Hayward pump union threads same as Extreme power?


Active member
Aug 24, 2020
central fla
I have a 10 year old Hayward Tristar 1hp 1.85 sf currently in use but want to pull and set aside for a spare. I would like to be able to slide in a 2 speed Xtreme Power without any replumbing...hoping union threads from existing will screw right on to the Xtreme power pump. FYI both pumps are 2" pipe.


Bronze Supporter
Jul 16, 2018
Milton DE
I didn't take measurements, but I have a Sta-Rite (Pentair) Dynamo 1.5 single speed. I bought an ExtremePowerUS 1.5 two speed to take advantage of having two speeds and have my current pump as a spare on hand. This was the only 2 speed pump I could find this summer. It took a month to get it. Anyway, the outlet union threads were about 1/4 inch larger than my current pump and I had to use the internal threads to connect it. That was "bummer" no. 1 because I had hoped to be able to quick swap them if I ever had a problem.

Additional "bummers": When I disconnected my Sta-Rite, the gauge read 7 PSI. The XPUS read only 4 PSI on high speed. I was expecting the same 7 PSI. On low speed it squealed like it had bad bearings. I reinstalled my Sta-Rite and the gauge again read 7 PSI.

I returned it of course and more carefully read XPUS reviews after that and saw quite a few "died after a month" type reviews. The price was very low, but it seems the quality may match that low price. I also remember reading in at least one review a comment about the odd union thread size.
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Gold Supporter
LifeTime Supporter
TFP Guide
Jul 3, 2013
Fletcher, OK
If the pump end is still good you could reuse it, get a repair kit and throw a V Green motor on there and have a VSP motor... then you would not have to change any pipes or fittings and still have the motor for backup :)

You will need to find the correct fit for your flange ( round or square) but the 1.67 motor would be a perfect fit for your pump end..