Just refilled the tub. Turned the heater up. Hit the breaker and it starts to hum along for a minute then cuts out. It will continue with this "on-off" cycle. When it's briefly on. There's no circulation and the blower will sound as if it's working, but no action. So I'm wondering if I have an airlock, or could there be ice in the lines? As I wasn't sure if I drained all the water out of the lines. And it seemed the "t-valves" were froze. Because they wouldn't move in and out. Or would this be syptomatic of a mechanical problem with the pump or heater? Thanks for any help. CK

You didn't describe the actual action of the components enough, but I'll assume that you've gotten some frozen items in there.

If so, then you need to get them thawed out before you do anything else.

Be very careful how you accomplish this...

Just thawed the lines. And still have the problem. However, my blowers work on 1 side. I'm definitley in the dark when it comes to tubs. But this is my analysis. When the temprature is turned up on control panel and tub controls. To activate the heater. A "running" (humming) sound is either coming from the control panel or pump. Like I said I'm in the dark. Anyways, I believe this is normal? As for the heater. I don't even understand its location? So, the "running" will last for a short time, under a minute, and there's no circulation from the jets. Then it clicks off. Which I also can't tell where it's coming from. But I suspect the pump. Then after a minute or two it clicks back on and repeats the process. On the tub controls. The "jets" light is on, actually won't turn off, but there's no jets. From the little knowledge I have of plumbing and electrical work. I understand that to have heat. You must have a pump to circulate that heat. Also, if you refer to my post under "hot tub control problems" forum posted by ck. You will see that prior to this problem. The wire connection between the pump and control panel melted. So I dumped the connection and patched directly wire to wire. Leaving me to guess that the pump needs replaced? Hot or cold anybody? Thanks again, CK