Is 165mV Enough?

[Damn Yankee]

Hey Folks,

I have a Heatilator GCDC80, about 25 years old. It has a Robertshaw 7000MVRB-4-LC-LP valve. Since we purchased the home 8 years ago, the flame is weak. The pilot is blue and strong. The burner is very blue at every orifice but the combined flame is yellow and does not reach half the log height.

The voltage drop across the valve's switch terminals is less than 18mV. The thermopile outputs only 165mV. I'm thinking the thermopile is my culprit, but I do not understand how the valve turns on at all. When lighting the pilot, the thermopile heats-up within 5 seconds to sustain the pilot. When the fireplace is turned-on, the flame is almost immediate - just sissy.

I haven't checked pressure at the hand valve, but the other LP appliances work just fine. Do you think my problem is the thermopile and if so, how does the valve open at all?

Thanks to All,
John

 

[Millbilly]

No. I would suspect a partially blocked burner orifice. You really need to check pressure out or just take it apart and inspect.

 

[Damn Yankee]

Thanks for the reply, Millbilly (I love the User Name)!

After I posted I did some more troubleshooting. The 165mV was loaded (switch ON). Switch OFF it is nearly .5V. I guess I will pull the logs and check the orifice.

Thanks,
John