Furnace problem

[muddcatt]

We have a 2012 35' Winnebago, Vista. The propane furnace will not come on. It was working fine, then suddenly, when I turned the thermostat to gas heat, nothing. It makes a click from the unit, but that is all. We flipped all the breakers, but I do not see one that says furnace, heat pumps, but no furnace. The tech at Camping World said to check the fuses. Where are they? The books we have do not show fuses. I hope this is something simple. Just hate to drive it to a service dept. when it may be something easy! Any info would be much appreciated.

[topdownman]

How cold is it? Propane won't flow at really cold temps.

[brobox]

Originally Posted by topdownman

How cold is it? Propane won't flow at really cold temps.

X2 and does the stove light? Make of furnace will also help with problem solving. That same furnace was installed in several manufactures MH's. Many may have the same brand of furnace and be able to help troubleshoot the problem.

[Clifftall]

Welcome to the forum. I've moved this to our Winnebago section hoping another member with a similar coach can assist.
Cliff

[muddcatt]

not that cold, 40's, the propane will light the stove, fridge, water heater.

[muddcatt]

Originally Posted by brobox

X2 and does the stove light? Make of furnace will also help with problem solving. That same furnace was installed in several manufactures MH's. Many may have the same brand of furnace and be able to help troubleshoot the problem.

everything else propane lights

[muddcatt]

Originally Posted by muddcatt

everything else propane lights

it is a Suburban furnace

[grtharris]

The breaker for your furnace is in the group of breakers at the All-In-One panel.
It is on the left side bottom row labeled, Front Furnace/exit fan.
I assume the fan is not running.
Check the connectors at the thermostat and furnace.

[muddcatt]

Thank you. It was not tripped. I will check the connections

[muddcatt]

Originally Posted by muddcatt

Thank you. It was not tripped. I will check the connections

The connectors look fine

[grtharris]

If you have a meter check the following at the furnace plug.
Pin 1 wire JM is GND
Pin 2 wire JJ is Call for heat from thermostat
Pin 3 wire JB is +12VDC power to furnace

If you have power on both pin 2 and 3 then it is something in the furnace.

[garykk]

Does the fan come on when you turn on the gas heat?

[TXiceman]

Originally Posted by topdownman

How cold is it? Propane won't flow at really cold temps.

Pure propane goes to atmospheric pressure (0 psig) at -40 degF. I doubt if it is that cold. If there is some moisture or oil in the regulator, it can freeze in the regulator.

If you can light the stove top burners, it is not a propane flow issue.

Your normal start sequence for a propane furnace is the blower will come on first to clear the combustion chamber. It runs for a given amount of time and if the sail switch is made, it will open the gas valve and the ignitor will fire. If a flame is detected by a temp/flame sensor, the unit will stsrt to heat. If no flame is detected, it will continue to run the fan and cycle through another ignition sequence. Normally, the furnace will try to ignite 3 times, before it locks out the gas valve. Some will let the furnace fan continue to run with no heat. To get the furnace to try igniting again, you will need to cycle the furnace off and then restart the furnace.

If your fan is not starting at all, you need to start by checking power to the furnace.

Ken

[muddcatt]

no fan..nothing

[muddcatt]

Thank you, Ken. The fan does not come on so it sounds bad connection or like you said restart...we will try these things

[ronspradley]

Originally Posted by grtharris

If you have a meter check the following at the furnace plug.
Pin 1 wire JM is GND
Pin 2 wire JJ is Call for heat from thermostat
Pin 3 wire JB is +12VDC power to furnace

If you have power on both pin 2 and 3 then it is something in the furnace.

Muddcatt, did you check as above for power?

ronspradley

[BFlinn181]

Does the wall thermostat still work to turn on air conditioner? If so, we can assume (maybe wrongly, but more later) it is sending start signal to the furnace. As TXiceman said, once the signal is sent, the fan should come on. Moving air then pushes on the sail switch which tells circuit board it's O.K. to open gas valve and ignite. If the issue is not in the thermostat or fuse to furnace 12 v power, the next thing is to suspect the fan motor. You can access the wiring through the outside hatch. Test for power here and also see if there is a switch, fuse, or circuit breaker in the access door.

RV Forced Air Furnace Outside Access Part 2 - YouTube

If you have power here, it's either the thermostat not sending a signal or a failure of the control board.

[ladagobago]

By now you know how it works but there is an off on switch (at least on mine) found on the left hand side of the furnace. It trouble shooting found on line states clearly in several areas, that the power from the thermostate go to the off on switch.

The wall thermostat controls the operation of the dual stage furnace by reacting to room temperature. This allows current to flow through the On/Off switch to the Blower Speed Control Board then to the Module Board.
How do I know this, experince on a cold autum night. Mine would not start but I tore into the unit and found this switch. it was in the on position but after I acutated the switch a few time it worked. I also believe it reset something on the board. It has worked well ever since and that was two years ago.

[jesilvas]

Unless you can check 12VDC systems then you really can't do anything. They aren't hard to learn, if you want to.
It also wouldn't heart to learn the difference between "breakers" (commonly 120VAC) and fuses (commonly 12VDC).

[skigramp]

Help me here ... can't he jumper two wires on the thermostat to see if the problem is in the furnace or in the thermostat?

I think that is possible ... but I don't know which two wires he should jumper