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sixkilo · 01-04-2016, 08:49 PM

While prepping for colder weather I decided to run the furnace for a few moments. I also attempted to start heat pump. Unit ran for about three seconds and shut down. Thermostat went blank. I jiggled fuse at control and got power back but no response from either furnace or heat pump. I have checked circuit breaker, fuse, LP. It is a Suburban system. Any ideas? Thanks

Mr_D · 01-04-2016, 09:00 PM

What's the outside temperature? When it gets down to 40° or so most quit and switch over to the furnace.

CampDaven · 01-04-2016, 09:42 PM

Heap pump runs on 110, either via battery/inverter or pedestal A/C. Furnace runs on DC. Do you have all other power running okay, lights on DC and 110 for TV?
If so, there may be a thermostat reset function. Check your manuals.

sixkilo · 01-05-2016, 07:05 AM

Suburban 30 SF. 2002 Winnie. Temps were in the 30's at the time. Shore power on. Batteries great. I had used the furnace earlier in the week. I decided to test the heat pump and slid control switch to electric. The pump started for just a second or two then quit. Thermostat went blank. I have jiggled the 2amp fuse at thermo and replaced fuse in house circuit as well as flipped AC breaker. The fan will not come on either. I fired up the cooktop and it ran blue. I cannot test water heater as I have bypassed it and pinked everything else. At some point I will give it an audio test with DW.

kkeever · 01-05-2016, 07:11 AM

Propane furnaces have a lock out feature that requires the thermostat to not call for heat momentarily, however, if there is no power to the thermostat the furnace will not operate.

Outside temperatures in the thirties will cause the heat pump to lock out also.

sixkilo · 01-05-2016, 07:46 AM

How do I overide lockout?

AFChap · 01-05-2016, 07:52 AM

BOTH the lp furnace and the heat pump require 12v power at the t-stat to operate. Sounds like a t- stat problem. As you found, there is a fuse in the stat. If nothing else, the stat itself can be bad. I had to replace mine.

sixkilo · 01-05-2016, 08:23 AM

Thermostat (Coleman Comfort Mach series) shows house temp but once doesn't respond to even Fan on slide. How would I check inverter? Thanks

TonyMac · 01-05-2016, 08:35 AM

Quote:

Originally Posted by sixkilo

How do I overide lockout?

I don't think you can override the heat pump's temperature lockout, and I don't think you want to. There is not enough heat in 30 degree outside air for the heat pump to work.

AFChap · 01-05-2016, 08:59 AM

Check inverter for what? It takes in 12v and puts out 120v. T-stat runs on 12v, and sends calls for heat/cooling via 12v. The heat pump requires 120v shore power to operate. It will not run on inverter, not even the blower. The lp furnace is powered by 12v. If the t-stat won't attempt to start the lp furnace, either the t-stat is faulty or there is a problem at the furnace control board.

sixkilo · 01-05-2016, 10:27 AM

I had read on various threads about the converter/inverter not giving enough juice to furnace. Apparently there also can be a relationship to the propane regulator as well. So I am trying to cover all the bases.

DancinCampers · 01-06-2016, 01:20 PM

Slide switch to cool, and see if basement unit comes on.

When you put switch to gas heat, wiggle it a little to see if lp furnace will come on.

tderonne · 01-06-2016, 01:24 PM

Quote:

Originally Posted by DancinCampers

Slide switch to cool, and see if basement unit comes on.

When you put switch to gas heat, wiggle it a little to see if lp furnace will come on.

+1 on this. The slider switch is a weak point in the thermostats.

sixkilo · 01-07-2016, 06:48 AM

I did just as you both suggested. Yes AC fan runs now as well as fan but not blower. I checked cleanliness of furnace and found no debris. Jiggled the sail and wiring etc. I will go get a clampon amp meter today. Meanwhile, I disassembled the thermo slide switch inadvertently(ie: it came apart as I was examining it)!! I got it back together but there is quite a bit of wear on the circuit tabs. While I was deciding what to do next the furnace came on and ran for a couple of minutes then shut down. It was late and cold outside so I am waiting for temps to improve(chortle,chortle) at which time I will employ the amp meter. Thanks everyone.