My problem I believe is with the blower control on a heat pump. With the thermostat in COOL or AUTO, the outdoor unit stops as expected when the temperature setpoint is reached. But the blower does not stop running. It continues to run as if it's in a manual run control. If the breaker to blower unit is switched off and back on, the blower stops and will not run until the thermostat calls for the outdoor unit to turn on again, then the blower is back on and won't turn off again.
The blower speed is higher when the outdoor unit is running but I think this is normal.
Where should I start looking to troubleshoot this? It's run all summer this way - mainly because the system did continue to cool and the service guys are all so swamped.
Any advise received will be appreciated.
Thanks,
Don

What type of system do you have and how old is it.

First of all, thank you for your consideration on my question. To answer your question, I have listed below all the components of my system the best that I can tell:
(1) outdoor heat pump: International Comfort Products model NHP042ACC2. This unit was installed in 2004 and replaced the original heat pump installed with the home.
(1) under the house blower unit: Heil model nos. BH5048SKA1, H2B548A3S1. 1/2 HP.
(1) Carrier Weathermaker Two-Zone controller installed at the blower unit.
(2) indoor Totaline digital/non programmable thermostats

Please let me know if there is any additional information that's needed. Thanks, Don

T-Top. Sorry I negleted to includes how old the other components of the system are. The heat pump was installed in 2004 but all the remaining components were installed (I assume) in 1993.

So the entire system, excluding the heat pump, is 14 yrs old.
Thanks, Don

It sounds like you have a fan relay that is sticking closed, if you have a volt meter you could check this and see if it has voltage on the contacts of the coil when this is happening, if not then replace the relay. Good luck, Mike