
There was a problem with the fuse on the HVAC board frequently closing. It turned out that the service technician was pulling hard on the wires in the external AC unit and scratched an unused thermostat wire, exposing an internal wire that occasionally made metal contact and shorted out. I bought this pack to use in troubleshooting. I looked through 4 fuses until I found the cause. Since then it has worked flawlessly. The best price I've found for 3A fuses.

TWTADE/AC 24V 10A Coil Electromagnetic Power Relay 8 Pins 2DPT 2NO+2NC With Indicator Light And Socket Base -YJ2N-LY
9 Review

Universal Rotary Cam Selector Latching Switches - VictorsHome Changeover Switch LW28-32 With 3 Positions, 12 Terminals For 690V, 32A Capacity
9 Review

Adjustable AC Current Sensing Switch: SZC23 No AL-CH Model, 0.2A-30A Range
14 Review

Vacuum cleaner KARCHER VC 3, yellow
176 Review