Lay z spa hot tub pump

[UTT]

Hot tub out, cleaned, blown up and filled for summer

Leaking out of bottom of pump/egg. Stripped unit down and replaced seals on pump, new gasket seal and replaced the impellor believing that they are all one size fits all. The hot tub was working while leaking but the pump was quiet noisy, hence hence the new impellor.

New impellor and seals all worked a treat and the pump was running aloft quieter. Switched it off to re-run cable through window and the thing would not start, flashing up error 02 and pump not even starting.

Put old noisy impellor back in and pump fires up fine and back to grinding noise we had before.

I just can't believe that a standard pump impellor can have that effect and one work fine and another not at all when the look almost the same!

Anyone had similar experiences?

 

[Bickaxe]

No, but I did notice water coming out of the unit when we fitted it up last month. It's is now 3 years old.
Will mention this to the missus.

 

[NickK]

It depends on the pump design as the system needs to get the pump impeller spinning the correct direction.

On the old impellers the blades and the magnetic mass span on the shaft but the blades could rotate separately from the mass by a small amount. The idea is that the freedom of movement allowed the mass to get going int the right direction before engaging the blades and moving water. They sound like they're rattling for a second on starting up the pump.

On the newer variable pumps they use phased motors so the pump phases cycle and the pump impeller can only go in that direction to follow the powered phase. These are quiet on start and have a pitched wine that changes with the set pump speed. They use the magnetic pole position on the hall sensors to understand where the impeller is in it's rotation.

I have a 6000lph old style and a 20,000lph variable style.

I suspect that it may be getting confused if it's the latter pump with the former impeller?