Originally Posted by tbone!
I have a 2015 195RB with an Atwood hot water heater G6A-7. I have replaced the thermocouple assembly and removed the main burner tube and made sure it is 100% clear. The heater functions and shuts off when the set temperature is reached. My concern is the extremely loud main burner! It can be heard three campsites over. In previous outings this summer, the unit did not sound like this.
Is this something caused by incorrect propane pressure? Is there a method to check the pressure or is the regulator nonadjustable?
"Roaring" means it's a lean burn. If it didn't roar before, that means it was a proper richer burn at that time. If you haven't changed the position of the air shutter...
...then that means the main burner is now getting less gas (or more air) for some reason. That could be due to a drop in LPG pressure or a restriction/debris in the orifice or main burner tube.
The Atwood 91602 (Robertshaw) gas valve has a 1/8" test port on the bottom next to the pilot connection. Test with a manual or digital manometer.
I'd check the main LPG low pressure regulator at the tank first to make sure the entire trailer is being fed with the proper pressure before testing the water heater gas valve. Why? Because you have to twist the 90° elbow and orifice out of the way to get access to the test port. Then you have to put the main burner back into place on the elbow and devise a way to ignite the pilot and main burner while it's detached from the tank so that the valve will activate. You'll only get pressure at the test port while the valve is open and in operation, and that will only happen when the pilot thermocouple is sufficiently heated and the thermostat is turned up.