Just bought a thermostat for my Propex X1 having bought the unit s/h without one My question is, the thermostat control has 4 wires - red black o r a n g e and purple but the unit only has 3 - red black o r a n g e Connecting up the 3 makes the unit fire up and work perfectly, but it won't "purge" when turned off. Also the "fan-only" option doesn't work. Bench testing with the black and red wires connected to 0v and 12v gives the following o r a n g e wire...................heat..............off................fan "call for heat"..................12v................4v................4v no "call for heat"...............4v................4v................4v Purple wire "call for heat"....................0v................0v................12v no "call for heat"...............0v................0v................12v Might be time to call the Propex factory for advice, unless anyone on here has a solution.... Thanks in advance Mike
Just had the definitive answer back from Propex's very helpful technical guys. The X1 model is a very old one they describe as used by the GPO! And it doesn't need a "purge" system to keep the fan running for a while after the burner is switched off. Hence I've now sold the thermostat control and will use a simple switch for the Propex.
