Trane xl 1400 heat pump low heat temp output

[paschal_old]

I am in a state of total disbelief of what I am seeing and my glasses are working well. Back in late March I posted about low heat ouput temperatures. However I did not pursue the issue, as cooling season hit and I let it slide. However heating season is back and the issue is still there.

For unit information etc the post is here http://applianceguru.com/forum13/19574.html

This is what is newly discovered and weird. I was bumping the thermostat up a degree at a time to keep the backup from kicking in on dog bath day, Then I notice that the monitoring thermometer hanging from the ceiling register, goes up 1 degree for every 1 degree that I raise the thermostat. Tstat at 74.....airflow at 80..............tstat at 73, airflow at 79.........tstat at 72, airflow at 78........tstat at 71, airflow at 77............and so on.

I have been performing this exersize for over two days and get the exact same result each and every time. I promise you folks that I am seeing this, over and over, but not believing it. How could this be possible. I am sure it somehow gets back to Mo or Ron who installed this system.

[Cactus Bob]

your link goes to  404 NOT FOUND  please post you information again .. also... how old is this unit ? ...

[RegUS_PatOff]

this is what's INSIDE the posted link (if you roll your mouse over it)

http://applianceguru.com/forum13/forum13/19574.html

                                            ^ ^ ^ ^    ^ ^ ^ ^

this is what it should be

http://applianceguru.com/forum13/19574.html

 

[paschal_old]

Hey: Cactus

The unit is about 7 years old. Problem started last year...suggestions?

[ACtechGUY]

Forget about the thermostat. What you are observing is coincidence. A thermostat is a switch . It is either on or off. It cannot be something in between.

If your system cooled well enough in the summer then your refrigerant level is probably OK. It takes far less refrigerant to produce acceptable heat levels than it does to provide sufficient cooling.

Their are several possible causes for low heat output. One of them is the REVERSING VALVE is not seating all the way in the heating position..

Go out and look at the condeser while it is running in heat. Take off the side panel and make some observations. Like , Each and every pipe temperature. is anything frosting up? if so where?

All this said... unless you have pressure gauges , you will never really know what is going on in there.

[paschal_old]

Thank you ACTechGuy. That is a bit of helpful new info, and sounds very rational. I thought the reversing valve was a yes or no thing. I get a slight surge of higher temp air and then it falls off within 30-45 seconds which kinda falls in line to what you stated. I think I have almost enough to call a NATE certified guy out here. Any other suggestions at this point greatly appreciated.

[paschal_old]

I FOUND THE PROBLEM!

I FOUND THE PROBLEM!

At least it seems that way!!!

PUT THIS ONE DOWN IN YOUR BOOKS GUYS AND GALS!!!!

When it got really cold here, well over a week ago, the problem with low temp output except in aux mode got worse. System ran continually....kept watching the vent temp and it was dropping into the 50's, cooling the house down till aux kicks in, then kicks out and would run 70's and then back into 50's over and over and over.

I happened to be in the garage digging around in the freezer for food while heat pump was blowing 50's and realized the compressor was not running.  Then logic started to kick in.....Chronotherm III thermostat has a processor and memory, just like a computer.....It must be confused and is just cycling air from the upstairs attic return which would be pretty chilly in the winter.

Yesterday I pulled the thermostat out after killing all power, cleaned the contacts, put in new alkaline batteries after cleaning their contact points, and put it all back together. Within 15 minutes after a restart, the air handler turned off for the first time in over a week. As I sit here now 32 degrees outside, the air flow in the vent with a 10 inch temp probe is hitting 80 degrees after the aux has been cycled only for a very few minutes. Then, I get a normal shutoff cycle. The tstat is set at 68. I just checked again after about 30 minutes. 35 outside and blowing 81.5 without the aux on.

So if anyone thinks that a lowly tstat can't reek havoc on a heat pump. I will strongly disagree that point.

I will add to this post when it warms up a bit more after the first of next week.

[Pegi]

Cool post...thanks for the information...keep us posted if this changes...

[paschal_old]

Thanks for the comment Pegi! Maybe HVAC post of the month?????

If anything changes, I've already found a dealer that sells the Honeywell 6320u1000 which is a direct replacement for the Chonotherm III (The particular model I have is called for as a 3/2 replacement. The wiring looks almost identical from my unit compared to the install manual for the 6320u1000.

[Pegi]

Ya, with cold weather time it makes it important to have the heat working properly, I would change that thermostat asap....this is good information and might help others who reads the threads...keep someone from freezing to death....

[ACtechGUY]

Most high quality replacement thermostats these days will work with any system you can throw at them including heat pumps with 3 stages of heat. Don't lock yourself into a "direct replacement" of a chronotherm III. There is no reason to. There a ALOT of great thermostat options out there.

Honeywell stats

http://yourhome.honeywell.com/home/Products/Thermostats/7-Day-Programmable/SummaryList.

I use the VisionPRO 8000 7-Day Programmable Thermostat ALOT. Many manufacturers use the 8000 branded under their own name.

Venstar stats

http://venstar.com/Thermostats/

I also use the The Slimline Platinum Series often.

These guys are very flexible, they have all kinds of attachments and goodies. CARRIER brands these as their own.

[ACtechGUY]

I have to take issue with the what was said in the other thread you posted.

this can be caused by a thermostat....No, they are not just off and on!!!!!!!!!!!! They have a brain and can get confused!!!!!

Yes, Thermostats do get confused and do stupid things. But it is still either energizing an output or not energizing an output. The compressor outside was not running because the thermostat was not energizing the Y signal at random.

Do not confuse random operation as not ON or OFF.