We just moved into a home with an inground pool and had the pump motor
sieze up in the last couple days. We're a bit new at the pool thing
and I'm looking for a little help (calculation) determining what size
pump I would need to buy as a replacement. The current one appears to
be a 1.5 HP AO Smith (USQ1102). The pool is about 15' X 25' with depth
from 3' to 5' and is self-cleaning.
I'd also be interested in recommendations on models, particularily
high efficient and quiet, as well as vendors.
Thanks much for the input.
It is a fairly complex thing to size a pool pump properly. This really depends
on the sum of the suction and return head and the amount of water you are
turning over. Without those numbers you are probably stuck with simply trusting
that the original installer was right and use a pump with the same performance.
Here are a couple sites I came up with when I was designing my pool
If you are somewhat handy you can probably rebuild your existing pump for about
a tenth of what a new one costs. Get a seal kit and the bearings from a pump
parts house. It is usually only a few screws to get them apart. 4 long screws
holds the motor bells on and a few more bolts hold the pump itself to the
bell. Be aware the impeller may have backward threads. You will turn it in the
direction of rotation to remove it. There is a screwdriver slot or hex on the
opposite end of the motor shaft to hold it while you loosen the impeller
Typically when the motor bearings fail in a pool pump, the rest of the
motor is corroded to the point of not being worth repair, so you likely
should replace the whole motor, although the pump mechanism may be
Talk to friends and see if there is a pool shop near by. Not one of the
I had one in Tempe AZ called B&B Pools. A friend turned me on to it and they
never steered me wrong. When my motor lunched I took it in to get rewound.
They condemned it and sold me an smaller motor that fit the pump I had. The
new motor used less amps and work solidly until I sold the home.
Usually you replace like for like hp wise. Better check the impellers on
the pump for wear. You might need an complete new set up.
pools "The hole in the water where all the money goes."
On 22 Aug 2004 06:34:20 -0700, firstname.lastname@example.org (Uncle Milty)
Stick with the same HP pump you already have. If you pull the
pump/impeller assembly off the back of the pump housing and take it to
your local pool place. They will usually pull the impeller and swap
the motor for you at no charge (other than the new motor).
A pool pump is pretty much a pool pump. X horsepower motor uses X
amount of electricity.
On Sun, 22 Aug 2004 23:45:55 -0500, Richard J Kinch
The motor can't see what its connected to so it is just as efficent
when connected to a pool pump as it is if its connected to any other
device. Larger pumps may be less efficient than smaller ones but
since the OP was trying to save money if possible I think we are safe
to assume he isn't going to replace his 1.5HP motor with a 5HP unit.
I was wrong in one respect. A.O. Smith does have an energy efficient
motor that, in the 1.5hp size, could save the OP around $40 per year
and only cost about $50 more than the standard motor. I have reached
the limits of my meager knowledge here and have no idea how they
accomplish the added efficency. Details available at
Understand that PER GALLON PUMPED a smaller pool pump is more efficient
than a larger one. Thus you want the SMALLEST pump that will do the job.
The job in a pool is mere circulation of some number of gallons per day.
Pressure and flow are themselves not the job. Oversizing is very, very
costly in the long run.
Pool pumps are typically wrongly oversized, a very costly thing over time.
The wrong $100 motor can cost you $1000s in wasted power.
You probably want 1.0 HP or even smaller for your size pool. It's not as
complicated as the trade likes to pretend; it does come down to only 2 or 3
possible choices. Smaller is better as long as you get the job done.
Lots of pool pump motor sellers on eBay. Email them if they don't list
what you need. Local shops may or may not give you a good price.
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