I have Bryant Heating and cooling system. The model is 373LAV. recently not worked. I checked because the circuit board fuses broken. I replaced one and keep broken. Here is the circuit board model HK42FZ0009. Any one please let me know what maybe the reason for blowing the fuse. Thanks!

you have a low voltage problem somewhere. checked for broken or chewe wires by outdoor unit. also you could have a bad contactor and everytime it closes it is making the fuse pop.

Check for low voltage shorts around the compressor, high and low pressure switch wires will rub on the refrigerant lines and short out.

Thanks for your response my question! I order a new control board, replace the old one and have the same problem which keep blew the fuses. My further check, found out the low voltage short cause by two devices look like serial together which connected with red wire to Gas Burner side from control board. I don't know what is these. It's looks like power transistors with two connection. Could be so called ignitor? Where can I buy replacement parts for it?

you could have a short in the system.

that is a safty for the heating system.

The item in the picture is a safety limit that trips on unusual high temperatures. Some have a reset button in the center. It could also be a operating control of sorts but that depends upon where it is locared in the system. If you test and one of the 1/4 inch male prongs to the metal outside of the base and there is continunity then the control is internally shorted and needs to be replaced.


http://www.gogeisel.com/geiselonline/support/Bryant/373LAV_376CAV_383KAV_395CAV_Gas_OM.pdf