Furnace not coming on

mdebiasi · 09-10-2018, 11:12 AM

Hello, I have a new 2019 Cherokee Wolf Pup 16BHS that I picked up in late june. During PDI the furnace did come on but now when trying to use it first time this past weekend nothing. I hear a click on the thermostat when I set temp above actual temperature but nothing happens on the heater. Is there a reset or something that I may need to do on the heater? Its a Suburban heater. I do have a reading of over -13 volts on the thermostat, which according to manual it is supposed to be a negative reading. Any helpful troubleshooting tips? is it safe to connect the red and yellow wires from the thermostat as a test to see if furnace comes on and rule out a bad thermostat?

CHICKDOE · 09-10-2018, 11:22 AM

start with the most basic.

do you have propane in the tank and is it open? do the stove burners come on? do you hear the ignitor trying to ignite in the heater? you should hear this even if the propane is off.

how far is it back to the dealer? if close is it worthwhile getting them involved?

cavie · 09-10-2018, 11:31 AM

Quote:

Originally Posted by mdebiasi

Hello, I have a new 2019 Cherokee Wolf Pup 16BHS that I picked up in late june. During PDI the furnace did come on but now when trying to use it first time this past weekend nothing. I hear a click on the thermostat when I set temp above actual temperature but nothing happens on the heater. Is there a reset or something that I may need to do on the heater? Its a Suburban heater. I do have a reading of over -13 volts on the thermostat, which according to manual it is supposed to be a negative reading. Any helpful troubleshooting tips? is it safe to connect the red and yellow wires from the thermostat as a test to see if furnace comes on and rule out a bad thermostat?

If you hear a click at the t-stat leave it alone. Be sure you have a gas supply. Check your 12-volt fuses. the fan should come on first then you should hear a click of the igniter trying to start the gas. Without the fan running nothing is gonna happen.

mdebiasi · 09-10-2018, 01:10 PM

Quote:

Originally Posted by CHICKDOE

start with the most basic.

do you have propane in the tank and is it open? do the stove burners come on? do you hear the ignitor trying to ignite in the heater? you should hear this even if the propane is off.

how far is it back to the dealer? if close is it worthwhile getting them involved?

Yes, I have propane, the stove burners come on but I don't hear the igniter trying to ignite in the heater. Dealer is 2.5hrs away so prefer to try and solving it if possible before taking it all the way back. I will check the fuses next and see.

mdebiasi · 09-10-2018, 01:15 PM

Quote:

Originally Posted by cavie

If you hear a click at the t-stat leave it alone. Be sure you have a gas supply. Check your 12-volt fuses. the fan should come on first then you should hear a click of the igniter trying to start the gas. Without the fan running nothing is gonna happen.

Fan doesn't come on. I suspect this should happen first when turning heater on. I will check the fuses next. Was wondering if there is any sort of reset in the furnace itself. I would imagine I should see voltage on the wires to heater if thermostat is on.

CHICKDOE · 09-10-2018, 01:39 PM

cavie gave the best answer. the first thing that must happen is for the fan to come on. nothing else will occur until the fan is running. yes check the fan fuse using a meter to verify that it is good. if it is then you'll probably have to trace the fan wires to see where you have power and where you lose it. the gas portion will not attempt to light if the fan is not blowing.

TimVWulp · 09-11-2018, 03:33 PM

The red wire on the thermostat is +12 volts DC. The white wire is to the furnace to give it +12 volts DC to start the furnace. The yellow wire is for starting the air conditioner.

If the furnace blower is the first step in it's startup, If it dose not start there are several possible reasons.

1 Thermostat is not putting +12 volts DC on the white wire to furnace.

2 The furnace control circuit board may have failed.

3 The air flow switch is stuck in the on position. this will not let the furnace start until it is in the off position.

mdebiasi · 09-13-2018, 11:05 AM

Hello TimVWulp, would a safe test be to connect the red and white wires on the thermostat to see if this starts the blower?

TimVWulp · 09-13-2018, 12:16 PM

Yes you can jumper the red to the white wires. The red wire should be on the R terminal and the white wire should be on the W terminal of the thermostat. You can take a jumper wire from R to W or remove the white wire from W and touch it to R terminal or red wire. be careful not to short it out as this may damage the heat anticipator in the thermostat.

**Bama Rambler** · 09-13-2018, 02:10 PM

Which A/C and thermostat do you have? If the thermostat runs both the A/C and furnace?

The thermostat might be important in figuring out where the 12 volts is coming from.

If it routes through the A/C then you could have a blown furnace fuse, but if it originates at the furnace, and you have 12 volts at the tstat, then it's not likely a blown furnace fuse.

MR.M · 09-13-2018, 03:32 PM

if the blower is not coming on and you know you have power no blown fuses . then i'll wager you have some mud dubbers nests in the combustion fan preventing the blower from spinning .

SailorSam20500 · 09-13-2018, 03:37 PM

Just a side note and probably not helpful. Back in January, on a trip down to Texas. At stop in Kentucky, furnace worked fine. Next stop, in Missouri, nothing - no heat (and it was going to -5). Fiddled with all kinds of stuff trying to get it to work without luck. Next morning - sun was out and we hit the road again and made it to Arkansas. Expected no heat, but after hooking up the power, I walked around the trailer and heard the furnace running. Temps all day were well below freezing. No idea what the issue was and it has not repeated - even my dealer took a look and found nothing.
So maybe you can fix it by taking it for a drive...

Good luck.

cavie · 09-13-2018, 03:40 PM

Quote:

Originally Posted by MR.M

if the blower is not coming on and you know you have power no blown fuses . then i'll wager you have some mud dubbers nests in the combustion fan preventing the blower from spinning .

you would lose your money. If that was the case a fuse would be blown.

mdebiasi · 09-13-2018, 04:58 PM

My thermostat is for the heater only.

**Bama Rambler** · 09-14-2018, 11:45 AM

Since it's for the furnace only it shouldn't have a relay that you could hear click.

You also said that you read voltage at the thermostat, since it gets it's power from the furnace, that means that the furnace is getting power.

mdebiasi · 09-26-2018, 01:09 PM

Quote:

Originally Posted by TimVWulp

Yes you can jumper the red to the white wires. The red wire should be on the R terminal and the white wire should be on the W terminal of the thermostat. You can take a jumper wire from R to W or remove the white wire from W and touch it to R terminal or red wire. be careful not to short it out as this may damage the heat anticipator in the thermostat.

Thanks for your advice TimVWulp... I jumpered the red to white wires on the thermostat and the fan kicked on and several seconds later the heat kicked in. So it looks like I have a faulty thermostat. I'm surprised the thermostat would go faulty off a 3 month old trailer. I will check out the price online and if cheap may not be worth the 2.5hr drive to dealer to replace or maybe replace with a better quality one.

wakeele · 02-21-2019, 04:24 PM

Now to hijack this thread a bit, I have a Wolf Pup with the Suburban furnace. First time this trip I turned it on, worked fine and got the trailer to a nice temp. Next time it came on, the fan blew for about 15, maybe 30 seconds (actually it's done both 15 and 30 second cycles), and stopped. Tried cycling it a few times, nothing. Try it every few days and still nothing. Gas burners put out nicely and the hot water heater works like a champ. Only has gotten down to about 30º at the lowest, and up to about the 50s during the day. I changed out a propane tank since the first successful lighting too. Any tips?

rockfordroo · 02-21-2019, 04:33 PM

Quote:

Originally Posted by mdebiasi

Thanks for your advice TimVWulp... I jumpered the red to white wires on the thermostat and the fan kicked on and several seconds later the heat kicked in. So it looks like I have a faulty thermostat. I'm surprised the thermostat would go faulty off a 3 month old trailer. I will check out the price online and if cheap may not be worth the 2.5hr drive to dealer to replace or maybe replace with a better quality one.

I see you've probably got the cheap Suburban T-stat. Get yourself an inexpensive battery-operated digital thermostat, something like a Honeywell RTH111 (non-programmable) or RTH211B (programmable). I replaced the Suburban T-stat like yours in my my Roo with a Honeywell RTH111. I replaced a Coleman-Mach T-stat in my Mini Lite with an RTH111.

I've attached a pic of my wiring from the Coleman Mach to the Honeywell. In your case, you've only got 2 wires. Connect one to the R connection and the other to the W connection and you should be good to go. (All the other wiring is for the A/C control, which you don't have/need.)

A digital is SO much better than the cheap analogs.

CHICKDOE · 02-21-2019, 05:21 PM

i don't see how replacing the thermostat would resolve the issue. the recommended thermostat may be better. but bottom line their job is to simply make or break a circuit t the furnace itself. it is stated that the fan comes on so the thermostat seems to be telling the furnace to come on.

it could be a couple of things but my first thought would be the sail switch. do you hear the igniter trying to spark and light the propane? knowing this would help a lot. if you do not hear any attempt to spark and light the furnace control board does is most likely getting a signal from the sail switch. the sail switch sits in the path of the airflow that the blower produces and the airflow will move the sail switch. this completes an electrical circuit and tells the control board that air is flowing and go ahead and spark / light the gas. many people have reported a stuck sail switch. i don't know how hard it is to get to it and jiggle it.

now if you hear the igniter trying to light the gas and the furnace does ot come on it is probably a gas supply problem. but since you have gas elsewhere and have tried the furnace several times this is probably not the case. turn the stove burners on again and let burn long enough to purge any possible air in the gas line and try the furnace a few more times.

rockfordroo · 02-22-2019, 10:22 AM

Quote:

Originally Posted by CHICKDOE

i don't see how replacing the thermostat would resolve the issue. the recommended thermostat may be better. but bottom line their job is to simply make or break a circuit t the furnace itself. it is stated that the fan comes on so the thermostat seems to be telling the furnace to come on.

it could be a couple of things but my first thought would be the sail switch. do you hear the igniter trying to spark and light the propane? knowing this would help a lot. if you do not hear any attempt to spark and light the furnace control board does is most likely getting a signal from the sail switch. the sail switch sits in the path of the airflow that the blower produces and the airflow will move the sail switch. this completes an electrical circuit and tells the control board that air is flowing and go ahead and spark / light the gas. many people have reported a stuck sail switch. i don't know how hard it is to get to it and jiggle it.

now if you hear the igniter trying to light the gas and the furnace does ot come on it is probably a gas supply problem. but since you have gas elsewhere and have tried the furnace several times this is probably not the case. turn the stove burners on again and let burn long enough to purge any possible air in the gas line and try the furnace a few more times.

Did you read post #16? He jumpered out the T-stat and the furnace worked.

You may also like: