RV Water Heater Care & Maintenance PTII

LP gas mode

Most modern RV water heaters are the DSI (Direct Spark Ignition) type, which has no pilot light. When you switch on the water heater in LP Gas mode, the gas mode thermostat will call for it to be heated as needed. When heating is called for, the heater control circuit board opens the gas valve and activates the igniter, making a spark at the front of the heater’s gas burner tube, and [hopefully] igniting the flame. At the same time, the control board starts sensing for a flame [the igniter doubles as a flame sensor]. When the burner flame is sensed, the ignition sequence is complete. If no flame is detected after a preset time (about 15 seconds), the gas valve is closed, the igniter is turned off, and the system “locks out,” meaning it won’t allow another attempt at restarting until the system is reset by turning it off and on again. Usually a red indicator light will show at the LP Gas Mode switch if the heater fails to light when needed.

Problem - pilot outage

  • If thermocouple or gas control magnet are weak and not performing as usual than replacement is required.
  • If pilot flame is poor recommendation is to clean or replace orifice.
  • If U tube is blocked, remove the obstruction.
  • Adjust the gas pressure per instructions from manufacturer manual if you have an incorrect reading.
  • Adjustment is required if there is an improper air adjustment and for main burner alignment.

Problem - No sparks on electrodes

  • Secure electrodes to the main burner if it is loosely attached.
  • Reposition electrode to have a proper gap.
  • Clean dirty electrodes.
  • Secure wire connection on circuit board if it is loose.
  • Replace electrode if the insulation is cracked or wire inside is loose.
  • Replace circuit board if it defective.

For more tips about RV maintenance and service, contact Mike at mikeb@rvglass.com

or call (800) 551-9149 ext. 2030