problem with Suburban DSI water heater

Rock2 wrote:

Old-Biscuit wrote:
When voltage is sent to spark electrode voltage is also sent to gas valve solenoids for 6-8 secs.
When main flame lights a signal is sent back thru spark electrode to circuit board as a flame proofer. This milivolt signal is generated by the main flame thru 'flame ionization'.
A faulty spark electrode, a bad wire/insulation to spark electrode, a bad ground and a bad circuit board could be problem. You can have the board tested at an RV Shop to eliminate it as problem.

Yes I might do that take the circuit card to have test at RV shop. If the card is bad, where is a good place to buy a good realiable circuit card?

One of the best replacement boards is from Dinosaur Electronics....LINK

I cleaned the contacts where the ribbon edge connector goes on the circuit board. That cured my starting problem. The voltage for the flame sense is very low and any resistance is a problem.

open the door and look at the upper right hand corner. You will see (2) 1/4" hex screws....unscrew each a couple turns and retighten. This is the point that the ground is attached inside....if the ground anywhere is poor it will not see the needed signal voltage and turn the gas valve off. Also a ground wire added between solenoid ground wire to the burner screw helps with eliminating delayed ignition.

Old-Biscuit wrote:
When voltage is sent to spark electrode voltage is also sent to gas valve solenoids for 6-8 secs.
When main flame lights a signal is sent back thru spark electrode to circuit board as a flame proofer. This milivolt signal is generated by the main flame thru 'flame ionization'.
A faulty spark electrode, a bad wire/insulation to spark electrode, a bad ground and a bad circuit board could be problem. You can have the board tested at an RV Shop to eliminate it as problem.

Yes I might do that take the circuit card to have test at RV shop. If the card is bad, where is a good place to buy a good realiable circuit card?

I had the same problem with my Atwood HW Heater. I took it apart and put the metal parts on a wire wheel, then cleaned the lugs, put it back together and it works fine, I also purchased a 110 volt assy for $66.00 on amazon included everything to do the job so I am covered now if the gas fails, plus I don't have to use LP in the campgrounds..

When voltage is sent to spark electrode voltage is also sent to gas valve solenoids for 6-8 secs.
When main flame lights a signal is sent back thru spark electrode to circuit board as a flame proofer. This milivolt signal is generated by the main flame thru 'flame ionization'.
A faulty spark electrode, a bad wire/insulation to spark electrode, a bad ground and a bad circuit board could be problem. You can have the board tested at an RV Shop to eliminate it as problem.