We have a built in hot tub with our pool, and recently have had problems with our air blower tripping off a few minutes after starting. It used to run much longer (1/2 hour or more), but now struggles to last 3 minutes. We just replaced the blower in kind with a new 2 HP motor (same HP as previous), and it still has the exact same problem. It trips off due to the high temperature protection switch on the motor. It doesn't appear to be a check valve problem.

If you run the tub without the circulating water (circulating pump off, so only air comes through the jets, no water stream), the blower will run an hour or longer without overheating. The problem in running in this 'mode' is the air from the jets just bubbles up the side of the tub (no water in the jet to entrain the air into the center of the tub) and in addition to splashing us in the face constantly it blows out alot of water out of the tub after several minutes, so it isn't enjoyable.

If you run with the circulating pump on, the blower and pump seem to run nice together, but than you hear the blower start to 'surge' after a few mintues and then the air blower overheats and shuts off and is inoperable for about an hour. Also, of the 4 jets in the tub, only 3 work with the circulating pump on but all 4 work with the circulating pump off. It seems to me that the water pump (when running) overpowers the blower and the blower doesn't provide enough head to pressure its way into the jet when the pump is running, and thus we need a larger blower. A technician we've had out indicated the opposite, that the water pump can't entrain enough air in the jet, and that the air line backs up and as a result the blower overheats. He thinks we should try a smaller blower (maybe 1 or 1.5 HP instead of 2 HP because we only have 4 jets). But he isn't sure.

My questions are:

1. Should I try a larger or smaller blower? Is the problem the blower doesn't provide enough head to get into the jet with the water pump running, or is it the opposite where the blower provides too much air that the water pump can't entrain it all in the jet and is causing the blower to overheat?

2. Is the problem even the blower? Could the jets (air intake holes) be clogged? If so, how can I check, and better how can I clean the jets without having to dismantle the tub? Is there a special tool or something to clean the jets?

3. If the pump is overpowering the blower so air can't get in through the jet, would installing a throttling valve on the circulating pump discharge line (to lower the circulating water flow and pump outlet pressure) help restore the balance so the blower can pressure into the tub? I think the pump is a 1.5 HP. Or would this damage the pump?

I am new to hot tubs and pools, so any help is appreciated.
Thanks!

As long as it's plumbed properly, a larger, more powerfull blower motor should help solve your problem " title="Smile" />