Amana Gas Furnace
Re: Lockout
Customer reports that the furnace sometimes stops working. They can get it to work again by turning the thermostat or power off and back on.
To determine the cause of a "lockout", it is important to know which control is installed on the furnace.
Small Control
Most of the older Amana gas furnaces, 80 & 90%, use a small White-Rodgers or Robertshaw Ignition Control.
- The control's primary function is to power the ignitor, energize the gas valve and monitor for flame.
- Therefore, the only real lockout with these controls is a failure to sense flame.
- All other functions (inducer fan, pressure switch, limits, etc) are controlled external of the ignition control.
A diagnostic light on the lower left-hand corner of the board indicates "Lockout" status.
► For Control Replacement, use IGN.02 Universal Hot Surface Ignition Control.
| Possible Causes (From Most to Least Likely): | Qty |
| Dirty Flame Sensor | 1 |
| Failed Glow Plug (usually causes No Heat) | |
| Clogged Burner(s) | |
| Bad Gas Valve | |
| Faulty Control |
Large Control
Newer furnace models started using a White-Rodgers full furnace control board which, like newer furnaces, monitors and controls all functions of heating.
Furnaces equipped with this control can have many lockout conditions.
A diagnostic light in the lower left-hand corner flashes to indicate lockout stats.
- Unfortunately, this board will not store fault codes, nor does it have any means of fault code retrieval, so be careful not to cycle power to the board before looking at the active fault.
See "White-Rodgers Lockout Codes" below for a list of diagnostic indications.
► For Control Replacement, use Honeywell S9200U Universal Furnace Control.