Heater Fan

[Jerry B.]

Went out to my 2017 Vegas this morning and heard a strange noise coming from behind the heater exhaust panel. Opened the access panel and it was the fan running. The heater has not been run in several months. What could have turned the fan on?? There is an “on” “off” switch at the fan. It was in the “on” position. I turned it off and the fan stopped I then switched it to “on” the fan did not come on. I think the Thor boogie man has visited [emoji23] Any help appreciated.

[16ACE27]

Which on/off switch are you talking about?
The one on the furnace?
Or the one on the thermostat?

The furnace control board may have gotten wet and energized the fan relay which stuck until you removed power by turning the furnace reset switch to OFF.

[MLP]

Don't adjust your glasses and do not touch your controls. You have entered the "Twilight Zone". I don't worry about a one time occurrence so long as I cannot easily repeat it. Second time, I want to hunt it down.

[abjbrtd]

Originally Posted by 16ACE27

Which on/off switch are you talking about?
The one on the furnace?
Or the one on the thermostat?

The furnace control board may have gotten wet and energized the fan relay which stuck until you removed power by turning the furnace reset switch to OFF.

99.9% sure this is what happened, it'll happen again and might not clear when you use the on/off switch.
Time to get some contact cleaner available at any autosupply, Walmart or Amazon.

The little circuit board is easy to get out and clean.
Use the on/off switch, unplug the wire plug and turn it over, you'll probably see what looks like rust. Use the contact cleaner on both sides and the cable and connector on the board. It'll be dry by the time you get it reinstalled, don't forget the cable and switch.
Good luck

Here's a link for a replacement board.
https://www.dinosaurelectronics.com/

[Chateau_Nomad]

Originally Posted by abjbrtd

99.9% sure this is what happened, it'll happen again and might not clear when you use the on/off switch.
Time to get some contact cleaner available at any autosupply, Walmart or Amazon.

The little circuit board is easy to get out and clean.
Use the on/off switch, unplug the wire plug and turn it over, you'll probably see what looks like rust. Use the contact cleaner on both sides and the cable and connector on the board. It'll be dry by the time you get it reinstalled, don't forget the cable and switch.
Good luck

Here's a link for a replacement board.
https://www.dinosaurelectronics.com/

I was exercising the generator last week, and when I shut down the genny I noticed the furnace fan was running... thermostat was OFF. ???

I turned the battery disconnect switch OFF and the furnace fan stopped (of course - expected).

I chalked it up as an anomaly, but now I'm thinking the same thing happened here as the OP.

Is the board easily accessible from the outside panel? And the switch?

[kwplot34]

Originally Posted by Chateau_Nomad

I was exercising the generator last week, and when I shut down the genny I noticed the furnace fan was running... thermostat was OFF. ???

I turned the battery disconnect switch OFF and the furnace fan stopped (of course - expected).

I chalked it up as an anomaly, but now I'm thinking the same thing happened here as the OP.

Is the board easily accessible from the outside panel? And the switch?

Yes the board is right there when you pull the outside panel off and so is the ON/OFF switch.
I had this same issue with the 31L we had, I pulled the board out and encapsulated it in an electrical epoxy, no more issues after that.

[Chateau_Nomad]

Originally Posted by kwplot34

Yes the board is right there when you pull the outside panel off and so is the ON/OFF switch.
I had this same issue with the 31L we had, I pulled the board out and encapsulated it in an electrical epoxy, no more issues after that.

Thanks! Checking when the rain stops here...

If it's still in good shape, I plan to apply some sort of conformal coating to seal it. Gotta love exposed circuit boards!

[RJBlanton]

I have had this happen twice, both time after I had the RV washed. I finally figured out water had gotten in to the exterior furnace vent . The fan finally quit after quite a few hours.

[Bill Johnson]

Originally Posted by Jerry B.

Went out to my 2017 Vegas this morning and heard a strange noise coming from behind the heater exhaust panel. Opened the access panel and it was the fan running. The heater has not been run in several months. What could have turned the fan on?? There is an “on” “off” switch at the fan. It was in the “on” position. I turned it off and the fan stopped I then switched it to “on” the fan did not come on. I think the Thor boogie man has visited [emoji23] Any help appreciated.

Yes it's abnormal but isn't the power disconnect off when your not using it?

[Bill Johnson]

Originally Posted by Jerry B.

Went out to my 2017 Vegas this morning and heard a strange noise coming from behind the heater exhaust panel. Opened the access panel and it was the fan running. The heater has not been run in several months. What could have turned the fan on?? There is an “on” “off” switch at the fan. It was in the “on” position. I turned it off and the fan stopped I then switched it to “on” the fan did not come on. I think the Thor boogie man has visited [emoji23] Any help appreciated.

Amazon sells conformal silicone coating for circuit boards