Suburban Water Heater Troubleshooting

[Happy_Prospecto]

My Suburban SW10DE Water Heater will not work off of propane. What would be the procedure to troubleshoot the thermostat. I see the two terminals and was going to ohm test these but with little wire running between the terminal on the other side of the wires, wouldn't that give me zero ohms?

My other question would be how do you get to the control board?

Thanks.

[Happy_Prospecto]

Well I tested the thermostat and it tested good, went to CW and they had a gas valve in stock but wanted $95 so I ordered a valve for $57 on the net and should be here next week.

[GENECOP]

Awsome advice here, thanks...

[Harvard]

forumcoach wrote:
The reason Suburban Gas Valves fail is because a majority of them drip on the coils. The drip tray underneath the TP Valve is almost always bent downward away from the burner box causing them to drip onto the coil and eventually short out.

The proper angle for the drip tray is for it to be bent up causing the them to drain next to the burner box. You will see a little notch in the drip tray on the burner side as part of the drain design.

Suburban has told me that the Manufacturers are bending them down at install. Majority of them in the field are wrong so hard to believe.
Regardless, bend the drip tray up to prevent failure to your new gas valve.

Good Stuff, Thanks.

[old_guy]

this happened to mine two years ago when we went to Yuma. we used the electric side all winter and it gave us plenty of hot water. when we got home my friend came over, he is a rv repair tech and he took off the black reset cover and wiggled the 12v wire and it ran on propane, fired right up. clean the terminal ends and put some electric grease on them and it will work. hopefully that is what is wrong with yours.

[forumcoach]

The reason Suburban Gas Valves fail is because a majority of them drip on the coils. The drip tray underneath the TP Valve is almost always bent downward away from the burner box causing them to drip onto the coil and eventually short out.

The proper angle for the drip tray is for it to be bent up causing the them to drain next to the burner box. You will see a little notch in the drip tray on the burner side as part of the drain design.

Suburban has told me that the Manufacturers are bending them down at install. Majority of them in the field are wrong so hard to believe.
Regardless, bend the drip tray up to prevent failure to your new gas valve.

[Old-Biscuit]

Propane side uses 12V DC so the easiest way to test is turn the switch ON

12V DC (+) from DC Dist Panel (fuse) goes to ON/OFF Switch then to DC Junction Box (left side on back of tank) Red wire-----DC power from switch, Blue wire-----DC going to Light at ON/OFF switch), Yellow-----ground)
From Junction Box
Red wire goes to High Limit T-stat (top one that is resettable---trips on 170*F).......from Hi Temp thru wire to Normal Temp T-stat (lower one...opens at 130*F). Then Red wire goes to control module

Control Module.......right side on back of tank
Send 12V DC to gas valve and at same time to spark electrode.
Gas valve stays open for 6-8 seconds while spark occurs...main flame lights...........gas valve stays open until normal t-stat opens.
Main flame doesn't light off and 'prove' then gas valve closes. Control module will try 3 X then locks out (fault light)


Gas valve would have 12V DC on both solenoids during spark electrode firing. Brown wires......black to ground

Solenoids should ohm at 40......inboard one (closes to metal pan) gets weeped on by T&P Relief Valve above it

So trace the DC....where does it stop?






ON EDIT:

I was typing response while you were testing.
Guess you have found problem

HERE is some info about solenoids used.

And HERE is a gas valve on sale.

[Happy_Prospecto]

Harvard, I just pulled the wires off the gas valve and measured ohms across the coils and they test open right now. I guess that is my problem. Now to find a gas valve solenoid tomorrow.

[Harvard]

A common problem with Suburban WHs are gas valve solenoid coils that go open circuit. There are two coils and they should be about 40 ohms each.

[GENECOP]

I am watching, similar problems with mine...