I have an old Intertherm single outside unit that the blower won't turn off. I had the unit recharged last year for the summer and had no problems until I woke up one morning with air blowing from the vents, not cold, and wouldn't turn off at the wall switch. I had to shut it off at the breaker outside. Turned it on when I got home from work and it ran good, nice and cold until it reached the set temp. The exhaust fan turned off but blower stayed on. Any ideas? Any help would be appreciated.

Is this a package unit? doesn't matter if it is or not, the fan relay points are stuck closed. replace the fan relay.If its a split system attached to a funace inside the house, and you have an electric furnace, then the #1 sequencer could be stuck closed, which would keep the heat speed fan going. I need to know more about the system....donr

This morning, I turned down the thermostat on my ancient (18 yr old) Intertherm, and it too wouldn't shut off until I turned it off from the circuit breaker. Turning down the thermostat did no good; the condensing unit was tick ticking and air still coming out of the vents (but the fan in the condensing unit was not moving). When I turned off the unit from the thermostat, then air still came out of the vents and the condensing unit was still not running except for the tick ticking sound and you could hear the unit struggling/pulsing. I then flipped the breaker and obviously it turned off. When I flipped the switch back, the heater didn't run until I turned it back off, but the same thing again happened. You all are 2 for 2 on my dryer and fridge; I hope you can help me on this one, too.

I still need to know what you have, gas or electric, heat pump etc. donr

Sorry about that; it's an electric heat pump. The condensing unit is outside; the air handler is in the garage. I hope this is enough info.

Thanks!

I'm having a little trouble with the statement " when I flipped the switch back, the heater didn't run until I turned it back off" Are you talking about the electric furnace breaker?? Or you talking about the t-stat?? From the information I'm getting here, it sounds as though your defrost control on the condenser is bad, but I've never heard a heat pump go tick, tick. There could be a short in the 24 volt to the main contactor that might cause it to chatter, but if that were the case, then it wouldn't be laboring. 18 yrs would put it made in the 1989 region, so it wouldn't have a mechanical defrost control. I would say you have a stuck sequencer on the furnace, and a faulty defrost control on the condenser. How does it act in "cool" mode???? donr

Thanks for your patience and sticking with me. I should proofread better . When I turn it off from the thermostat, it kept running, and that's when I got the pulsing/struggling sound. Then, I turned off the circuit breaker and it shut off. When I flipped the circuit breaker back on, the unit was still off. Then, I turned it back on from the thermostat, and got the same results where it would not turn off when I turned down the thermostat and it wouldn't turn off when I turned the unit off at the thermostat. I'll try the A/C and get back to you soon...

Update: I ran the AC and it was pumping cold air. I turned up the thermostat and it turned off just fine.

I just realized I should've replied instead of edited my post...

Update: I ran the AC and it was pumping cold air. I turned up the thermostat and it turned off just fine.

Sounds to me like you caught it in a defrost cycle. If the 24 volts that operates the defrost control comes from the furnace, then it would have continued the defrost cycle when you turned the breaker back on. It's possible you need a new defrost control but I doubt it. When you ran the unit in cool mode, did everything seem to work normal in heat mode after that??? If not, you need to change out the defrost control on the condensing unit. If everything works ok in cool mode, then that rules out a bad condenser motor. If you are up north somewhere, are at least farther north than Texas, I would think the defrost control should be set to where it will defrost every thirty minutes of compressor run time. donr

Donr,
I just ran the heat a minute and turned down the thermostat and she turned off no problem . Do you think it's okay to run now, say overnight, and was just an isolated incident? By the way, I live in Florida, where the low is expected to be 40 tonight.

Thanks!
Mike