to have shorter cycles would be if the structure loses heat very quickly.
GFM
Thank you. I live in the south so our heating unit are puny and inefficient. We do everything we can to keep our AC running though, haha. With the humidity longer cycle times is very important too.
Thanks for nothing you didnt shiw how to
This is a training series on how thermostat cycling operates.
The how to depends on what type of thermostat you have. If its mechanical, this one may help: ruclips.net/video/UhXnZtOO86Q/видео.html If it is electronic, it could set by the manufacturer and cannot be changed. Some thermostats have an installer setup where you can change the cycling. This varies with manufacturer. Sorry I could not make it simple, but that is how it is.
GFM
Just Google your thermostat model plus the word "manual"... If it's not a completely digital unit the instructions should be some variant of "remove the cover, locate the slide, lever, or dial with numbers like .2 .4 .6 .8 1.0 1.2, etc. Then just move it to the appropriate position and replace the cover.