RV Repair: Gas Water Heater, mallard travel trailer, gas water heater

Question
I have an Atwood Model G6A-7 in my 1994 Mallard travel trailer. I light the pilot light and and turn the knob to on. The flame comes on and runs for long enough to heat the water. The flame goes out after the water is hot, but the pilot light also goes out and the heater has to be relit each time I want more hot water. Where should I start in this repair?

Answer
Hi Joe,
     Below is a list of the possible causes of your failure.  Without a manometer you wont be able to check or set the gas pressure.  If you have a multi-meter you can check the output of the thermocouple.  It should be around 25 milivolts.  If its below 15 I would change it.


PILOT OUTAGE

CAUSE
Gas Pressure incorrect

SOLUTION
Set inlet pressure to a minimum of 11” W.C. with two or more appliances running

CAUSE
Blocked “U” tube

SOLUTION
Remove obstruction

CAUSE
Improper air adjustment

SOLUTION
Re-align main burner air shutter approximately ¼ open or greater

CAUSE
Weak thermocouple

SOLUTION
Replace thermocouple

CAUSE
Poor pilot flame

SOLUTION
Clean or replace pilot orifice


CAUSE
Weak gas control magnet

SOLUTION
Replace gas control

CAUSE
Defective E.C.O. in control

SOLUTION
Replace gas control and check the flame, it should be high enough to engulf the thermocouple at all times.

The pilot flame should be just large enough to cover the tip of the thermocouple.  If it's too large it often gets put out by the main burner coming on or going off.  I hope this helps and good luck.

Darren