2022 Keystone Pathfinder Furnace No Ignite

[rosco]

Brand new 4 month old keystone pathfinder furnace stopped working was fine, but noticed did not turn on last night and will not ignite. Blower comes on then shuts off. Propane tanks are 1/2 full+. Saw older posts regarding dust and sensors. I can access from outside. Can't locate panel with light? that may need to be reset. Any help appreciated.

[JRTJH]

Originally Posted by rosco

Brand new 4 month old keystone pathfinder furnace stopped working was fine, but noticed did not turn on last night and will not ignite. Blower comes on then shuts off. Propane tanks are 1/2 full+. Saw older posts regarding dust and sensors. I can access from outside. Can't locate panel with light? that may need to be reset. Any help appreciated.

Keystone doesn't build the Pathfinder. Coachman, a division of Forest River RV's is the manufacturer.

That said, all the RV manufacturers use the same two brands of furnace, but some of the thermostats and how the furnace and air conditioner interface may be slightly different.

What brand and model RV furnace and thermostat does your Forest River Coachman Pathfinder have in it ???

[rosco]

furnace=Dometic unsure model the book offers many. I did the turn on range burners on off several times. the thermostat=GE single zone model RARMC2A2

[sourdough]

Can you get to the furnace from the exterior to get the make/model number? What is the model number of your trailer? Look for an exhaust port on the outside. Hopefully it has a the panel you can remove. Here's a link to an Atwood (now Dometic) furnace;

https://www.google.com/search?q=how+...id:0t8vRuGdZLw

[LHaven]

Simple diagnostic:
When you call for heat on a working furnace, you should hear the following, in order:
A click from the interface box (usually inside the A/C)
Furnace fan start up
(After five seconds or so of fan) one or more sharp snaps/clicks from the piezo igniter
A whoosh from the propane igniting.

So you got to the fan. Do you hear the snaps? I'm presuming you don't hear the whoosh. Answers help narrow the possible failure mode down.

[rosco]

I know the sounds when worked correctly. Now you don't hear the combustion and its loud outside when operating correctly.

[rosco]

model CU826A year 21 tried to send a jpg but not techy enough, there is an access panel from outside

[jsb5717]

If you have outside access then the easiest thing to check first is the sail switch. The sail switch must engage in order for the furnace to engage the next step of propane flow and ignition as outlined above. It's possible that the sail switch just has some lint caught in it. Pull it and make sure it's clean. If that doesn't work then the switch might be bad (you can check the switch with a multimeter to see if it's working as well). It could be other things that require more entailed diagnosis but that's where I'd start.

[rosco]

thanks could you tell me what looks like and best place to find.

[jsb5717]

Originally Posted by rosco

thanks could you tell me what looks like and best place to find.

On the Atwood (Dometic) it typically has 3 blue wires attached to it and it mounts to the case of the squirrel cage fan. You can also try jumping the blue wires at the switch, bypassing the switch, and try running the furnace to see if it tries to ignite.

There are YouTube videos on this, and other furnace issues, that would be helpful for you to get a visual of what things look like and where they're located.

[rosco]

thanks so much I have the schematic and will begin the process. I'll keep you posted with my findings

[rosco]

so, I thought I had access from outside but realize that is the backside of refridge. So inside under the refrig is access to furnace and it appears the furnace will need to be removed to access the sail switch.

So, unsure if I want to tackle that as the trailer is only a few months old even though made in 2022 (they bought many of the model) and if I mess up its on me. Problem is we are living in rv as home being built. I watched a video about removing unit from a different model but similiar. Looks like wires ducts and the gas line. If anyone removed furnance from inside have any tips or suggestions?

[jsb5717]

I’ve removed furnaces many times. it’s really all about how handy you are and confidence to do the work safely. If the rig is still under warranty I would start by contacting the dealer. See if they can help provide a solution since you’re living in the rig.

[rosco]

Thanks to all that reached out with suggestions. Yes, it is under warranty and therefore, will make arrangements to get it there. Again, thanks so much for the suggestions.!!!

[LHaven]

Originally Posted by rosco

So inside under the refrig is access to furnace
Looks like wires ducts and the gas line. If anyone removed furnance from inside have any tips or suggestions?

I had a mobile tech do mine because it looked like a scary job, plus working at floor level is a problem for me. But when I saw it done, it was way easier than I had expected.

First off, the unit is way lighter than it looks. Almost like it's hollow. The biggest issue with physically getting it in or out is not to scar the woodwork, otherwise, it's barely any effort.

One fear was that I would have to screw with hose clamps or similar at arm's length, but the ductwork is right up front, on disc connectors, that just rotate about 20° CCW and then pop off. You push them barely into the floor opening to get them out of the way of the removal.

There are four wires -- two power and two thermostat. Take photos and mark them, nothing complicated. Tape the +12 lead against shorting.

The only really crucial part is disconnecting and reconnecting the propane joint. Have a matching gas plug handy if you need to run propane for other appliances while the heater is removed.

There is one floor screw at each corner, and easier to reach the back ones than I feared. Also, there is an exhaust port that runs outdoors, it just pulls apart but you will have to mate it properly on replacement. If it's difficult, just unscrew the outdoor vent and mate it from outside when the furnace is done.

[oldnjrver]

Check out the combustion tube.. We had about 6 or 8 stink bugs in the air mix tube that kept our furnace from firing off...
Safe travels and all the best.

[drycamper]

Kinda just skimmed this thread and didn't see anything about 12vt. power supply. If running trailer on batteries without shore power, the sail switch will not activate under a certain voltage. The experts can add to this. I experienced this many years ago.

[LHaven]

Originally Posted by drycamper

If running trailer on batteries without shore power, the sail switch will not activate under a certain voltage.

Sounds perfectly reasonable, if there's not enough battery to get the fan up to sufficient speed.

[Bry69]

I had the exact same issue the first time I tried my heater out. The cause? I had accidentally placed something on my deck, directly over the outside inlet/exhaust outlets ("hello McFly" moment for sure). Basically it's a safety catch preventing potential fires/carbon monoxide poisoning. So just rule out this simple oversight first and make sure these outside ports are obstruction- free.

[RV Vacation]

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A funny thing happened on my way to the RV resort... ermmm OK it happened 'after' we arrived at the RV resort but it did happen. The furnace in our 2023 Montana stopped working. Imagine that!! Who Knew??

At first, the furnace would shut down but after resetting, the burner would fire and run just dandy fine. So, I'm thinking maybe just some air in the line, but alas, the furnace finally stopped producing heat.

Same symptoms, blower starts but no click.. click.. whoosh as been so evident these past cold nights. for electric heaters.

Thanks for the input and ideas, I for one, appreciate all the good folks taking their time trying to lend a helping hand.

So long story short (like that's possible with me) I sit here at 6:00 AM, sipping coffee, waiting for the sun to come over the tree tops and the magic hour of "you can make noise in the RV park" before I attempt to destroy a once perfectly good heating system.

Two points I find exceptionally interesting are the "battery voltage" and the "stinkbug(s)" interfering with the sail switch. My battery or I should say the RV battery is at 13.2 volts so I think I can rule that problem out, but the "stinkbug(s)" will require further investigation.

Stay tuned news at 11:00...

Be well, safe travels, your friend and mine,

John