Sta-Rite Max-E-Therm 333 - Knocking Sound-> Shut Off


New member
Jun 10, 2021
Hello All,
I've been reading through posts, and want to thank everyone who is helping guys like me out! It's a real pleasure to find a helpful forum.

I have a Sta-Rite Max-E-Therm 333 Pool/Spa heater which came with the house I purchased in 2019. The heater ran fine all last summer (spa only). I hired a guy to close the pool, and then I opened the pool this spring. Last week I opened the heater, vacuumed/blew it out, checked for animals, etc. All looked good. I turned on the gas, hit the button, and expected all to be fine. It wasn't.

By the sound of it, here is what is going on:
- Power on
- LP Gas flows and ignitor fires (sounds good)
- Blower motor comes on (here's the problem), and it sounds like something is rolling around in there. Sounds like a nut, or broken piece of something flopping around.
- Unit shuts off immediately
- Temperature display shoots up from 70-110+, and then comes right back down
- I didn't see any other LED lights come on.

This is where I stopped. I called Pentair customer support, and the recommended looking at the thermal regulator and the bypass. I want to trust them, but the sound didn't sound like it was coming from the manifold area. Sounds like it is with the blower. I did order the parts from amazon, but they have not arrived yet.

Any help would be highly appreciated!
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