I have a Laing SM-1252-NTW-24 pump and I think it is faulty. It's a single speed circulation pump. On powering up it runs fine and pumps water through well. After a few hours the flow rate drops to nearly nothing, the pump sounds different and gets very hot. Then the heater of course cuts out.

I'm not familiar with these but have taken it apart. The wet end rotor looks good and clean, and there's no leaks. I can run it in my hand and the impeller spins fast, is it really supposed to be so loose? If I run it on it's side as it would be in when connected the impeller does wobble. Perhaps this is because it has no water running through?

Anyway, does it sounds like a pump fault? If so is it the motor or the impeller? I have seen rebuild kits but not for the SM-1252 model. I'm in the UK but can ship to the States as I have relatives over there. I've seen a complete new pump for $250 but that's too much for me.

Please help, my kids have been nagging me to sort this for months!!