Goodman Air Handler - Heaters Don't Work

Goodman Air Handler

Re: Aux Heaters Not Working

Many older Goodman Air Handlers use "Warren" heater kits that utilize DC voltage relays and multiple, small snap-disc limits for heater control and a SPDT sequencer for fan control.

• It is very common for these components to fail and it is very difficult to find replacement parts.

Possible Causes (From Most to Least Likely):

1. Bad Relay(s) (or conversion board)
2. Bad Limit(s)
3. Mis-Wired Low Voltage
4. Bad Breaker(s)
5. Bad Heater(s)

Relays

The Warren heat kit uses black, DC voltage relays with an AC to DC conversion board that plugs into the top of the relay.

• These relays can be replace with a standard sequencer.
  • Discard the AC to DC conversion board and connect the low voltage wires (Blue & White or Brown) directly to the sequencer heater.
    • Will likely require using larger spade terminals.

Limits

The "Blue" Common wire for the heat relays wires in series from the transformer through each limit, so any tripped or bad limit will de-energize all heat relays.

• The limits are typically 170 deg, automatic-reset limits. 
• The limits can be replaced with a standard 3L05-1 or 3L05-3 snap-disc limit, but you have to use a uni-bit to enlarge the hole.
  • Be careful not to drill too deep and hit the heater.

Wiring

There are typically 2 stages of electric heat, "White" wire that goes to one or more relays and a "Brown" wire that goes to the remaining relays.

• In most cases, both the "Brown" and "White" should tie together with the Aux Ht output from the thermostat and defrost board to energize all heating stages together.