Heat pump t-stat issues

[nonhog]

Just replaced the T-stat wchich was supplied by the guy who installed our heat pump. We have Propane as a back up system but the whole switch over has never gone smooth. Often(before todays t-stat replacement) it will run and run but not reach the desired temp. So we would switch over to propane which is nicer cozy heat but very expensive. Shouldn't need to do that over 35* according to my installer. Now and again it would pump very cold air not the cool air that heat pumps are known for. So I decided that I would just pay to have the t-stat swapped out and the tech says no problem I'll contact you.
(at no charge) we play phone and text tag until I am basically ignored.
So I swap the t-stat today and its worse than before. I swapped wires one by one matching and verified by taking a picture before I started.
NOWit wont heat up, has no "Emergency Heat" even listed. And when run on Cool it blows warm air.

Making a phone call to the owner tomorrow unless someone can show me how I goofed (possible I guess)
This has gone on for a couple years, really bummed its worse not better.


Honeywell VisionPro IAQ stat if that helps

 

[firebirdparts]

heat pumps pump "very cold air" now and again when they defrost. What you are getting is air conditioning at that moment. That is not something the thermostat can control.

This can be disguised by running 'stage 2' heating right when you are defrosting. If your system was firing up the propane just for a minute or two while defrosting you would not have noticed that. That is also not something the thermostat can control. The outside unit controls it.

Thermostats are surprisingly difficult to install in my opinion. there is no standardization of wire colors at all. Modern heat pumps generally use an either/or system where the 4 way valve is energized when heating or when cooling. You have to know which. The thermostat is always made to work either way. If it blows heat when cooling, then you might have that part of it reversed which is easily fixed.

 

[nonhog]

Propane furnace is a Payne PG8JAA which works great I doubt its a contributor to any of our problems
Heat pump is a Johnson Control, York LX series?

 

[nonhog]

heat pumps pump "very cold air" now and again when they defrost. What you are getting is air conditioning at that moment. That is not something the thermostat can control.

This can be disguised by running 'stage 2' heating right when you are defrosting. If your system was firing up the propane just for a minute or two while defrosting you would not have noticed that. That is also not something the thermostat can control. The outside unit controls it.

Thermostats are surprisingly difficult to install in my opinion. there is no standardization of wire colors at all. Modern heat pumps generally use an either/or system where the 4 way valve is energized when heating or when cooling. You have to know which. The thermostat is always made to work either way. If it blows heat when cooling, then you might have that part of it reversed which is easily fixed.

I get the colder than "cool" air but it is something the stat should notice if the temp is beyond its 3 degree span, at least that is how it was described to me.
Therefore the stat is not giving a signal when it should as our system was not switching as designed as it would blow cold air for an hour or better then my wife would turn the stat to EM heat.
.
As for the new stat, installed today, It looks identical to what I swapped out but your thinking it could be wired differently?

Thanks for the reply!

 

[nonhog]

Just checked the back of each lid. Old and new both wired the same.
Both THM5421C.
Could I have fried something? I noticed the LED flickered while I was swapping it out. I flipped the breaker but obviously it gets power elsewhere.

Hate to throw in the towel but I am tired of this. Maybe sleep will help.......

 

[bazar01]

Digital thermostats need to be configured for each unit type.

 

[yeldogt]

Payne is the Carrier "basic" line -- they also make Bryant (typically sold by oil dealers). Why did he not install a Carrier control?

The heat load on the house and the output of the HP determined the switchover -- at some point the unit can't supply enough heat and it has to switch over to propane .. you don't want it to use the resistance heat (electric heat strips) unless your electric is cheap.

Basic HP will give you cold air when defrosting -- the more complex systems have other strategies to minimize this as well as only doing defrost when needed. Many of the basic systems defrost on a timer -- so they defrost when its actually not needed.

Can your system run the HP with partial resistance -- some can do this. It allows a lower set point/ changeover to propane ... again all of this depends on electric costs and common temps in the area .. and if the unit can do this.

Many of the newer VS HP's don't have back up heat they can run down to very low temps .. I hope this not new .. you would have been better served with a different unit.

 

[acmikee]

I would suspect that your new tstat program is not correct. put the old tstat onto the new subbace see if it works,

 

[Falcon67]

We had to change out out t-stat from a Filtrete to a Honeywell on our new (last year) heat pump. It just would not run the system very well. On the Honeywell, e-heat kicks in on a greater than 2 degree differential between ambient and set point. So we revised our setbacks to only do 2 degrees. AFAIK, the Honeywell doesn't have a config setting so I can change the e-heat kick in. All in all, the Honeywell runs the system well enough but is a bit of a $100 POS. Wifi in the unit has also already failed. Works but not recommended.

 

[yeldogt]

Be careful with setbacks. Properly designed systems should have minimal setbacks -- they are designed to run longer and don't have the extra capacity for setback recovery.

It's actually cheaper to have a proper system running with only a small setback depending on insulation -- drop in temp over night. With a HP -- the recovery will require the electric back up to come one ... often at 3x the cost to run.

 

[nonhog]

Payne was existing Propane furnace. We use to heat by woodstove but went to heat pump for many reasons. Maybe I should push the repair guy to try a different brand t-stat?
Makes my head hurt trying to understand how I could have screwed up the install doing one wire(wires) at a time.
Unless I botched the inside portion which only had 3 wires but I stared for awhile before swapping. Confident (or I was at least)
I think I better call the company and skip my installer.

Thanks everyone for input, nice to have support.

PS my car wouldn't start this morning. I fixed that!

 

[nonhog]

I would suspect that your new tstat program is not correct. put the old tstat onto the new subbace see if it works,

Might try that tonight.

 

[sms1974]

if there's no emergency heat mode you have the wrong thermostat, or it is not set up correctly... heat pumps require different signals from the thermostat than a gas furnace. also if the system is not wired and set up properly you will never be comfortable.

when your heat pump goes in to a defrost cycle your propane furnace should come on to supplement the supply air temperature. the defrost cycle is basically putting your heat pump in cooling mode for a few minuets to warm the outdoor coil and clear it of ice. no getting around this with a heat pump so when it does that it brings on the furnace to compensate for air temperature and to aid in getting some heat to that outdoor coil...

sounds to me like you need a new heating contractor that knows how to set up a heat pump the right way...

 

[sms1974]

after rereading this thread, I skimmed by most of it, oups.... your set up is wrong... you will need to get in to the setup menu, Installer set up Item number 0172 needs to be set to 2 this tells it that you have a heat pump...

i would still recommend a new contractor take a look at your system

 

[nonhog]

Got home and swapped the old stat back in, got heat back in the house!
My installer did contact me and said the issues are in the "installer programing" of the stat. Something not easily figured out. I am happy we have heat! And happy I wired it up correctly. Now to get the new one reprogramed and hopefully it'll transfer when needed. I'll post the outcome. Thanks everybody!
Its not over yet. (temporary satisfaction)

 

[bazar01]

Glad you got it working in heating mode.
Hope it works also in cooling mode. It is starting to warm up.

Nothing wrong with diy. Just spend some time to research and learn.
Controls is just one of the skills requirement of this trade.

 

[nonhog]

Glad you got it working in heating mode.
Hope it works also in cooling mode. It is starting to warm up.

Nothing wrong with diy. Just spend some time to research and learn.
Controls is just one of the skills requirement of this trade.

Warm up? Not in these parts. (Seattle) we will get our three weeks of hot weather split up between July and August. LOL.

I do love the DIY stuff but my list is longer than my life expectancy assuming I live till 120.

 

[firebirdparts]

Good luck with your thermostat programming. I do it all the time and I still get confused.

 

[Falcon67]

LOL, we haven't run the heater since early February. It's been all AC since then.