Mom's pump went kaput

[hyperionguy]

Assuming no spa, waterfall, or other water features: you want a 3/4 HP or smaller 1 HP two speed pump. 3/4 HP two speeds are rare, so usually you are forced to get a 1 HP. That will have the lowest lifetime cost and perform well with most pools, including yours.

Jason, I think you just helped answer the question I came out here for. I found out today that Mom's pump went kaput and I am looking into suggesting a 2-speed pump. Currently she has a 3/4 hp single speed Hayward 750 (that has had issues almost every year) for a 15k gallon gunite pool with a Hayward DE-3620 filter. I was thinking that a 2 speed 1 hp sounds about right for helping her save energy while getting circulation for longer periods of time. The pool is 75% shaded all day long by oak trees (shedding stuff) and I don't like the current routine of running 1 12-hour cycle each night (8pm to 8am). Just trying to figure out the Hayward offerings alone is mind boggling. I don't like the stress of making this type of decision under a time pressure.

BTW, I have always been kind of intrigued at the success you've had with 1/2 hp for 19k gallons. That seems low compared to most suggestions I've noticed.

 

[JasonLion]

My 1/2 HP is a WhisperFlo, which means it is actually larger than some of the smallest 1 HP pumps and several of the 3/4 HP pumps. Nameplate HP ratings are more fictional than real. They adjust the HP rating for marketing reasons, so they are not directly comparable. For meaningful comparisons you need to look at SFHP (SF times HP).

Nearly any residential pool is fine with 1/8 HP or less most of the time. The only time you really need something around 1 HP is for vacuuming, priming the pump, and backwashing. That is why two speeds are such a good deal. A 1 HP two speed is 1/8th HP on low speed, which you use nearly all the time, and then you turn it up to high for priming, vacuuming, and backwashing.

 

[hyperionguy]

Thanks for the info Jason.

Turns out that a call to the pool guy went well. There was something either in the line or the impeller. Didn't get a clear story over the phone. So a quick clean out and blow out the lines fixed the flow problem. Circulating like a champ now. Not sure if it's still sounding crummy or not. I didn't ask yet.

The pressure gauge was bouncing up and down 4-5 psi, which from reading out here is sometimes caused by the very problem that was repaired. Good to know for the future.