Water Heater Troubleshooting

[michaelkoss]

Hello, all! Yet another water heater thread. I've been searching the forum and trying a number of things with no luck.


I have a 2019 Thor Four Winds. The LP water heater does not work. Whenever I flip the switch for LP, I can hear the tank outside click three times with about 30 seconds between each. I can also slightly smell LP when standing outside. After the third click, the FLT (I think that means "fault") light comes on inside the RV. If I use the 110V heater, it works.


Reading other threads, I have seen and tried:


- burning all three stove burners for 5 minutes and trying again
- blowing out the burner tube and burner chamber with compressed air
- checked the fuse on the heater
- turned off the propane at the tank and slowly opened it again
- emptied the tank and filled it with water again
- checked to be sure all the faucets were off



I have attached an image of the heater diagramming where I blew out.



I am at a complete loss! Please help!

[javelin]

Welcome to the forum. What you are describing is the typical start sequence for the propane portion of the typical Atwood (now owned by Dometic) water heater. It attempts to start three times and if no ignition, the unit goes into lockout mode and turns on the red light at the control switch inside your coach. To retry the start sequence you turn off the control switch and turn it back on (they advise waiting a few minutes for any propane to dissapate for safety reasons). The fact the start sequence made it this far (sparking and you smell some gas) suggests that your fuses and thermal devices are probably OK. That leaves a gas, gas valve or ignition problem. For such a new coach combustion components “probably” are not very dirty, but spiders can get into the propane burner tube and gas oriface and may require clean out (there are videos on You Tube for many troubleshooting procedures). The gas oriface should be handled carefully - no metal reaming etc for cleaning it. There also can be spark gap issues with the spark electrodes/flame sensor......and the most expensive issue can be the control board itself has failed in some way. Many swear by replacing with a correct replacement board made by Dinosaur Boards on line. If you are under warranty, you might want to advise Thor/call Dometic for assistance or just take it back to your Dealer.......or see if they will spring for a Mobile tech repair with reimbursement to you for the repair if your Dealer is hours away. Last suggestion is the manual for the water heater should have good descriptions of operation and troubleshooting tips.

[16ACE27]

Has it ever worked on propane? Or is this a new problem?

Turn it on and run out to the water heater. The clicking should be coming from the ignitor in your RH blow out arrow. That is multiple clicking like "click, click, click, click, click..........." in 3 cycles. If all you hear is a single click (3 times before lockout) from the solenoid to the left of your LH blowout arrow then you are not getting spark ignition, but the propane valve is opening correctly.

No sparking can be due to:

Faulty ignitor
Mis-aligned ignitor
Crap shorting out the ignitor probes
Faulty control board.

Take the ignitor out an check it out. Should be about a 1/4" gap between the probes with no spider webs between them. Check the wire connections between the control board and the ignitor for looseness and corrosion.

if still no sparking, replace the ignitor.
If still no sparking you now have a spare ignitor and replacing the control board is next.

Good luck and keep us informed on your progress.

[michaelkoss]

Thank you both for your replies! Using your information, I found this video on YouTube that walked through troubleshooting my exact problem:

https://www.youtube.com/watch?v=IyJWLmlnQ4I

I followed all the same troubleshooting that this guy did and I had all the same problems. I have ordered a new circuit board which should arrive on Tuesday. I will update this post when I get it and install it.


Thanks so much for your help!


Michael

[Djfred]

You might want to try some contact cleaner.I have had the same problems with my hot water heater and furnace.Contact cleaner cured them every time.