If you own an inground pool in California and the pump or its motor dies, the replacement has to be variable-speed. Two sets of rules took effect on July 19, 2021. A federal Department of Energy standard covers new pool pumps, and California's Title 20 covers replacement motors. Nobody will make you pull out a single-speed pump that still runs. When it fails, though, you can't put another one back.
What do the rules require?
The federal standard sets efficiency levels for dedicated-purpose pool pumps, the self-priming filter pumps that sit on most inground equipment pads. In practice, only variable-speed models meet those levels at the common sizes. Smaller pumps face looser limits.
The federal rule left a gap: you could still swap just the motor on an old pump body. California closed it. Under Title 20, a replacement pool pump motor rated from 0.5 to 5 total horsepower and built on or after July 19, 2021 must be variable-speed. Its default speed can't run higher than half its top speed, so the motor starts out in the low, efficient range.
The rules bind manufacturers and sellers. You'll feel them at the parts counter, when the single-speed motor you used to buy isn't on the shelf anymore.
Why does a slower pump use so much less power?
Pump physics works in your favor. Flow drops in step with speed, but power drops much faster, with the cube of speed. On paper, a pump at half speed moves half the water for about an eighth of the power. Real motors and real plumbing lose some of that, and the gap still stays wide.
A single-speed pump has one setting: full. A variable-speed pump lets you run long and slow for filtration, then speed up only when a job needs it. We covered how to size the daily run time in How Long to Run Your Pool Pump in a Marin Summer. A variable-speed pump makes the longer schedules in that post cheap to keep.
What changes for a Marin pool?
- Your PG&E rate. Many Marin homes pay time-of-use rates, with the highest prices in the late afternoon and evening. A variable-speed pump can do its slow run in the cheaper hours and stay off or near idle through the peak.
- Noise. At low speed these pumps run quiet. On tight lots in Sausalito, Tiburon, and Mill Valley, where the equipment pad sits near a bedroom window or the neighbor's deck, you'll notice.
- Debris. Under the oaks in San Anselmo and Fairfax, or the redwoods in Larkspur, the base speed has to stay high enough for the skimmer to pull leaves and needles off the surface. Set it too low and the debris sinks.
- Older pads. Plenty of pools in San Rafael and Novato still run original equipment on mechanical timers. A new variable-speed pump needs its own schedule, either from its onboard controls or from your automation system.
Should you replace a single-speed pump that still works?
You don't have to. Look at the pump's age, how loud it runs, and what your electric bill shows for the hours it's on. A tired single-speed pump that hums all afternoon in Novato heat is a good candidate. A newer one on a short fog-belt schedule may earn less back.
If the motor fails, price a whole new pump next to a motor-only swap. A variable-speed motor on an old, cracked pump body can cost you a second repair soon after the first.
What should you set after it's installed?
The factory settings get you running. They don't fit your pool yet. Dial in these four things:
- A base filtration speed that keeps the skimmer pulling.
- A higher speed block for your pool cleaner, if it runs off the pump.
- Enough flow for the heater to fire and the salt cell's flow switch to close.
- A spa spillover or water feature boost, on its own schedule.
We replace pumps and motors and program them for the pool they're on. See our repair service for the rest of what we fix at the equipment pad.
If your pump is failing or you want to know whether a variable-speed upgrade makes sense for your yard, call us at (415) 562-8143. You can also send a request and we'll get back to you.