Hello, I have an unknown A/C / gas heater roof top unit. There are no data plates anyplace on this unit from the components it looks like it was made in the late 1980s. Here are the parts I have replaced: 1. Rebuilt the 24 volt relay board that the thermostat connects to. I know it now gets 24 volts to the ignition module and the A/C will now come on. 2. I had to replace a bad Honeywell gas controller with a Robert Shaw universal ignition module. 3. Have replaced the blower motor and run cap. Current result: Good news the heater now comes on works great. Bad news is that while the blower motor works fine for the A/C it will not turn on for the heater. It will move slowly and the relays make a buzzing sound. Bad transformer maybe? Any thoughts? Thanks! Greg :wall:

Hello All, When running my furnace blower in the "Fan On" mode, no heat, it runs for approximately 5 minutes then shuts down for approximately 1 minute and starts running again. When I run the heat and have the fan on the "AUTO" mode it runs fine throughout the heating cycle. I ran my central air with 'Fan on Auto and this also caused the fan to cycle off. It seems to be related to the motor running on High Speed. Any help wpould be much appreciated. By the way this is the second Blower Motor in 13 years, with the first being repalced after just 4 years. Need help with this , can't believe it's another motor. John