Draft Inducer Blower Not Blowing- LED Blinking 3 Times
I have an Amana Gas Fired Furnace Model CCA24FCC. It was part of a new house purchase in 2004. It is located in my garage and shares the venting system with the water heater which is located a few feet away. I hadn't had a need for heating the house until recently as we just a had a cold snap come through Georgia.
The furnace recently started blowing cold air out of the vent registers in the house after a call for heat and would then shut off after a few minutes with the thermostat with setting on "Auto". In the thermostat "ON" setting the circulator fan just blows ambient temperature air.
Upon further investigation I have a blinking LED coming from the circuit board. It blinks three times. The manual says- pressure switch circuit not closed. Exactly! The induced draft blower is not spinning. When a call for heat occurs this fan does not even attempt to spin.
I have verified the pressure switch is functioning- with the furnace off or no movement of the induced draft blower, the switch has no continuity across its terminals. When I pull a slight vacuum on the switch, I can hear it click and then my ohmeter has continuity across it. The problem is the draft motor wont run to pull the vacuum to create the sequence of events to fire the burners.
When the furnace is switched on or a call for heat occurs, there is no voltage at the induced draft blower motor terminals nor do I have voltage at the control unit terminals which lead to the blower.
Am I on the right track to replacing the control unit?
It appears the pressure switch works as designed.
The induced draft blower fan does not have adequate power supply.
Lack of power supply was traced back to the terminals at the circuit board.
I had hoped that there was a relay, breaker or fuse I could replace instead of the entire board, but I am unsure of the next best step.
I live in a townhome and I have the exact same model in my attic which supplies heat to the upstairs. Any suggestions on potential parts swapping to verify failure?
By the way, I had skipped replacing my filters for a few months and they were really dirty when I replaced them today while diagnosing the furnace. I noticed when removing the furnace filter that it looked as though it had a water stain on it. (possibly from condensation of some sort) The circuit board is right above where the stain was located.
Last edited by rust101; 11-28-2009 at 01:44 PM.
Reason: Ease of understanding