Trying to trouble shot a house ac.

Air will blow but outside unit is not turning

The circuit board is flashing a code. 8 fast. 3 slow

Board is. HK38EA004

Can’t find trouble codes for this board.

Look on backside of the door you removed to access the board, should be printed there or on the side of furnace enclosure. Or check owners manual.

No codes just a wiring diagram

Looks like low pressure lockout: https://dms.hvacpartners.com/d...ec%26CurrentPage%3D1

If the system pressure is too low, the compressor won’t run so as to protect itself.

^^^ Ding ding ding.

quote:

Originally posted by PowerSurge:
Looks like low pressure lockout: https://dms.hvacpartners.com/d...ec%26CurrentPage%3D1

If the system pressure is too low, the compressor won’t run so as to protect itself.

Thank you.

So this thing has a Carrier Infinity Thermostat.

Got it to show the fualt what was the same as PowerSurge listed. The thermostat said timed out for 4 hours. When I saw this we had about 15 minutes till it would time back. It did come back on and is working normally.

Not sure what caused the issue.

This wasn't my house. This was a good friends house who has 3 young kids, I was trying to help out since no one was coming out tonight to look at it.

While operating the LPS opens and shuts off the unit. Pressures equalize, closing safety switch and the unit is up and running again after timeout.

Could be any one of several possibilities:
Dirty filter/s
Dirty evaporator coil
Dirty squirrel cage
Weak blower motor
Blocked/closed registers
Refrigerant restriction
Low refrigerant

If new install,
Inadequate supply/return ducting
Improper blower speed (CFM)