I have a Suburban water heater with dual 120-volt/LP. It works fine on electric. However, when I try to use the LP, the pilot light lights and stays on. But when I try to turn the valve to “On” for the burner to light, the pilot light goes out. What should I check out? Thanks. —Virgil
I assume you have a Suburban SW6PE or SW10PE, which are 6- or 10-gallon models with LP gas and electric. Does this happen when you are plugged into shoreline power or dry camping? The reason for asking this is the module board needs 12-volt power from the house batteries. If they are sulfated, the voltage can look good but drop like a rock when anything tries to get power. If you are plugged into shoreline power, the converter will typically provide a maintenance charge of 13.2 volts when it is not charging. Make sure it is plugged in and getting sufficient power.
What to check
If you are getting a steady flame for the pilot, it’s probably not the thermocouple. According to the service manual, you should turn the gas knob past the white line and then to the “on” position. If you are operating it in this manner, then you need to check the burner assembly for restrictions in the orifice, burner tube, flue, and exhaust. I would suggest using an air gun similar to the one here used in cleaning out the burner assembly of a refrigerator. You may even need to replace the orifice if it cannot be cleaned and is restricting LP flow.
Do other LP appliances work?
Do all the other LP appliances work as designed? If you have a weak or faulty LP regulator and not getting proper pressure, you would notice it in other appliances. A quick test is to light one of the burners on the stove top and look for a steady blue flame, then light another one, and then the third. This will show what is happening when more than one source is drawing LP and if your regulator is doing it’s job. If the flame goes down and stays down, the regulator is not keeping up.
If all these check out OK, then it’s time to get a certified technician to perform a water column or pressure test at the water heater to determine the airflow from the gas valve and/or orifice, as it would appear that not enough LP is getting to the burner assembly.
Dave Solberg is a leading expert in the RV industry and author of the “RV Handbook” as well as the Managing Editor of the RV Repair Club.
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