Heat n glo sl550trs-c

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New Member
Oct 23, 2021
I have a heat and glow gas insert fireplace and have the following issue. There is a thermostat on the wall as well as an on off switch on the gas valve. Occasionally, when the thermostat is in “heat on” mode the burners do not come on. When this happens I can flip the on / off switch on the gas valve to on for a couple seconds and the burner stays lit when switching it back to off until the thermostat reaches desired temp and it shuts off normally.

thermopile is reading over 600mv when nothing is on
when thermostat is in “heat on” mode and burner is on, it reads over 300mv
when on/off switch is on, it reads just under 200mv with thermostat in either “heat on” or off mode.

when the thermostat goes into “heat on” mode from off I can hear the same click noise regardless if the burners come on or not as if the circuit contact is made to open the valve.

Picture of gas valve is attached, many thanks on any ideas of possible issue!



Full Time RVer
Staff member
Dec 2, 2008
Wherever we're parked
Pull the thermostat & jump the wires a couple of times.
If the unit comes on EVERY time, then the T-stat is questionable.