rbeggs

My heater operates normally most of the time except when I turn on the defroster while the heater is in operation. The defroster supplies a blast of increasingly chill air, the windows clear and when the defroster is turned off, only cold air is supplied through the vents. Warm air can be obtained only by turning the heat **** up to full. It seems like a combination of full on-off cycles of the heater **** and/or a shutdown and starting up the next a.m. will bring the heater back to proper functioning. This lasts only till the defroster is activated again.

Anybody else experience this sydrome or have any ideas?

Thanks,

RB