I preformed a single system heat maintenance on a 2021 heat hump. On my inspection of the thermostat I found that there was no power being supplied to the thermostat. I then proceeded up to the attic where I found that there was a breaker tripped in the air handler. When I turned it back on the breaker wasn’t receiving 240 volts. I then checked the main breaker box and found that the furnace breaker was tripped. I reset the breaker and proceeded back up to the attic to find a blown fuse. I replaced the fuse and restored power. Everything was working at first, then after a few minutes of running the unit tripped the main breaker again. I found the heat sequencers to be faulty causing the unit to trip the main breaker. I unwired the heat sequencers from the unit and provided a call for just heat using the heat pump. The heat pump is working properly. Upon further inspection of the unit I found the return duct, blower wheel and plenum boxes to be extremely dusty. I proceeded outside to ch
