Thermostat Gremlins

[boowho]

This morning I switched on my heat pump. It came on, but after a few minutes it automatically cut out and the furnace cut in. It switched back and forth 2 or 3 times all by itself.

The display was flipping between HP and FURN about once per second.

Anyone else had this happen??

Boowho??

[tmmar]

Bill,
I have not had this happen to me.
Did you try doing a reset on the thermostat? Here's the procedure.

Make sure the thermostat is in the OFF condition.
Simultaneously press and hold the MODE and ZONE buttons.
The LCD should display “IniT” and all available zones.
Release the MODE and ZONE buttons.
Press the ON/OFF button to exit system set up.
The furnace ON/OFF temperature differential should be set at this time.

Might want to give this a try.
Tom

[boowho]

Originally Posted by tmmar

Bill,
I have not had this happen to me.
Did you try doing a reset on the thermostat? Here's the procedure.

Make sure the thermostat is in the OFF condition.
Simultaneously press and hold the MODE and ZONE buttons.
The LCD should display “IniT” and all available zones.
Release the MODE and ZONE buttons.
Press the ON/OFF button to exit system set up.
The furnace ON/OFF temperature differential should be set at this time.

Might want to give this a try.
Tom

Thanks Tom.... I WILL give it a try.

Boowho??

[gasman94]

Are you guys getting both a/c units to use the heat pump?

Rich

[tmmar]

Rich,
Only one of my a/c's is a heat pump the other is a/c only.
Tom

[gasman94]

Originally Posted by tmmar

Rich,
Only one of my a/c's is a heat pump the other is a/c only.
Tom

Thanks Tom. I thought that I read on a previous post some time ago that there was a way to turn on the heat pump to the a/c unit in the bedroom. Both units appear to be the same. They also told me at the factory that only one is operable.

[NO3putt]

Both of mine are ac and heat pump.

[tmmar]

Rich,
If you remove the grill that holds the a/c filter, if you look around you can see the model number. If you look that model number up it you should be able to see if it has heat pump ability. If it does, you would need to go up on the roof and remove the shroud. There is an aluminum covered box on the passenger side. Remove the cover and you will see a circuit board. There is a series of dip switches on the board. You need to set to the dip switch marked 'heat pump' to the 'on' position to enable the heat pump. After that is done, you would need to reboot the thermostat as I described above to recognize the units new settings.
Good luck,
Tom

[gasman94]

Thanks Tom. I also have a '14, so I probably have the same setup. I will check, however.

[Todouble]

How cold is it outside? Heat pumps are only good in these RV prob down to 35ish. It may work off an outdoor air temp sensor and below a set point auto switch to gas furnace. Just a thought. Or this could be the case and you have a faulty sensor thinking it's lower than it is and trying to switch to propane

[JTN8]

My 14 has two 15k heat pumps but I special ordered it that way, with that being said, I've used them in temps in the low 30's to high 20's and they both continued to work.

Jason

[boowho]

Originally Posted by Todouble

How cold is it outside? Heat pumps are only good in these RV prob down to 35ish. It may work off an outdoor air temp sensor and below a set point auto switch to gas furnace. Just a thought. Or this could be the case and you have a faulty sensor thinking it's lower than it is and trying to switch to propane

You may be right..... I WAS in the coldest environment I've been in since buying the coach. I will have to study up though, I did not think the whole heating system (thermo, furnace, HP) was that "smart".

Boowho??

[Todouble]

The heat pumps really can't keep up by themselves when it's 30 degrees or below outside. At this point they start staging up the electric heat strips. You may or may not have that so in your case I'm thinking it switched over to propane. This is how my home system is and I really don't know if this is your setup, just sharing my thoughts. Goodluck

[tmmar]

When I have used the heat pump in temps below about 40 it would after a while freeze up (I think) and when that happened, they compressor would cycle off until it defrosted, and then cycle back on. The gas furnace never came on by itself. It only goes on when I switch the thermostat to furnace.

[Superchief]

Same experience as Tmmar. I have found anything below 44 degrees, the heat pump doesn't put out heat and laborers.

[Witch Doctor]

Todouble is correct, when your condenser coil freezes and gets ice on it either you have a sensor on it or you have a board inside that will put it in defrost either every 30, 60 0r 90 minutes. If you do not have heat strips then it should bring on your propane furnace during the defrost cycle. The compressor will not shut off your reversing valve will switch the flow of freon to A/C but will shut off your condenser fan motor. That whats defrost the coil. I don't know what stat you have but if it has a emergency heat switch on it, that also will bring on your propane furnace. If it is working right you should see a puff of steam outside when it switches back and your Condenser fan comes back on in heat mode. Thats pretty much the basics on how they are supposed to operate. You will still feel cold air at the ceiling registers but the furnace should compensate that.

[tmmar]

gljurczyk,
The a/c's that are installed in our coaches do not have heat strips in them and the furnace does not come on during the defrost cycle. Also, the thermostat does not have an emergency heat switch. There is defrost sensor in the a/c that handles the defrosting when it ices up. This is my second Berkshire so I am very familiar with the operation of the a/c's.

[Witch Doctor]

Originally Posted by tmmar

gljurczyk,
The a/c's that are installed in our coaches do not have heat strips in them and the furnace does not come on during the defrost cycle. Also, the thermostat does not have an emergency heat switch. There is defrost sensor in the a/c that handles the defrosting when it ices up This is my second Berkshire so I am very familiar with the operation of the a/c's.

Didn't mean to ruin your day, I glad you know what the problem is then. I'm also sure you know how to trace the short. Have a nice day, hope you get it working.I was suggesting this to BOOWHO the OP, or by the way the compressor doesn't shut off during defrost mode.not quite sure what would defrost the Condenser coil if the the compressor shuts off and didn't reverse to cooling cycle as I stated. But I guess anything is possible.....

[Witch Doctor]

Boowho, If I were you I would be asking why during defrost mode your unit is not switching over to LP Furnace during your defrost cycle as tmmar has said. If you read up on the RV forum they all have auto switch over. A different stat can do that once you go into defrost. The question is why FR sets up there MH this way. they also have lock outs that are settable to say that you might not be comfortable at 35 degrees outside compared to 40 degrees lock out. To me 35 degrees ambient air temp you will not get more then 60/ 65 degree air coming into the unit. To me that is a cold draft. Hope you get your problem fixed. But just think soon you will have all summer to work on your problem good luck and happy travels.

[dalgal2014]

The overhead fans in my trailer continue to blow cold air after the lower ones have stopped blowing hot air. The thermostat is set to furnace at 60 degrees.
The trailer is almost a year old and this phenomenon started in September when I turned the temperature up to 60 expecting the system to kick on and heat the place up and then stop after the temperature had been reached.

Any ideas where to begin looking for what's wrong? Is there a sensor somewhere I need to clean?