When either the timer trips on or I press the pump switch, no water is moving, but the pump is humming, like it might be hung up or siezed. It doesn't trip the gfi if its the timer, but will trip in time on the pump switch. Here's the weird part, its maintaining temp! How can it do this if its not circulating water.I know I should shut it off and drain it but its been in the 20's for a few days and I'm afraid of it freezing and causing more damage. Any help with shortcuts to the problem would be greatly appreciated. While I've got your attention, will the pump or relays catch on fire if this goes for too long? I haven't been in the tub for weeks and just noticed it yesterday. Thanks, Chris

I would guess you have an older 110V spa?

You might find that you have more than the one pump. You should have a small circulation pump that is what circulates the water through the heater to keep the tub at temperature. That pump is aparently working properly. However, your jet pump is what is causing your no circulation and hum, most likely due to being froze. Yes, it is possible to have hot water in your tub and a frozen pump. The circulation pump does not use the complete plumbing as the main pump does. At this moment, I have the same problem with one of my tubs. It is keeping temperature, but if the timer kicks on or if I turn on the jets, the motor just hums, just like you described. If you are lucky, you won't have any severe damage to the plumbing or the motor itself, due to freezing. To check for sure, touch the pump housing for a few. It will be obviously cold if it is frozen. If not, you may have a siezed bearing, but I would suspect ice. You can try to thaw it out but until the temperature gets above freezing agian, you may be out of luck.

One more note. I would make sure your timer is not cycling on until you have remedied the problem, otherwise you run the risk of burning up your main jet motor. You don't want to be running this if it can not turn. Most timers have little pin like objects that you move in and out around the circumfrence of the dial, and you should move them to the "off" position.