AC problems again

[12th_Man_Fan]

I have a Penguin II heat pump/AC that I am having issues with. My RV is a 2015 and both units have been replaced under warranty.

Today it is what I would call short cycling. I can set the temp as low as 65 and it will come on and the compressor will run for awhile then it will go off but the fan keeps running. After awhile the fan will cut off but will start again in just a few seconds and the compressor will start again.

This continues over and over and over and it has no bearing on what the inside temp actually is. Eventually the compressor will quit coming on and the fan will run until I turn it off.

The coils are clean and I have re-set the thermostat, this is all I know how to do.

Any suggestions are appreciated.

By the way when the compressor is running the air is cold.

Also the heat pump function works as it should. We are using it each morning in Colorado.

[enblethen]

Thanks for the update!

[12th_Man_Fan]

Well the AC worked all day with no issues so the problem was the freeze thermister.

Thanks all for your help.

[enblethen]

Let us know on this post as what happens!

[12th_Man_Fan]

Both AC's had worked just fine B4 I left Texas. This was a new problem that developed while in Colorado high altitude. Sorry I didn't clarify that sooner.

I switched the sensors this morning and as soon as I turned on the front AC on which was the unit I put the bad sensor in gave me an E5 error which is open ckt or out of range freeze sensor. So far the back unit is working as it should.

I pulled the bad sensor out again and sure enough it was open ckt when I checked it with a VOM meter. I wish I had checked it before I sent to the trouble of installing it in the front unit.

New sensor on order.

Thanks everyone for you help. I know just enough to be dangerous on things like this.

I am getting too old for this kind of stuff. Four trips to the roof! Yuck.

[dougrainer]

enblethen wrote:
Even if they come with new boards they still need to be set up.
I didn't see whether this is same issue as you had with original AC units that were replaced.

Yes and no on set up. Zone 1 is a default and will be the front unit. Zone 2 MUST be set and will be bedroom. If Zones NOT set up, then the system will not function at all. So, his zones are set correct. The ONLY other set up that he would need is to tell it has a furnace. But if not switched to furnace it would have no bearing on his Cool operation. Doug

[enblethen]

Even if they come with new boards they still need to be set up.
I didn't see whether this is same issue as you had with original AC units that were replaced.

[Lynnmor]

I didn't see where the input voltage was checked.

[12th_Man_Fan]

Thanks for you help Doug & emblethen. I am going to swap the thermistors in my ac's today and if that is the problem I will order new one.

Thanks again for all your help.

[dougrainer]

12th Man Fan wrote:

enblethen wrote:
Did they replace or setup the control boards?

I assume they did. Don't new units come complete with new control boards?

NEW PENGUIN's come with onboard 10 button control boards. Doug

[dougrainer]

https://www.amazon.com/Dometic-3312303005-Thermistor/dp/B00T36USKY/ref=asc_df_B00T36USKY/?tag=hyprod...

[enblethen]

Locate the thermistor, There should be some identifing numbers on it.
Might have to look at both.
Not sure if that is problem in my opinion. If you shut one unit off and operate other to see if it works. Then reverse to see if other operates

[12th_Man_Fan]

For the last two hours I have been trying to find a part number for the thermistor for my penguine II A/c - heat pump. Are they all the same?

I only found one on Amazon that I think will work but am not sure. It doesn't list any ac model numbers that it fits.

Are they universal or do I wait until Tuesday to call Dometic?

[dougrainer]

You are confusing what I stated. A DEFECTIVE FREEZE thermistor is what I stated. I did not state your unit was freezing up. A Bad freeze thermistor will cause the system to "think" it is freezing and will shut the compressor OFF. Now, to your thinking about why in HP mode it works fine. The FREEZE thermistor does not operate in HP mode. The evap will NOT freeze since it gets HOT in HP mode. I have a test Freeze Thermister. I install and then run the system when I suspect it is caused by a bad Thermister. Takes less than 10 minutes to do this. Doug

[12th_Man_Fan]

enblethen, thanks for your input and the tech info you have provided.

I guess a AC repairman is in my future.

This am the heat pump works perfectly with 41 degree temps. I don't understand how the compressor will run until the target temp is reached while in HP mode but will only run for a few minutes when in the ac mode.

Thanks again.