Another HeatPump Question

lenOrge · 02-22-2007, 08:59 AM

Hi...My rooftop heat pump (Coleman) will only run for a few seconds,then shuts down.I could not find a similar situation in the archives. Up to this point it was running fine.Any suggestions. Thanks. lenOrge

2003 Brave 34D
2001 Tracker

lenOrge · 02-22-2007, 08:59 AM

Hi...My rooftop heat pump (Coleman) will only run for a few seconds,then shuts down.I could not find a similar situation in the archives. Up to this point it was running fine.Any suggestions. Thanks. lenOrge

2003 Brave 34D
2001 Tracker

Richard 34A · 02-22-2007, 09:44 AM

I can't help with your specific question but did come across this link trying to research my question regarding heat pumps.

Doesn't give any cause or symptoms but might help you in terms of parts.

http://www.rvcomfort.com/pdf_documents/r407.pdf

RV Comfort website is rvcomfort.com / 877.430.8084

Here's another link to check out, depending on your model number.

http://www.rvcomfort.com/rvp/tech_info/operation.php

paz · 02-22-2007, 01:06 PM

lenOrge, what is the outside temperature where you are? Heat pumps usually only work down to about 40 degrees. If the temperature is lower, they may try to start, but then shut down.

lenOrge · 02-22-2007, 01:19 PM

Thanks "paz"...but it's in the low 70's today. I checked the sites that Richard 34.5A gave, but there was no trouble shooting there. lenOrge

2003 Brave 34D
2001 Tracker

GaryKD · 02-22-2007, 02:47 PM

Hi lenOrge,
Can you be a bit more specific.
1. Is this the front or rear or only unit in the coach?

2. Where is the sensing (thermistor) unit located? The unit that senses the temp and would tell the Colman to turn on/off. Is it on an outside or inside wall? If on an outside wall is there a connection of the sun hitting the side of the coach the thermistor is on and the short cycling? Is it in the direct path of air movement?

3. It's in the 70's and you have the heat pump on. Have you done this before with the outside temp in the 70s?

My questions are based on the assumption that the Colman is okay. I have had this problem with my rear heatpump unit. After much broo ha ha, it turned out to be the thermistor was on an outside wall. This was causing the unit to short cycle. I changed the placement of the thermistor and now all works fine.

RV Wizard · 02-23-2007, 12:09 AM

lenOrge, only set the thermostat a couple of degrees warmer than the inside air temperature if using the heat pump; otherwise it is designed to shut down and bring on the furnace. I believe the threshold is 4 degrees. Any more than that and the heat pump could not satify and uses the furnace to do so. Once you get the coach to a comfortable temperature it should be able to maintain to about a 42 degree ambient outside temperature where again it will switch to furnace. GOod luck and let us know how it goes.

lenOrge · 02-23-2007, 10:26 AM

Thanks RV Wizard...I tried what you suggested, but it still didn't work. Before I read your post I tried it with the generator and it ran for a few seconds. Then when I read your post I tried it again. This time it didn't even try to start. The a/c works good thou. Thx again. lenOrge

RV Wizard · 02-24-2007, 01:32 AM

lenOrge, don't forget about the time delay as the unit compressor will not start for a few minutes after turning it on. If it still does not start you might start looking for loose connections.

jdynan · 02-24-2007, 04:45 AM

I have an 04 Adventuer, heat pump system, but the same problem last Dec. Many searches finally brought me to the possible cause. There seems to be a problem with the Thermostat printed circuit board in models before 05. I took a chance that was the problem and ordered one from Litchensen RV, in Forest City (spelling optional). It cost about 140.00 but solved the problem. I asked them if this is common and they had some in stock which is a good indication. This may not be your problem but it's and easy replacement and may help. Good luck

RV Wizard · 02-25-2007, 01:59 AM

jdynan, welcome to the forum.com. We are glad to have you join us and thank you for the info on the t'stat. Be sure to stop by the New Members section and introduce yourself. You will find we are eagar to help each other out where we can. Take care.

lenOrge · 02-25-2007, 09:33 AM

jdynan & RV Wizard...Thanks for the help.I used the system all summer (Cape Cod,MA) with no problem. I guess I will have to look into the circuit board theory. lenOrge

2003 Brave 34D
2001 Tracker