Customer had no heat in home, first went down to furnace and found roll out switches tripped, reset switches and furnace came on ran for 30 seconds and shut off then threw a code for A15 and A18 heat exchanger getting overheated, the heat exchanger will need to be replaced as well as gas valve due to not being able to adjust high and low fire springs in gas valve, heat pump not coming on due to compressor locked out on 01 code low pressure, low side pressure at 36 and high side pressure at 80, recharged system with 16 pounds of 410 performed electronic leak search but could not detect leak, ran system for about a half hour checked every single vent in home and had a delta t reading of 28-34 degrees, system operational and working will need to follow up about heat exchanger and gas valve.