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Robert
Robert, RV Mechanic
Category: RV
Satisfied Customers: 12792
Experience:  18 yrs. RV experience including Cummins North West, Country Coach, Monaco Coach - vendor certified.
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Heatpump.does not turn on in heat mode if thermostat.is set

Customer Question

Heatpump.does not turn on in heat mode if thermostat.is set more then 4 degrees above room temp
JA: Have you checked the coolant level? Has there been any leaking from the hoses?
Customer: No leaks I was told it was board
JA: What is the model/year of your RV?
Customer: 2001 Alfa
JA: Are you fixing your RV yourself? What have you tried so far?
Customer: Yes was working before last trip. This trip was to New Mexico in the mountains and unit was did not come on at all and did not kick on the gas unit. Temp dropped from 75 to 47 inside. So far I have just tried to get the unit to come on at higher temps
JA: Anything else you want the mechanic to know before I connect you?
Customer: Propane was turned on and all fuses check as good
Submitted: 5 months ago.
Category: RV
Expert:  Robert replied 5 months ago.

Hi my name is Robert...

DO you happen to know the make and model of the AC unit, some are designed like that, they are only meant to take the chill out of the air and will not kick on if it is more then 5 degrees off, I would like to take a look at some info if you can get me the make and model..... Robert

Expert:  Robert replied 5 months ago.

Also if you can send me a picture of the thermostat it might help as well, you should be able to add a photo into your reply using the paper clip icon...

Robert

Customer: replied 5 months ago.
6536-891 is model and a 6536-335 thermostat by RV products. The unit is designed to just take the chill out of the air n if it can't the gas unit will kick on to bring the temp up. But all it does is blow cool air n the gas does not come on. The fan runs but no heat.
Expert:  Robert replied 5 months ago.

OK

Will the furnace kick on if you select gas heat??? I get the part with the heat pump and furnace working together, I need to look into this for you some more but was wondering if the LP furnace will actually come on when selected???

Robert

Customer: replied 5 months ago.
No, propane turned on, can not see or hear gas unit fire
Expert:  Robert replied 5 months ago.

OK

Will the fan come on for the furnace? When you select gas heat and turn the temp up will the fan kick on for the furnace?

Robert

Expert:  Robert replied 5 months ago.

Trying to figure out if you have an issue with the furnace, or it is inside the AC unit, this is a basement model correct?

Robert

Customer: replied 5 months ago.
basement unit n I don't remember if the fan came on in gas mode
Customer: replied 5 months ago.
I can ck it tomorrow
Expert:  Robert replied 5 months ago.

Click HERE for a service manual on this..... IF the fan on the gas furnace is kicking on but not producing heat and you can not hear it spark then you could have an issue with the sail switch, circuit board or electrode. As the fan comes up to speed it blows on a sail switch, once the sail switch closes it sends a signal to the circuit board, once the board sees that signal the gas valve and electrode will spark, so no spark check your battery voltage, if the voltage was down a bit the fan would run but might not be enough to close the sail switch. Make sure you voltage is not under 11 volts. That would apply if the fan was coming on......

Yes you can check tomorrow, look over the manual I sent as well, pretty sure that is yours. ALSO I am fairly certain if you pop that cover off the T-stat you will find a glass fuse, pull that fuse for 10 mins and put it back inside, that should reset the thermostat.....

Let me know if you still need more help, I will try my best, ***** ***** models are always more complex.....

Robert

Expert:  Robert replied 5 months ago.

Was just checking in to see if my answer helped... IF you have more questions or concerns please feel free to contact me...

Robert

Customer: replied 5 months ago.
fan on heatpump n it comes on but blows cold air temp went down in the RV. But thermostat set on electric heat. The longer heat is on the colder it is in RV in gas mode the fan does not come on and no heat.
Expert:  Robert replied 5 months ago.

OK

Did you try pulling the fuse on the thermostat???? This could be a bad thermostat if the furnace is not kicking on. The thermostat should send a signal to the circuit board or delay relay on the furnace and the fan should kick on. SO what I would do is go to the circuit board on the furnace and see if you have voltage on the harness for the circuit board when you try to run it on gas mode. IF you have voltage present then I would have a RV shop test the board, a special board tester can be used. IF you are NOT getting voltage down at the furnace then I might try a new thermostat or have a shop diagnose more. You could have multiple issues going on and I would see if you can get the gas furnace going to start.

Also on the back of the furnace make sure there is not a breaker tripped or an on/off switch that is turned off, some have a round button for a breaker. IF you can get me the make and model of the furnace I might be able to send you a wiring diagram..... Robert