Girard GSWH-2 Burner Won't Stay Lit After Winterization—Troubleshooting Steps

[XBeaudsxx]

My tankless is failing being just over a year old. Burner is failing to stay lit.

I've gone through next to everything I possibly could. I have 0 codes at the UCP. When I turn the power on at the heater, and go back inside the rv, I have power to the UCP. When I hit the power button on the UCP, the green indicator light next to the C/F fails to come on.
Verified voltage 9-11vdc at the board xk connectors.

Verified continuity on all thermostats. The antifreeze thermostat is showing open line. Is this enough to trigger the ucp to not display the green c/f light? Im completely locked out of changing temps, but that's not the true issue, or maybe they stem from each other..

After multiple attempts at calling for hot water the green light will eventually turn on, the girard will initiate the blower, ignite fairly quickly. Burn for about 4-5 seconds, and then go out. Again, does not throw any codes.

-Checked all Sinks and showers for "mixing"
-Used 2 different sources of city water.
(GPM tested both sources)
-Hooked up to Rv Water Inlet with both a regulator, and no regulator.
-Tested using only Rv tank/water pump supply.
-Propane is full.
-I have 12vdc at the board (only green light on board.
-Descaled in hopes of water flow sensor blockage.
-Replaced the water flow sensor on suspicion.
-Verifed voltage on new flow sensor. (2.6vdc)
-Thouroughly cleaned everything.
-Cleaned Flame Rod/Spark Igniter
-Removed Inlet filter on backside of tankless and cleaned.
- Flow setting on backside is set to max.

This is coming out of winterization, no I do not have any bypass valves. Im stuck between the thermostat or (both) possibly a bad gas regulator at the tanks/or a leak in the line somewhere. When it does burn for that 5 seconds, it reaches about 100 degrees when it shuts off (have the temp set at 115) As id imagine its a low stage/high stage for heat, id imagine the requirement for propane would increase as the burner tries to burn hotter, which leads me to thinking its a fuel related issue.

If anyone could point me in the right direction..

 

[NMWildcat]

Call Girard tech support. They have been very helpful to me in the past. They were bought out by LCI in 2022, but kept most of the staff according to the tech I talked with last year.

Manuals have some diagnostic steps in them and the phone number for tech support is at the bottom of the main page.

Girard Other Products | Lippert Customer Care Center

support.lci1.com

 

[XBeaudsxx]

Call Girard tech support. They have been very helpful to me in the past. They were bought out by LCI in 2022, but kept most of the staff according to the tech I talked with last year.

Manuals have some diagnostic steps in them and the phone number for tech support is at the bottom of the main page.

Girard Other Products | Lippert Customer Care Center

support.lci1.com

I called Lippert support last week and they recommended the water flow sensor. Otherwise they were at a loss for words and had no idea what it could be. I've gone over the manual about 2 dozen times to see if there was something I've missed, and I've sadly found nothing I haven't tried. Besides a complete board replacement. Board shows no indication of being bad.

 

[NMWildcat]

I might try calling again and maybe get a different tech.

Sounds like you have done everything suggested.

I have the gen 1 Girard and your problem sounds like when my air pressure (exhaust fan) sensor (sail switch) is bad. Looks like the gen 2 has a water flow sensor, a flame sensor, and an air pressure sensor (not a sail switch). If you tested all the sensors, then maybe it is the board.

Might also consider a certified RV tech. When I start considering throwing parts at a problem as I don't know the actual problem cause, I call my local trusted RV tech. Usually saves me a lot of frustration and sometimes money as well

Good luck! Let us know how you resolve the problem.

 

[XBeaudsxx]

I might try calling again and maybe get a different tech.

Sounds like you have done everything suggested.

I have the gen 1 Girard and your problem sounds like when my air pressure (exhaust fan) sensor (sail switch) is bad. Looks like the gen 2 has a water flow sensor, a flame sensor, and an air pressure sensor (not a sail switch). If you tested all the sensors, then maybe it is the board.

Might also consider a certified RV tech. When I start considering throwing parts at a problem as I don't know the actual problem cause, I call my local trusted RV tech. Usually saves me a lot of frustration and sometimes money as well

Good luck! Let us know how you resolve the problem.

Called them, they recommended a board replacement. Swapped it out and same results. With both the old board and new board, when I power the unit on and go back to the UCP, turn that on, it does not turn on with the first click, I have to press it twice to get the screen to illuminate. Is this normal behavior?

 

[XBeaudsxx]

Update:I requested a new UCP before Lippert sent out a new water heater. The UCP has corrected my issues, and the unit is working properly again.