Suburban water heater not lighting

Moved from General RV'ing forum.

Meter set to DC Volt
One probe on terminal at solenoid
One probe to good ground

Turn on 'gas' switch..check voltage reading when sparking is occurring

Old-Biscuit wrote:
With sparking occurring you are getting 12V DC power to unit (to/thru ON/OFF switch, to/thru both t-stats and to module) Question is are you getting power out of module to gas valve?

Check for 12V DC power to gas solenoids (brown wire) when sparking is occurring.
Power is sent from module to gas solenoids for 6-8 seconds during sparking attempt.....IF main flame occurs an induced signal is sent back to module via spark electrode that holds gas solenoids open.
IF no main flame then module shuts down power.

IF you are getting power to gas valve......is it opening (bad solenoid).
If opening is gas flowing.....blocked orifice, burner tube

If you are NOT getting power to gas valve.......bad ground connections or bad module

Could you guide me through the steps of testing these connections with a multi-meter?

With sparking occurring you are getting 12V DC power to unit (to/thru ON/OFF switch, to/thru both t-stats and to module) Question is are you getting power out of module to gas valve?

Check for 12V DC power to gas solenoids (brown wire) when sparking is occurring.
Power is sent from module to gas solenoids for 6-8 seconds during sparking attempt.....IF main flame occurs an induced signal is sent back to module via spark electrode that holds gas solenoids open.
IF no main flame then module shuts down power.

IF you are getting power to gas valve......is it opening (bad solenoid).
If opening is gas flowing.....blocked orifice, burner tube

If you are NOT getting power to gas valve.......bad ground connections or bad module

Look at this link for a list of problem scenarios and potential solutions.