Equipment
Variable-Speed Pool Pumps in Los Angeles
A slower pump running longer moves the same water for a fraction of the power — which is why California stopped allowing the alternative.
The short answer. A variable-speed pump is the same wet end as any other pump, with a motor you can tell how fast to turn. The saving comes from that one fact, and it is larger than people expect, because power does not fall in step with speed — it falls far faster. Manufacturers put the saving at up to $1,100 a year against a single-speed pump.
That is their figure, not a measurement of your pool. Whether it pays back depends on what you run now, how long it runs, and what your plumbing lets a slow pump do. The cases where it does not pay are below.
Why running slowly for longer costs less
A single-speed pump has one setting: everything. It moves far more water per hour than filtration needs, then stops for the day.
Water moved rises roughly in step with motor speed. Power drawn rises with roughly the cube of speed. Those two lines separate fast, and the gap between them is the argument.
Halve the speed and you move about half the water for an eighth of the power. Run twice as long for the same total volume and you have used roughly a quarter of the energy — same water through the filter, a quarter of the bill.
Which is why this is not a “set to eco and forget” device. Left at full speed all day it saves nothing: the programming is the product.
| Motor speed | Water moved | Power drawn |
|---|---|---|
| 100% | 100% | 100% |
| 75% | ~75% | ~42% |
| 50% | ~50% | ~13% |
| 33% | ~33% | ~4% |
The pump affinity laws, rounded. Real pipework sets a floor below which water stops circulating usefully — but that curve is why the saving is not linear.
What California actually requires
The part that gets repeated wrongly, usually by someone selling a pump this week.
Replacement motors for pool pumps rated at 0.5 total horsepower or more, manufactured on or after 19 July 2021, must be variable speed. The rule is Title 20 of the California Code of Regulations, section 1605.3(g)(6), part of the Appliance Efficiency Regulations administered by the California Energy Commission.
It regulates what may be sold, not what you must own. Nobody has to tear out a single-speed pump that still works. In practice it means that when your pump or its motor fails, whatever replaces it will be variable speed — so the decision gets made on the worst possible day unless you make it earlier.
What changes on the pad
Energy is the headline, not the only difference an owner notices.
- It gets quiet
Most pump noise comes from speed. At filtration speed it is close to inaudible from the house — which matters when the pad sits under a bedroom window or against a neighbour's fence.
- The filter gets more hours
Slow hours are cheap, so there is no reason to ration them. Longer, gentler circulation skims for more of the day and gives algae fewer still hours to establish.
- The motor works less hard
A permanent-magnet motor at a third of capacity runs cooler than an induction motor flat out every afternoon. Bearings and seals are what usually end a pump's life, and both dislike heat.
We install two: the Pentair IntelliFlo3 VSF and the Jandy ePump 2.7 HP. Which suits your pad depends mostly on the automation already there.
When it will not pay for itself
Payback is arithmetic: annual energy saving against installed cost. There are pools where it does not close, and a nearly new pump is one of them — replacing a healthy pump means paying for one you already own. Note too that it will not change what pool service costs, which is priced on the pool, not the pump.
- The pump barely runs
A small pool on a short daily cycle is not spending enough on electricity for a percentage saving to amount to much.
- You already have two speeds
A two-speed pump used properly on low has taken most of the saving already. One speed to variable is a big step; two to variable is a small one.
- The plumbing is undersized
On narrow pipe the low speeds where the saving lives may not move enough water to filter properly. The pump then runs higher, and the saving evaporates.
Three things to check before ordering
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Pipe diameter
A slow pump only saves if water moves freely at slow speeds. Narrow suction lines raise the speed you must run at for the same flow — precisely the saving you were buying.
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Electrical supply
115 V or 230 V at the pad, breaker size, bonding wire. And decide what happens to the old time clock: these pumps schedule themselves, and a mechanical timer cutting power upstream defeats that.
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Automation compatibility
If a controller is meant to drive the pump, the two have to speak to each other. Where they cannot, the pump runs its own schedule while the panel reports it off, and the heater and cleaner stop lining up.
Questions people ask about variable-speed pumps
Should I upgrade my pool pump to variable speed?
If you run a single-speed pump several hours a day and it is getting on in years, the arithmetic usually works — and you will be buying one eventually anyway. If your pump is two-speed, nearly new, or barely runs, the honest answer is often no. Have the existing one looked at first.
How many hours should you run a variable speed pool pump?
Long enough to turn the pool's whole volume over once a day. Because it moves less water per hour at filtration speed, that is a longer run than a single-speed pump needs — often ten to twelve hours or more — and it still costs less. The exact figure depends on your gallons and the flow at the chosen speed.
What is the best way to run a variable speed pool pump?
One long block at low filtration speed, plus short bursts at higher speed only for jobs that need pressure: the cleaner, spa jets, clearing the surface after a windy day. Running all day at high speed is the mistake that turns an efficient pump into an expensive one. Resetting those schedules seasonally is part of weekly service.
What are the disadvantages of a variable speed pool pump?
Three, honestly. It costs more up front. It has a drive and a control board — electronics on a wet outdoor pad, which fail in ways an induction motor cannot. And it has to be programmed: badly set, it saves nothing, and there is no warning light for that.