propane heater would not start

I've done some searching ( but not exhaustive ) here and did not find anyone with this issue. I went out to my Camper to do some work on the interior and it was in the single digits ( 8-10 deg F ) flipped the switch on the Thermostat and hit run ... the Thermostat clicked but I got no heat/no fan from the heater... I went to the stove and turned on a burner ( verifying that I had GAS ) and let that burn for 10-15 minutes to also validate constant pressure in the system. Still no heat... Gave up - went inside ( after turning everything off of course ) Move forward to today ( temp is in the high 30's F ) went to look at it and it started right up... REALLY ODD... Open to any and all ideas. Kevin

Ambient temperature related - worst one to troubleshoot.

Initial thoughts are loss of electrical connection from T-stat to control board, or control board contact separation (if there are any; I have not looked at my furnace control board). Resolved itself as temp is raised.

Might have to wait until 8-10F outside to repeat the symptom.

Sorry cannot be more help.
Brian

I agree with Brian. I'm thinking expansion/contraction of circuitry somewhere causing a bad connection. (Thermostat maybe?)

I had a television do this way back when and it turned out to be cracked solder connections on a circuit board.

When it was warm all was good, but when it would get cold , it would shrink and go open. It was a bear to find it.

Resoldered the defects and it corrected the problem.


8 degrees is not a time you want to be w/o a heater. Good luck. Trace

The thermostat operates a relay that is sometimes mounted in a control box with the living room AC. I think that relay controls power to the furnace. If the blower never started, that is something to check.

Low battery voltage could also be a culprit, especially if the power converter is not working.

If the furnace was previously running and had an improper shutdown (and was in a lockout condition - not running, but with thermostat in Heat mode), turning it off would clear the lockout.


Sent from my iPad using Tapatalk HD

danemayer said:

The thermostat operates a relay that is sometimes mounted in a control box with the living room AC. I think that relay controls power to the furnace.

Click to expand...

Great info Dan - I wondered why my AC clicked (in the ceiling) when the T-Stat called for heat. I am going to go look for that relay just so I know...... I learned one more thing today.... Thanks!

Brian

EDIT: Here is a good link Kevin that I found after exploring Dan's thought of low voltage and the implication on powering up the circuit board and high tension igniter. Volatge drop from T-Stat to limit switch to sail switch to control board. Interesting phenomenon. The link even mentions corroded connectors in these connections may contribute to voltage drop.

RV.Net Chris Bryant LP Appliances Furnaces

ok - here is another twist to this puzzle. I went back out after an hour or two and the heat was off - The Thermostat was calling for heat but the heat and blower were both off - temp was set to 65 and it was only 49 in the trailer.... I really need to get this sorted out before spring since I do camp in April when temps can get down to the 40's at night.

Turning Thermostat off and then back to heat - fires the heater again and it runs for 30 minutes - but does not seem to be putting out a huge amount of heat though the vents but it is putting out a lot of heat in the exhaust. Tomorrow I will measure the heat output temp and the exhaust temp

The Rig is on shore power and all DC voltages are at 13.2-13.5

Kevin

Sounds like maybe the propane supply is marginal. Low lp pressure can give you lukewarm air from the furnace and lockouts where there's an ignition failure and the system shuts down to protect you.

Could be tank, pigtail, regulator, auto-changeover regulator, etc. Try running off the other tank, or swap tanks and switch the auto-changeover regulator to isolate the various lp supply components.

Mine would do this same very thing. I would turn it on and off and nothing. I would go out and take the cover off the furnace then unhook the wire to the blower motor then plug it back in and boom it would work for a week or so. I am going to get it in to a dealer and get it fixed as I will need it soon as well...