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Tcounty1 · 11-04-2018, 09:14 PM

Before we headed home a few weeks ago I wanted to try the furnace. I set the temp as low as it would go but nothing happened. No sound or anything.

Also tried to run the fridge off of gas but nothing happened there either. I know I was getting gas to it but it wouldn’t light.

Any suggestions? The ac/furnace is a Carrier.

jelag · 11-05-2018, 12:49 AM

Before we headed home a few weeks ago I wanted to try the furnace. I set the temp as low as it would go but nothing happened. No sound or anything.

When you call for heat... you have to call for a temperature that is higher than the room temperature around the thermostat... the principle is, that when a bi-metal spring gets to a set level, it bends and two contacts come together, and the furnace comes on... in your statement above if I understand you correctly you set the state LOW not High for heat... thus it won't come on....

I have a good friend that every time he parks his RV he shuts off the gas... when he goes to use the appliances he has to lite the range, and wait for the system to push out all the air in the pipes... once the range lights both the furnace, hot water heater, and refrigerator will light and work..

I tried to explain to him that he has a gas leak, and when the unit sits, the leak allows the gas in the piping to escape and he purges the lines with the range so that pure gas gets to the other appliances instead of an air/gas mix....

Of course he had it tested... but the leak is so small no one found it... yet over the time the unit sits... usually a month at a time he has this problem..

Could this be your problem..

kgburns1 · 11-05-2018, 04:40 AM

Your situation sounds like my 5er every spring when I start prepping it for travel. You didn't mention i you had been using your kitchen cook top.

After sitting all winter I can't even get the stove to light at first, so I keep the biggest burner turned on as high as it will go and keep a butane lighter next to it. It blows air for several seconds, then lights. Then I light the other burners and oven.

From that point on, everything that works on gas will work without any problems.

I know there's a leak in the system somewhere, put like the previous poster, it's so small I haven't been able to find it.

charliez · 11-05-2018, 05:27 AM

Make sure you have power to the rv. Those appliances require 12 volts to run the control. Also make sure that the gas detector is on and running correctly. if it's off or has a fault it will not let the gas flow.

Tcounty1 · 11-05-2018, 04:58 PM

Used the stove and oven all week. Still hooked up to shore power.

I meant to say I turned the thermostat up. I think it was 65 or so inside, I turned it up to 80 and nothing happened.

Randy the sly old fox · 11-05-2018, 07:38 PM

While I have not actually seen this - there could be valves between the LPG main line and the individual appliances. Make sure they are open.

On the furnace - the fan should have come on - and if there was no LPG in the pipe - it would not light and then the fan would turn off after a time out period. Most RV thermostats have to have Heat and Cool selected with a switch - just turning the thermostat up may have no effect unless the switch is set for heat.

If indeed you are not getting LPG to those appliances - you could have some kind of blockage in the lines - just like with electric or water, you just need to trace the lines and test for flow.

Tcounty1 · 11-05-2018, 08:03 PM

I know I had gas to the fridge. I loosened the line until gas came out.

Didn’t get that far along on the furnace.

charliez · 11-06-2018, 05:18 AM

Newer tanks have a leak something in them. Your fix may be as simple as turning off the tanks and turning them back on.

A question on the heater. Did it even try to do anything? Fan come on for a time and no heat? If nothing then I'd say you have 12 volt issue somewhere possibly too.

Tcounty1 · 11-06-2018, 04:58 PM

I’m going to winterize this week and I’ll try again and report back.

What about the fridge? I’m getting gas to it but it’s not trying to light.

charliez · 11-06-2018, 05:22 PM

You may not have sufficient 12 volt supply. You have to have that for the fridge to work. Also when it does light the flame will be very small and sometimes hard to see

Randy the sly old fox · 11-06-2018, 09:00 PM

I agree that the flame on the refer is small - but you can also hear it - just like a stove burner - only softer.

I am also leaning towards problems with the electric on both appliances - esp when they get gas out of the line going to the refer. Some refers will not try to re-light if it fails once - it simply lights the fault light or throws a code. Then you have to turn it off and try again.

On the furnace you could also have a loose connection in the thermostat - or the furnace - esp if it does not even run the fan as the first part of the cycle.

There have been lots of issues on new TTs with regards to appliances and faulty circuit boards - this is across all brands of RVs. Recently someone had a problem with the furnace where it came on and then turned off after a few minutes of running - turned out to be a bad thermostat interface board in the furnace. Almost any appliance with an electric spark ignition can have problems with either the electronics that control the DSI or with the propane feed - or the electronics that control it - yes there are electrically operated valves in the propane lines for the HWH, Fridge, and Furnace. The stove has good old manual valves.

There may be something to be said for standing pilot lights

Tcounty1 · 11-07-2018, 11:32 AM

My battery was hot and I was hooked to shore power. Now I may have not had 12v to the fridge idk. It works fine on shore power.

The furnace I have is Carrier unit. The thermostat is a handheld remote control.

TT is a 2005 model.

Don’t know if any of that helps

tmw188 · 11-07-2018, 04:19 PM

The remote is a t stat too? Can you operate it without the remote control?

Randy the sly old fox · 11-08-2018, 12:30 AM

The remote and the AC are Carrier and the link between them is wireless - the control board in the AC unit activates the heat cycle in the furnace. So if the furnace is not turning on at all, the problem is probably in the AC unit - which I presume works fine. From what I have read about this system on other forums is that they are a real pain because the heat sensor is in the AC in the ceiling and the unit gets confused and will run the furnace and when the heat sensor sees things getting hot it starts the AC. There is no thermostat in the remote. The furnace is all 12V so as long as there is enough power in your batteries (and LPG) it will run. Also there are batteries in the remote - are they working correctly?

I have read where some people are considering putting in a regular hard wired thermostat for the furnace and use the Carrier only for the AC.

The refer requires a heat source to boil the ammonia mixture there are two ways to source this heat - a gas flame and a 110V heater - the rest of the unit is under 12V DC control. If it runs under 120V it means that the sensors and control ckts are working fine. That leaves the sparker and the gas valve as potential problems. The sparker you can hear if you are outside and have the cover off. If you don't hear it, then you need to troubleshoot that ckt. if you hear it and there is no flame then it could be the gas valve - or the ckt that controls it. It may take two people to troubleshoot this - one on the inside running the refer and one outside watching and listening for the reaction.

I think I would be looking at getting these issues fixed before you put the TT away for the winter. Also if you find that you need to take it to a shop, they are less busy in the winter/off season.