Suburban SW6D

Moved from Forum Technical Support

Is voltage present at the switch, control board, thermostat?

12V DC (+) comes form DC Dist Panel (fuse)
Goes to ON/OFF switch
Then to DC Junction Box on side of WH tank

Inside box are 4 OEM wires
RED...DC + to t-stats
Blue...DC + from circuit board to fault light in switch
Yellow & Green DC -/grd

RED wire goes to high t-stat lug thru it then via hard wire to normal t-stat thru it and from lug to circuit board.

DC Voltage from circuit broad to gas solenoids while sending high voltage to spark electrode




Easiest place to check for DC Voltage is at t-stats
Remove rubber cover (above gas valve with 'reset' buttons
Check for DC voltage at RED wire on top lug----that comes from ON/OFF switch
IF No DC then issue is inside junction box, at switch or with fuse

Got DC ...then check for it at bottom lug.
No DC..then top t-stat is tripped---push reset, wire is burnt into---replace set of t-stats (12V DC ones)

Got DC...then check for it at gas solenoids WHEN you turn it ON (DC Power is only on gas solenoids for approx. 6 seconds while spark electrode gets voltage)
Check that spark electrode is properly gaped (1/8"), high tension wire is tight/clean connection.

Example of t-stats
Left set is for 120V AC element
Right set is for 12V DC propane
Top is Hi temp/bottom is normal temp t-stats