Hello everyone,

I don't know if someone out there can help but I have a Carrier 30GX chiller which will not prelube.

I believe the oil pump is supposed to start before everything else fires up. This is not happening on one of the circuits. The control boards have been swapped, so I am confident that this is not the problem. What else could hold the pump off? There are no alarms so I presume this circuit is waiting for something like the oil temperature to be correct! The heater is working so I am at a bit of a loss.

Many Thanks