I have a Brivis Buffalo 85 Ducted heating system. The Pilot is lit & stays alight but when I turn the electonic thermostat on to fire up the unit, the main burner does not cut in & the fan blows cold air .
When I bridge out the terminals for the thermostat (R &W). the main gas valve clicks (or clunks) as if it is opening but still no main burner. I have made some enquires & I am getting conflicting info on whether this means the problem is the main gas valve or the main electonic unit in the system. Does anyone know what voltage should be across the terminals of the gas valve? (It is a 3 terminal gas valve not 2).
I read on another post that you can test the gas valve by using ohms with the power off, is this correct?
There appears to be a retard valve across the White & Blue terminals of the gas Valve unit. This has voltage up until I bridge the (R &W) terminals of the thermostat.
The gas valve itself, is across the blue & orange wires of the 3 terminals & I am getting voltage across these terminals when I bridge out the (R & W) terminals of the thermostat connection. I am therefore assuming that the electronic unit is sending the correct voltage to the gas valve but there is a fault in the gas valve unit itself.
Any advice appreciated