I have a goodman furnace which has been running fine for several years. Now whenever the thermostat calls for heat or AC the circuit breaker is tripped. I had to have work done to another furnace and when the man saw this furnace he said it was notorious for bad relays and to replace that before I ever called out a tech. Does this seem reasonable for this problem and if so which relay is the most likely culprit?

What kind of furnace is it. Gas,oil,electric?

Model number?