SW6D acting up

[Shaft0201]

Got the Suburban SW6D in my 2008 toy hauler. It’s a newer trailer to me. Since I have got it the water heater has given me issues. The trailer sat for a couple years without use outside when I got it. The water heater sometimes fires right up and other times takes 20 min to start as it goes into lockout mode after 3 attempts and then I have to try again and again. Once it does start it heats up the water all the way, but sometimes will not come back on when the water cools on it’s own. I have cleaned out the tube, cleaned the contacts that make the actual spark and flushed it and put in a new anode. I have ran the burners for a couple minutes on the stove before starting and it makes no difference. Any ideas on this? It’s the direct spark model, NO pilot light, NO electric mode. Only propane. Thanks

[RedRollingRoadb]

Both solenoids need to open to light. If one is bad it is likely to be the one closest to the tank. White-Rodgers makes it, or is the replacement. I know PPL Motorhome sold them. I'll see if I can find the part number and edit this later.

EDIT: It is a White-Rodgers 3475

[Old-Biscuit]

Did you check the solenoids?
40 ohms

Do you get a spark?

[Shaft0201]

Just went and got a new spark electrode and installed, but no change. Can’t even get it to fire up at all. What you all think is next? FYI, stove burners and fridge work just fine off propane.

[Shaft0201]

I’ll start trying these things. Was thinking about just buying a new one as there about $200 online, but if it will just be a cheaper fix then that’s the obvious route. Just hate to spend $200 in parts trying to elemanat possible issues. Thanks

[Harvard]

There are two solenoid operated gas valves that may go intermittent before failing completely. The coil resistance of a good solenoid is about 40 Ohms but that may not help your troubleshooting when intermittent.

[Old-Biscuit]

The spark electrode is used to provide ignition BUT is also used as return path for a milliamp flame proving signal..
No return of signal and circuit board shuts down gas valve...3x lock out

Spark electrode \
Could be dirty/sooted up....clean with emery cloth
Out of position......must be 'englufed' by main flame when it lits
Ceramic insulator....cracked & tracking to ground. New electrode
Dirty/corroded/loose ground ----electrode mounting screw provides ground...clean/tighten
High tension wire....corroded/dirty/loose ---clean up/tighten up

OR replace spark electrode with new