Gas furnace not lighting....

[bbusbee]

I can hear the RVComfort.hp thermostat click to light the furnace but the furnace does not light. I have two bottles partially full, one about 2/3 full and the other almost empty. I have tried switching bottles but does not help yet I can use the propane stove top so I know gas if flowing through the system.
Is there an igniter that lights the furnace that could be defective and can I trouble shoot bypassing this device to prove the defect?
2013 38' Redwood.

[r time soon]

The Suburban LP furnace does indeed have an igniter board. You state that the furnace fails to light. Does the furnace spin up and spin the squirrel cages inside? What condition are your battery(ies) in? Are you on shore power? The furnace should spin up and do a series of tests. If the fan doesn't spin fast enough ( indicative of low voltage) to engage a sail switch ( basically a microswitch with a small piece of metal on an arm to engage the switch) the furnace won't light for safety reasons. If you can't hear the furnace fan spin up then that is a different problem altogether. Possibly the 15 amp fuse for the furnace might be blown. Check in your distribution panel for blown fuse. A blown fuse won't always show the red light to indicate when a fuse is blown. A load is needed for the current to pass to the triode to make the red light turn on. Check things further and let us know what is going on. More information should help.

[Goat]

Do an internet search for " rv furnace troubleshooting Gary rv roamer" Gary has written the most straightforward document to troubleshoot an RV furnace.

[r time soon]

Would also suggest downloading the Suburban Furnace Manual. Covers most models and has troubleshooting details inside.


https://www.google.com/url?sa=t&rct=...Z3-_52-9YCn6rf

[bbusbee]

You guys are great, will do for sure.

[bbusbee]

Originally Posted by r time soon

The Suburban LP furnace does indeed have an igniter board. You state that the furnace fails to light. Does the furnace spin up and spin the squirrel cages inside? What condition are your battery(ies) in? Are you on shore power? The furnace should spin up and do a series of tests. If the fan doesn't spin fast enough ( indicative of low voltage) to engage a sail switch ( basically a microswitch with a small piece of metal on an arm to engage the switch) the furnace won't light for safety reasons. If you can't hear the furnace fan spin up then that is a different problem altogether. Possibly the 15 amp fuse for the furnace might be blown. Check in your distribution panel for blown fuse. A blown fuse won't always show the red light to indicate when a fuse is blown. A load is needed for the current to pass to the triode to make the red light turn on. Check things further and let us know what is going on. More information should help.

I don't hear anything other than the click which is not very loud. In the past when I heard the click it would be followed by the lighting of the furnace immediately, now I just hear the click and nothing.
We have been connected to shore power for months and so I don't think the batteries come into play now.
I did find a blown 15amp fuse and replaced it with the hallway fuse just to see if it helped, no luck. it was #14 in the fuse panel, see the attached image.

[r time soon]

Still don't know if the furnace is spinning or not. Do you have someone there with you that could stand outside the furnace area to listen for and feel if the exhaust on the furnace is blowing air or not when you switch the thermostat to heat at a temperature setting that would call for heat to come on? By stating it is not lighting doesn't help much.

[almcc]

If you get a click at the stat and the furnace isn't doing anything you probably have a bad main board at the furnace. I've gone through 2 main boards on our 2013 RL's furnace, the board is mounted on a bracket that screws to the furnace fan cover. You can install a replacement but it has tight wires connected to the board (I watched the tech replacing the first one), Amazon has a replacement board that's supposed to be better than the OEM one, that's what I put in last time.

[bbusbee]

ALMCC can you provide a link to the Amazon replacement? Does the entire furnace need to be pulled out to replace the board?

[bbusbee]

Rtime soon, the furnace is doing nothing when operating on gas, there is no fan running or anything other than the click I hear.

[almcc]

Originally Posted by bbusbee

ALMCC can you provide a link to the Amazon replacement? Does the entire furnace need to be pulled out to replace the board?

As indicated above, the wires are tight (particularly the blue single wire from memory, not the other multiple ones attached to a connector). The tech extended the wire with a crimp connector and wire to enable him to remove/install the new board. If you look at the furnace from the outside after removing the cover you will see a sheet metal piece attached to the fan cover with 2 screws, the board is mounted on that piece. You don't have to take the furnace out to get to it. Be sure to cut all power first.


The Amazon link is below, no pricing because I'm in Canada looking at the US site, you should be able to get full info if you are in the US. https://www.amazon.com/Suburban-SB52...6965804&sr=8-1

[r time soon]

If the fan doesn't come on you still might have a 12 volt issue. Or it could be the circuit board. Do you own a multimeter? Can you access the furnace to check for 12 volts at the furnace? You will probably need to remove a panel in your basement in order to get to the furnace, either to check for power or to work on the furnace.

[Goat]

I know this isn't going to sound good, but please understand I'm not trying to be ignorant or mean. The typed word just doesn't come out the way it should. If you don't have a multimeter, get a decent one, and learn how to use it. Something I've never understood is throwing parts at something, rather than troubleshooting the issue correctly. I posted how to get the best furnace troubleshooting guide out there. Pretty straightforward and pretty much better than the factory manual.
I'm not sure about the board in the link, but Dinosaur boards are about the best. No, I'm not affiliated with them.

[bbusbee]

Thanks Goat, yes I have a good multimeter and yes I know how to use it but I always prefer to ask for advice and suggestions before I start digging into myself. Thanks for the input.

[almcc]

Originally Posted by bbusbee

Thanks Goat, yes I have a good multimeter and yes I know how to use it but I always prefer to ask for advice and suggestions before I start digging into myself. Thanks for the input.

Just a final comment, if the fuse that blew was the one for the furnace some tracing with a meter might be in order but the board failure is a common issue, as indicated I have lost 2, I helped our neighbour in a similar vintage Redwood replace the board last winter and my other friend with a Redwood had to replace the board as well. I'm betting that's what you will find as well.

[piper guy]

One last comment, pull the fuse for the thermostat hen working on the board. Otherwise it will blow as you’re removing or installing boards. And yes, I’ve lost one and now keep a spare. Common problem.

[bbusbee]

Originally Posted by piper guy

One last comment, pull the fuse for the thermostat hen working on the board. Otherwise it will blow as you’re removing or installing boards. And yes, I’ve lost one and now keep a spare. Common problem.

I assume this fuse is located on the board easily seen? Got a picture by any chance?

[bbusbee]

You guys are awesome!! Thank you for all your help, I will get on i soon.

Regards,
BBusbee

[almcc]

It may be just as easy to kill the 12V power by throwing the switch near the batteries, and pull the 110V power. The check is that the tsat should be blank after the power is turned off. BTW, the stat defaults to 72F when the power is turned back on.

[r time soon]

The attached picture should give you an idea of the fuse location. Yours should be similar to this one.