Saturday, October 31, 2009

Water Heater Pilot Outage

I have a Nomad 23-1/2 foot trailer. It has a Suburban water heater. The orifice was plugged on the LP pilot. I replaced the pilot unit, but now I can't keep the pilot lit. I even made sure all of the air was out of the lines by lighting the stove at the other end of the trailer. Any suggestions?
Steve, (Longview, WA)


Steve, here are a few things to consider regarding your pilot flame situation. First, has anyone checked the LP pressure lately? For RV appliances to run at their optimum, the system regulator should be set at 11.0 inches of water column. Use of a "U" tube manometer will yield the most accurate results. If the flame goes out as soon as you release the button you may have a faulty thermocouple; provided the thermocouple is correctly positioned in the flame to begin with. Only the tip of the thermocouple, the hot junction, should actually be in the flame. Additionally, the other end should only be one-eighth turn tighter than finger-tight into the control valve. Too tight of a connection here will compress the contact pad and cause insufficient voltage to reach the electromagnet. RV service shops can easily bench test the thermocouple. If the pressure is correct and the thermocouple correctly positioned in the flame, the electromagnet in the gas control valve could be faulty, though this is not usually the most probable cause.

Finally, verify that the correct size orifice was used in the pilot tube. Contact Suburban or your local repair center for the correct size for your model.