Suburban 6 gallon water heater issue

[maxum1989]

I had a small propane leak at the gas valve on my water heater which resulted in a little fire which melted the gas valve solenoid. I'm not sure what made the fire go out, but the red light came on inside which is when I discovered the problem. No real damage other than some soot and the melted solenoid.

So, I ordered new solenoids (old ones did read bad on a meter) and replaced those. To my surprise it still didnt work.

Here us what I know:

There is propane and proper power to the trailer.

The gas valve works. I have checked it by jumping it off a battery, it clicks just like it should. New solenoids are working. Gas is flowing. In fact I can get the water heater to fire using this hot-wiring method.

There isn't the proper 12 volts running to the solenoid.

The switch inside the trailer is working properly.

My two last guesses are the thermostat switch or the control board. The board is making a faint squealing sound (I didn't notice this before but who knows, maybe it always did that?).

Anyone have any ideas or tips on how to test the thermostat switch or the board?

[maxum1989]

Yes, protective cover will be installed as well.

[Old-Biscuit]

maxum1989 wrote:
Dinasour board ordered. Thanks again Old biscuit for your help with this.

Protective Cover......??

[maxum1989]

Dinasour board ordered. Thanks again Old biscuit for your help with this.

[Old-Biscuit]

Suburban SW6D (SW6DE, SW6DEL etc etc etc)all use the same circuit board
#520814

Dinosaur Electronics replacement would be the UIB S circuit board and you would need the protective cover for that Dino Board

Dino UIB S information

[enblethen]

Dinosaur Electronics
Cover
Suggest you call Dinosaur to insure you get the correct ones. Then order via Amazon as they do not sell direct.

[maxum1989]

Ok. Using the information above from Old biscuit, I tested voltage all through the system. Good twelve volts at thermostats, then on the red wire at the board, but only .5 volts on the brown wire at the board. There in lies the problem. Solenoids are not operating properly to open gas without the proper voltage from the hoard. Thank you Old biscuit for walking me through this.

I don't know how but perhaps the fire burned the solenoids and then sent some kind of surge to the board frying it. Who knows.
Now I know which part to get to fix the problem.
Is there a preferred board to get for the Suburban 6 gallon water heater?

[maxum1989]

Thank you for the detailed response. I will check these things next.

[Old-Biscuit]

maxum1989 wrote:
So I checked the ECO and thermostat for continuity. Seems as good. I took off the two wires, checked continuity through the ECO from one side to the other. Then did the same to the thermostat and then had continuity from top ECO to the thermostat. So am I correct to assume the board is the only thing left to check? Is there anything that can be done to the board to check it?

Check actual DC Voltage from On/Off Switch to the set of t-stats (DC goes to HI Temp (Top) first then thru connecting wire to Normal Temp (bottom)
Got 12VDC at RED wire on Bottom t-stats then check that you are getting 12VDC on RED wire at circuit board

If Normal T-stat is closed (water temp below 100*F) and you have 12VDC on RED wire at circuit board then you should have 12VDC on BROWN Wire from circuit board to GAS Valve solenoids and Spark Electrode should be FIRING (Get DC Voltage at same time)

Got DC TO circuit board but No DC from circuit board on BROWN Wire....bad board OR lousy GROUNDS (Inside DC Junction Box, Yellow wire from circuit board, Gas Valve solenoids)

[maxum1989]

So I checked the ECO and thermostat for continuity. Seems as good. I took off the two wires, checked continuity through the ECO from one side to the other. Then did the same to the thermostat and then had continuity from top ECO to the thermostat. So am I correct to assume the board is the only thing left to check? Is there anything that can be done to the board to check it?

[Old-Biscuit]

Thermostat opens at 130*F --- closes at 100*F for reheat cycle
Water temp has to be at 100*F or lower
Can check continuity thru a cold t-stat

HI temp T-stat opens at 170*F and has to be manually reset (Push to Reset cover above gas valve----right side is the 12VDC for gas)
Hi Temp T-stat is always closed unless it trips


Circuit board gets 12VDC after it has gone thru the set of t-stats
Course that is IF you have 12VDC to/thru the on/off switch and thru the DC Junction Box

[enblethen]

Check the ECO and thermostat for continuity