[vjohnson03]

Igniter works fine and fire starts up and heats box then after about 30 seconds or so it shuts down. circulatory fan is free wheeling and hasn't made any strange noises or squeaking sounds. Unit is a Carrier gas fired heater made in 09/93
everything appears clean but fan doesn't come on.

[Kilgen]

Originally Posted by vjohnson03

Igniter works fine and fire starts up and heats box then after about 30 seconds or so it shuts down. circulatory fan is free wheeling and hasn't made any strange noises or squeaking sounds. Unit is a Carrier gas fired heater made in 09/93
everything appears clean but fan doesn't come on.

Try cleaning the flame probe with some fine steel wood. The unit will shut down if flame is not detected. A dirty ( may look clean) probe may be the proble. We have this same problem in a commercial building and must clean the probe every other year.

[vjohnson03]

it turned out to be $193 circuit board. Thank God for good neighbors.