Montana furnace failure

[RV Vacation]

Please use extreme caution should you decide to inspect your own furnace failure. Propane fired appliances are very safe if and when all safety features are operating as intended. Tampering with, removing or by-passing any safety features will put you, your family, and neighbors safety in jeopardy. Turn off all gas supply as well as the electrical supply. Even though your furnace may be 12 volt, chances are your ignitor will produce thousands of volts. Ever been bit by a spark plug wire?




My Montana is a 2023 3901RK.

Locate the access to your furnace. I am one of the lucky owners as my furnace access is outside behind this panel. You may need to research "YouTube How Tos" for information regarding the location of your furnace.




Remove the four screws holding the exhaust tube in place.



Remove the exhaust tube extension.



Remove the four screws holding the access panel. In my case, Keystone used a mounting flange. You might need to cut sealant around your access
panel.

If you are new to this type of work, do not panic when you see all the wiring and other fun stuff you are about to be exposed to. Do remember to check all connection points for tightness, corrosion and/or broken wires. See why you shut the electric power supply off.



Identify the "blower housing" and look for an attached switch. Again, I am lucky because I do not need to remove the entire furnace and the switch is immediately available.



Remove the wires (note which goes where) then remove the screws securing the switch to the blower housing and carefully lift the switch out and away from the housing. Be extremely careful at this point as there is a "sail" extending into the blower housing.




Inspect the point where the sail makes contact to activate the safety switch. This is where you may find debris causing the switch to fail. Gently clean the switch/sail assembly being careful not to bend or break the sail it self. Work the sail and listen for a clicking sound that will indicate the switch is operating. A continuity or multi-meter is of importance at this time as the switch can now be observed for proper operation.

If satisfied the "safety sail switch" is functioning properly replace all connections and screws as you found them.

Next locate the high limit switch found somewhere on the fire box or tube. This switch must be checked with a continuity tester or multi-meter and needs to found "normally closed". The purpose of this switch is to shut down the flame in the event the furnace overheats. Do not defeat the purpose of this switch or replace it with any switch not intended for your furnace.





Beyond these two switches you will need pull the burner and assure proper pilot/burner lighting and flame. This is where I suggest the DIYer seek professional help.

FYI, I noted during my inspection that my furnace has a "chassis ground" so if my problem persist, I will run a ground wire from the furnace back to the battery. A big problem with chassis ground is corrosion. Without a proper ground the furnace (or portions) cannot operate.

Good luck I hope this bit of information will be useful to others.

Please remember, propane appliances will be dangerous if not maintained properly. For those not experienced with this type of appliance, a few hundred dollar repair bill will be much safer for family, friends and neighbors.

Be well and safe travels.

[Carl n Susan]

The pictures are missing.

[RV Vacation]

Originally Posted by Carl n Susan

The pictures are missing.

... Addendum... I fixed it. Ask me how that went Noooo don't. lol Thanks again.
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Hello Carl-n-Susan, Yes the pictures are missing and I do apologize.

Unfortunately and all too often, this forum times out causing we slow, long winded bloggers to lose our comments by forcing us to "log in" after we attempt to submit our post.

Such is the case with the "Furnace Failure" thread. After much time and effort, I could not submit my comments/pictures without first logging back in, thus losing all the work. Having experienced this problem in the past, I copied my page, hoping to paste it after logging in for a second time. All worked well except the pictures did not paste as hoped.

To see those pictures please click on the link provided below each paragraph.

I am planning to edit the thread in hope I can add the pictures. Time is of an essence so I hope I can get that project accomplished before I might have to re-log back in.

Quite frustrating, to be honest, for a fat fingered, ratchet jawed, slow typing oldtimer.

Be well, safe travels, your friend and mine.

John

[JRTJH]

Originally Posted by RV Vacation

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...

Unfortunately and all too often, this forum times out causing we slow, long winded bloggers to lose our comments by forcing us to "log in" after we attempt to submit our post.

...

John

When you log into the forum, if you check the "Remember Me?" box directly under the block where you enter your password, that should resolve the "time out issues".

[RV Vacation]

Originally Posted by JRTJH

When you log into the forum, if you check the "Remember Me?" box directly under the block where you enter your password, that should resolve the "time out issues".

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NOW ya tell me....


Thank you JRTJH, I appreciate your advice.

[RV Vacation]

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Turns out I am not one of the lucky ones. My furnace has cast revenge upon me and the flame once again refuses to lite.

So a phone call to my dealership has a new control board and sail switch in the mail, heading my way.

Two most common problem(s) says the service manager. True to their word, and thanks to Keystones policy, I am being sent the parts directly.

FYI. Technician (when available) travel and diagnostic charges in my present area run between $180.00 and $200.00. Most warranties do not cover those charges. If parts are not immediately available you can expect additional travel charges.

Certainly I can take the RV to a dealer/repair service. Just drop your RV off and they will get to it ASAP.

Long story short I am not a happy camper regarding the furnace issue but shhhtuff happens so I find a bit of relief being able to get repair parts and/or advice sent to me directly.

Keystone's policy played a very important role with us buying our Montana.

News at 11... you guess what day.

Be well, Safe Travels, Your friend and mine;

John


Forum timed out on me again. I had to sign back in even though I was signed in. Not funny!!!

[Carl n Susan]

Originally Posted by RV Vacation

......
Forum timed out on me again. I had to sign back in even though I was signed in. Not funny!!!...

I have been signed into this forum continuously for years. I never log out. The "Remember Me" button works.

[sourdough]

I am assuming from the post that Keystone is sending you the parts under warranty and that you don't/won't take it to the dealership for service? If the parts are ordered from the dealer, you are having difficulty getting the furnace to work; why don't you tell them to have a bay ready for you when the parts arrive so they can install them then check the furnace to assure it works? A known problem with parts on hand should not mean dropping off the trailer and waiting...especially if you bought it from them.

[RV Vacation]

Originally Posted by sourdough

I am assuming from the post that Keystone is sending you the parts under warranty and that you don't/won't take it to the dealership for service? If the parts are ordered from the dealer, you are having difficulty getting the furnace to work; why don't you tell them to have a bay ready for you when the parts arrive so they can install them then check the furnace to assure it works? A known problem with parts on hand should not mean dropping off the trailer and waiting...especially if you bought it from them.

Howdy sourdough, I hope your day is going well and thank you for your question(s).


My bad and apology for not mentioning we full time travel and are presently 1069 miles from our present dealership.


Yes it is the dealership sending us the part and yes under warranty.

As for telling a repair service (dealership or not) to have a bay ready when the parts arrive.... I'm thinking you might be the recipient for an ear full of laughter. Then again, maybe not.


One selling point with buying a Keystone RV that got my attention is, "I" can get needed parts shipped directly to me (warranty or not) and "I" can have all the fun playing "replace a part" until I get the right one, and the problem is corrected. Then I can spend the "diagnostic fee" I saved, on other stuff I do not need.


PS Yes I did have to sign back in to post my response. I guess I need to type faster or take the hint and just give up.

[sourdough]

Originally Posted by RV Vacation

As for telling a repair service (dealership or not) to have a bay ready when the parts arrive.... I'm thinking you might be the recipient for an ear full of laughter. Then again, maybe not.


One selling point with buying a Keystone RV that got my attention is, "I" can get needed parts shipped directly to me (warranty or not) and "I" can have all the fun playing "replace a part" until I get the right one, and the problem is corrected. Then I can spend the "diagnostic fee" I saved, on other stuff I do not need.


PS Yes I did have to sign back in to post my response. I guess I need to type faster or take the hint and just give up.

Depending on the issue I DO request them to notify me when a bay is available for my work, the parts are on hand and it works for me. They do not laugh but I do work with them to make it easy on all of us (as I mentioned in the previous post, this is the selling dealer which you said you don't have access to). Heck, I've even had them order parts and when the parts arrive just pull in with the trailer in FRONT of a bay and they pull the tech(s) out to do the work while I wait (browse RVs, run errands, go eat etc.). It really works out better for all of us IMO. Saw you got the sign in issue fixed.

[RV Vacation]

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The parts arrived and the paper trail verified the parts were sent from Keystone to our dealership who in turn shipped the parts directly to me.

Those parts included a sail switch and a circuit board. An attached note from the service manager request that I retain the used parts and first change the sail switch then test.

Just my luck I thought, on a clear sunny 88F day, I am going to run my furnace to assure the burner will ignite each and every time the thermostat calls for heat. Wonderful!! So being the guy I am, I proceeded as requested and what do you Know, the furnace fired every time I called for heat. Not to get excited mind you because the same thing happened when I removed to inspect/test the original sail switch the first time and this new switch looks exactly like the original switch.

Anyways, hopefully our night time temps drop to the lower 60s and I can set the furnace to run at 70 ish and see how it goes.

In the meantime an email was sent to the dealership service manager explaining my situation and I would be in touch this coming Monday.

For the inquiring mind, a price tag is on each box containing a part. The switch is tagged at $33.59 and the circuit board comes in at (you may want to sit down) $238.99. [tshhh..ba dump]

The gooder news, an update on the weather shows an OAT in the mid 50's tonight and low 40s tomorrow night. I'm so happy. Will miracles never cease?

Be well, safe travels, your friend and mine.

John

[RV Vacation]

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Made it through the night with the furnace firing each and every time. Another test again tonight as our temps dip a bit lower than the 64F recorded low for last night. Pretty sure the weather dude said that temp was expected to be in the mid 50 ish degrees but oh well.

Stay tuned guys and gals it could get really exciting as the saga continues. Remember, Keystone issued the parts to my dealership who in turn sent those parts directly to me so I could make my own repair. A very important selling point for me.

[RV Vacation]

Originally Posted by RV Vacation

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Made it through the night with the furnace firing each and every time. Another test again tonight as our temps dip a bit lower than the 64F recorded low for last night. Pretty sure the weather dude said that temp was expected to be in the mid 50 ish degrees but oh well.

Stay tuned guys and gals it could get really exciting as the saga continues. Remember, Keystone issued the parts to my dealership who in turn sent those parts directly to me so I could make my own repair. A very important selling point for me.

annnnd so we ran the cooling unit to get us through the 85F day annnnnd tonight I set the thermostat for heat annnnd the blower came on annnnd ran for about a minute annnnd shut off. Two more try's and the same results sooooo WTH? Camper fans.


So I turned the thermostat off allowing more then an hour to pass before turning the thermostat back on to call for heat annnnnnd the blower came on, running better then a minute, and shut off.

I'm telling Mom!!!

Anyhow stay tuned 'cause sooner or later I will find the answer plaquing this "industry standard" of faulty and low quality appliance called a furnace being used in the RV industry.

☝ Fear not campaholics, I still have a circuit board I can replace. heh hehh, care to wish me luck?

[BethD]

We are working through this problem now. We checked all wires, switches etc. Our problem was the resettable 15A fuse located in the fuse panel. It was changed out and now the furnace is working. We have been informed that this can be changed out for a regular 15A fuse.

[RV Vacation]

Originally Posted by BethD

We are working through this problem now. We checked all wires, switches etc. Our problem was the resettable 15A fuse located in the fuse panel. It was changed out and now the furnace is working. We have been informed that this can be changed out for a regular 15A fuse.

Hello BethD welcome and thank you for responding to this thread and thankyou for providing your advice regarding the resettable fuse. I am familiar with those little rascals and while they can be convenient they can also be quite bothersome. I too carry spare fuses of the same rating to replace the resettable once I determine there is no, (or correct the) fault causing the fuse to trip.

My problem stems from the pilot light not proving thus allowing the main burner valve to open and igniting the burner. The sail switch is responsible for proving air flow through the system before allowing the pilot to prove. Any failure will cause a lockout and shut down the system including the blower.

It appears my sail switch was the culprit. Puzzling because the switch works and was opening and closing with the air flow. However, installing another switch has corrected the issue and now the furnace functions properly. I don't know but I do wonder if the contacts may have burned enough to cause enough resistance so the circuit board did not recognize the signal and fire the igniter?

Anyhow, as red faced as I may be, my most current issue has been corrected and tonight we shall put the system to test once again.

Thank you again for responding be well and safe travels.

John

[chuckster57]

Your furnace doesn’t have a pilot light. Just FYI

[RV Vacation]

Originally Posted by chuckster57

Your furnace doesn’t have a pilot light. Just FYI

Yes Chuck thank you. My furnace does not have a "standing Pilot light". Electronic igniter I think it is referred to?

Do some of you people lay awake at night waiting for someone to come along you can correct? (A/K/A; troll)

Just asking for a friend.

[RV Vacation]

Originally Posted by RV Vacation

annnnd so we ran the cooling unit to get us through the 85F day annnnnd tonight I set the thermostat for heat annnnd the blower came on annnnd ran for about a minute annnnd shut off. Two more try's and the same results sooooo WTH? Camper fans.


So I turned the thermostat off allowing more then an hour to pass before turning the thermostat back on to call for heat annnnnnd the blower came on, running better then a minute, and shut off.

I'm telling Mom!!!

Anyhow stay tuned 'cause sooner or later I will find the answer plaquing this "industry standard" of faulty and low quality appliance called a furnace being used in the RV industry.

☝ Fear not campaholics, I still have a circuit board I can replace. heh hehh, care to wish me luck?

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.OMGosh guys and gals you ain't gonna believe what I found wrong, this time, with our furnace.

Ordinarily it would not be funny but because it happened to me... yes it is.🤣 NOT!!!


So long story short [don't you wish] the original sail switch must have been the problem after all. I am not certain why the original switch failed because a continuity test revealed the switch opened and closed in conjunction with the blower motor operation. A volt meter then proved current passing through the switch when the switch closed. I did not test resistance across the closed contacts but now I do wonder if that may have been the case, thereby preventing the proper signal reaching the circuit board and not allowing the igniter to fire? What do you think out there my Tech friends? Inquiring minds want to know.

Anyhow my dilemma of another misfire lockout turned out to be a valve known to MoHo owners as an "Extend A Stay" propane valve. This valve allows the connection of an external propane tank via a hose. The valve also allows devices such as grills and griddles to be fed from the on board MoHo propane supply.

OK now to set the stage before the speculations fly. We have been operating with our auto change over control set to our left propane tank since before the furnace malfunction has begun. The "Extend A Stay" valve is connected to the right tank supply line. [que Jeparody theme song]

Ok now that the experts have had time to digest the information. The "Extend A Stay" is said to have a safety feature that will automatically shut the valve off in the event of a substantial pressure loss. [que theme song] ... annnnd apparently when the left tank exhausted it's supply the auto change over valve switched to the right full propane tank. My guess is the change over occurred while the furnace burner was ignited creating a sudden pressure drop across the supply line fooling the "Extend A Valve" into thinking there was a propane leak and the rest is history. Maybe even, the hot water heater was burning at the same time.

Speaking of the hot water tank, that is how I found the propane had been shut off. No hot water this morning with the hot water burner in "lock out" Of course my first suspect was the auto change over valve malfunctioned but such is not he case. Removal of the "Extend A Stay" and we are back in business with hot water and a furnace ready and waiting to keep us toasty warm on those cool winter nights. Which, is suppose to happen to night with the temps dropping in to the mid 40's.

Speaking of winter, how exciting with Thanksgiving next week and the smell of roast turkey in the oven along with pumpkin pie and cookies too. I can not wait.

Speaking of not waiting, raise your hand, out there, if can no longer wait for me to shut up. Great than, your wish is my command.

Be well, safe travels and in case I do not see you again [🤣 don't you wish] HAPPY THANKS GIVING EVERYONE. he hee unless you are a turkey. 🦃

[chuckster57]

Originally Posted by RV Vacation

Yes Chuck thank you. My furnace does not have a "standing Pilot light". Electronic igniter I think it is referred to?

Do some of you people lay awake at night waiting for someone to come along you can correct? (A/K/A; troll)

Just asking for a friend.

As a member and RV tech, I simply try to correct mis information. I’m thinking you’re calling me a troll, and that is in direct violation of site rules. Please see your PMs.

[firestation12]

Originally Posted by chuckster57

As a member and RV tech, I simply try to correct mis information. I’m thinking you’re calling me a troll, and that is in direct violation of site rules. Please see your PMs.

Hard to say if you were being referred to as a troll. After reading OP’s reactive responses to others comments on another post titled “air lift system X vs Y” started on 11-17-2023, then maybe.