viveen

York 90 plus upflow furnace summer HVAC operation.
The draft inducer fan runs continually and will not shut off until i kill power to furnace. HVAC working normally and keeping house cool.

Five red flashes diagnostic.
Question does a draft inducer fan even have to run when the airconditioner is on?

kok328

"Question does a draft inducer fan even have to run when the airconditioner is on? "
Answer: No, never when in A/C mode.
Check on the back of the removable panels, somewhere in the compartment and/or the owner's manual to see what 5 red flashes indicates. Check to see if there is 24VAC to the heating wire (White) from the thermostat.

viveen

Thanks
This problem might be beyond my talents.
With the thermostat off the aircirc fan and inducer fan runs continually.
When you shut down power to furnace everything shuts down.
When you turn on the power the inducer fan and circ fan starts running without any call for cooling from the thermostat. It even does it with the thermostat removed and wires just hanging out the wall.
If you lower the thermostat the hvac starts up and cools like normal with the both fans running.
The five errror flashes signify rollout or open auxiliry limit switch.
I just do not know why this would make the circ fan run continously.
I seem to understand if there is a problem with the roll out switch the inducer fan will run??

kok328

Your looking at one of two problems.
1. The rollout switch is tirpped and/or bad but, possibly has a manual reset on it. This may be the type with a small red button in the middle and all you have to do it press it back in. The other types requires replacement.

2. You have a stuck relay on the circuit board and possibly a light tap will unstick it.
If that doesn't work then replacement of the relay is in order.

Don't call an HVAC tech as they will not do in-the-field board repairs and will charge you for a replacement board to correct a simple relay problem.