Stephen Johnson
Hi Tom, if nothing has been touched and everything else still works its likely just a loose wire.. Wires actually get quite warm under normal operation, the heating and cooling actually loosens the screws of the terminals over time, if they get loose enough it can actually loose connection and suddenly stop working. This is why an inspection should be done on a system every 10 years, part of the inspection process is to retighten everything. Depending on how things are wired it may take a little time to find the fault but at first thought its likely something loose than broken.. Cheers Steve TD Survey, Electrical and Services Ltd
