Community Forums

GaryL · 06-26-2008, 02:35 AM

Help!!! it's hot. Some one knows the answer to this problem. It is going to be 90 degrees today and my front air is not working right. It will come on and give cold air for about 5 min. then the heat pump will come on and the air turns hot. Where should I look for the prob. and how can I fix it? Any help will be apprieceated. Thanks. Gary

GaryL · 06-26-2008, 02:35 AM

Help!!! it's hot. Some one knows the answer to this problem. It is going to be 90 degrees today and my front air is not working right. It will come on and give cold air for about 5 min. then the heat pump will come on and the air turns hot. Where should I look for the prob. and how can I fix it? Any help will be apprieceated. Thanks. Gary

Hitchhiker · 06-26-2008, 03:31 AM

Are you certain the heat pump actually turns on or are you presuming that to be the case because the AC is blowing hot air? The diagnosis of an AC blowing hot air would be different from diagnosing one that had reversed it's cycle and switched to 'heat pump'.

It'd be exceptional if it were running on 'heat pump' while the outside temps are in the 90's.

GaryL · 06-26-2008, 04:25 AM

Yes Hitchiker, I am absolutjy sure the heat pump is starting up, The air is very hot. This morning when it is cool out side I tried the air and 6 min. later the heatpump came on and the air was HOT. GARY

Hitchhiker · 06-26-2008, 04:37 AM

Interesting, maybe there's a problem with the reversing valve or the associated circuitry that controls it? I'll link this thread to the RV Systems and Appliances forum, maybe some of the techs who watch there will have a suggestion to help.

dveasey · 06-26-2008, 08:08 AM

I think that you're confused about the heat pump coming "On".It's not "heating"... It sounds like possible freezing of the coils & the compressor laboring under the strain.You need to visually inspect the rooftop evaporative coils.

See this thread:http://irv2.infopop.cc/eve/forums/a/.../m/10210865541

RV Wizard · 06-27-2008, 12:47 AM

Gary, we will need some specific info of the heat pump; year, make & model. What position do you have the t'stat set on? Are you able to troubleshoot electrical and electronic circuits with a schematic?

GaryL · 06-30-2008, 02:56 AM

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by RV Wizard:
Gary, we will need some specific info of the heat pump; year, make & model. What position do you have the t'stat set on? Are you able to troubleshoot electrical and electronic circuits with a schematic? </div></BLOCKQUOTE>The air is aDometic mod. 620515. On 2005 Mount. Aire, With a 5 button Duo-Therm Control Center. My elcetrical knowledge is basic. It sounds like freeze up on the coils when it kicks out hot air that lasts for 2-3 min. then the cooling pump comes on and cools for 5 min. then back to heating. I am thinking about taking to RV repair soon.

RV Wizard · 06-30-2008, 02:09 PM

GaryL, have you checked the coil and air filter? You could have a short cycling of discharged air back into the return causing a freese up condition if it is not the air filter or dirty coil. Otherwise electrical troubleshooting will need to be done.

sparetire · 06-30-2008, 08:17 PM

Gary,

Here's a possibility:
It could be the built-in (to the A/C unit)resistance heater coming on, overpowering the cold air or coming on and compressor switches off. Even heat pumps have resistance heaters in RV's to supplement the heat pump (A/C system flow just runs in reverse) at temps lower than 35 F degrees. T-stat bad or mis-wired, unit mis-wired, relay stuck, or bad electronic control are a few things that could cause the above problem.

GaryL · 07-01-2008, 02:19 AM

Thanks for all the suggestions. I was talking to another camper last nite who had the same problem, it turned out to be a circuit board so, I am taking it to an RV repair shop today. Thanks again. Will let you know what they find.

HPH · 07-01-2008, 06:24 PM

Gary,
It sounds like your reversing valve is dropping out. If yours is like mine the reversing valve energizes during the cool mode and defaults to heating mode(heat pump) when there is no call for cooling. You will hear a swooshing noise when the ac shuts down. The T-stat is wired to send a signal to energize the reversing valve solenoid when the unit calls for cooling. Your solenoid coil may be overheating or defective and dropping out causing the unit to run in heat mode no matter what mode the t-stat is set in.
Basically if the Reversing valve does not energize you will get heat only. I'd ck to see if the RV solenoid has pwr. during cool mode and then see after the 5-6 min when it starts to run in HP mode if it's switching over or losing it's signal from the t-stat.
HPH

GaryL · 07-04-2008, 03:25 AM

I took the M/H to an Rv service place, they called Dometic who said it needed a new board, after waiting for new board and install found out that was not the problem. then dometic said it was prob. reversing valve, service said because it required soldering they could not fix it, wanted to install new A/C for 1200 plus, no thanks. I am now searching for a real A/C guy who knows what he is doing to diagnos and fix. I do believe HPH that you are on the right trac and this is where I stand. Thanks for all suggestions again. Gary

RV Wizard · 07-05-2008, 01:35 AM

Gary, if in fact it is the reversing valve, and it does cool properly for a time I would think it is the solenoid on the valve and not the actual mechanical valve. If this is true, you should only have to replace the coil on the valve and removal of refrigerant and replacing valve body would be unneccessary. It certainly would be worth the try first. Good luck and have a great weekend.