House thermostat not responding

[weatherbear]

Hi. I have a 2016 Thor axis 24.1. After some heavy rain and wind, I heard a rapid clicking sound in the area around the furnace. AC was running at the time. I turned it off with the thermostat and ran the furnace fan and the clicking stopped. When the fan stopped the clicking started again. I removed furnace cover and there was quite a bit of water inside. I removed the water and dried any contacts I could reach and the clicking stopped. However, when I tried to start the AC back up there was no response from thermostat. I was also unable to start furnace. Power is on elsewhere, along with house batteries. Not a click from the slidebar in either location, AC, heat, and no fan. Thermostat seems dead for some reason. Checked house fuse box, all were fine, though none were marked as thermostat. There are no batteries in it. ANY THOUGHTS? Is the even a house thermostat fuse, and if so is it located somewhere else? Fuse on AC and furnace is fine, seems to just be a thermostat issue to me.

Thanks fellow travelers!!

Dan

[Beau388]

Originally Posted by weatherbear

Hi. I have a 2016 Thor axis 24.1. After some heavy rain and wind, I heard a rapid clicking sound in the area around the furnace. AC was running at the time. I turned it off with the thermostat and ran the furnace fan and the clicking stopped. When the fan stopped the clicking started again. I removed furnace cover and there was quite a bit of water inside. I removed the water and dried any contacts I could reach and the clicking stopped. However, when I tried to start the AC back up there was no response from thermostat. I was also unable to start furnace. Power is on elsewhere, along with house batteries. Not a click from the slidebar in either location, AC, heat, and no fan. Thermostat seems dead for some reason. Checked house fuse box, all were fine, though none were marked as thermostat. There are no batteries in it. ANY THOUGHTS? Is the even a house thermostat fuse, and if so is it located somewhere else? Fuse on AC and furnace is fine, seems to just be a thermostat issue to me.

Thanks fellow travelers!!

Dan

Your thermostat is powered by 12 volt power coming from the propane furnace. If the furnace has a problem the thermostat has no power and the roof A/C won't work. When the furnace circuit board gets wet with power on it usually needs to be replaced.

[weatherbear]

Originally Posted by Beau388

Your thermostat is powered by 12 volt power coming from the propane furnace. If the furnace has a problem the thermostat has no power and the roof A/C won't work. When the furnace circuit board gets wet with power on it usually needs to be replaced.

Ok…thanks a million! Seems a bit odd to draw power from a spot that potential could get wet though. Any idea why they do that?


Dan

[16ACE27]

Originally Posted by weatherbear

Ok…thanks a million! Seems a bit odd to draw power from a spot that potential could get wet though. Any idea why they do that?


Dan

It's not suppose to get wet.

An RV thermostat needs 12 VDC to operate. Best place to get it is from an appliance that it controls that also has 12 VDC run to it. You're already running wires to the furnace so what's another one in the cable bundle.

[weatherbear]

Originally Posted by 16ACE27

It's not suppose to get wet.

An RV thermostat needs 12 VDC to operate. Best place to get it is from an appliance that it controls that also has 12 VDC run to it. You're already running wires to the furnace so what's another one in the cable bundle.

I hear ya. I pulled out and looked at the circuit board, couldn’t find anything that looks wrong. Pulled out every connector and tried to dry things out. Any idea which one would be power to the thermostat? Also, what do you think the loud clicking sound was when it got wet in there?

Thanks…Dan

[16ACE27]

Originally Posted by weatherbear

I hear ya. I pulled out and looked at the circuit board, couldn’t find anything that looks wrong. Pulled out every connector and tried to dry things out. Any idea which one would be power to the thermostat? Also, what do you think the loud clicking sound was when it got wet in there?

Thanks…Dan

You have a RESET/OFF/ON switch on the furnace. One side is +12 VDC supply. The other side goes to the furnace through the circuit board connector AND to the thermostat.



The clicking was probably the blower relay.

[weatherbear]

Originally Posted by 16ACE27

You have a RESET/OFF/ON switch on the furnace. One side is +12 VDC supply. The other side goes to the furnace through the circuit board connector AND to the thermostat.



The clicking was probably the blower relay.

Thanks! Wish I were better at reading schematics. 😳 Would the reset switch be accessible from the outside door, ie where the circuit board and blower motor and igniter are, or from another access point inside the RV?

Thanks again…

Dan

[Jimbo56]

Originally Posted by weatherbear

I hear ya. I pulled out and looked at the circuit board, couldn’t find anything that looks wrong. Pulled out every connector and tried to dry things out. Any idea which one would be power to the thermostat? Also, what do you think the loud clicking sound was when it got wet in there?

Thanks…Dan

Have you checked the 12v fuse marked appliance. It runs the thermostat.

[weatherbear]

Originally Posted by Jimbo56

Have you checked the 12v fuse marked appliance. It runs the thermostat.

I actually have a 15 amp fuse marked appliances. I checked and it looks good, as do all my other fuses. No red light, and connection intact. Guess I can double-check and maybe replace it anyway.

Thanks…

Dan

[16ACE27]

Originally Posted by weatherbear

Thanks! Wish I were better at reading schematics. 😳 Would the reset switch be accessible from the outside door, ie where the circuit board and blower motor and igniter are, or from another access point inside the RV?

Thanks again…

Dan

From the outside door:

[weatherbear]

Originally Posted by 16ACE27

From the outside door:

OMG the switch reset actually worked! You sir, are a lifesaver. I was just about to order a new circuit board. I so want to have your baby! 🤗😂

Thank you for solving my issue, much appreciated!

Dan

[Richard]

16ace27 knows his stuff…. Have always found his comments and advice to be very helpful.

You will come to love wet conditions and furnace circuit boards!