Hayward TriStar VS

The TriStar VS comes in two sizes and Hayward documents them as two families: 1.85 THP and 2.70 THP, the latter sold as the TriStar VS 950.

What is worth knowing before you order a part: the two are the same pump except for two components. Housing, basket, lid, diffuser, seal plate, shaft seal, every o-ring and every bolt carry the same number across both. The only things that differ are the impeller — SPX3210C against SPX3220C — and the drive and motor assembly.

That makes most TriStar VS parts easy to get right and exactly two of them easy to get wrong, and the two that differ are the two that matter.

One model, several numbers

The same pump is sold under different part numbers depending on where it goes and what is built into it. For the 2.70:

• SP32950VSP — TriStar VS 950, the standard dealer number
• W3SP3206VSP — Open Line, approved for online sale on shorter warranty terms
• SP3206VSPBH — the bare pump
• HL32950VSP — the Omni version, with automation built in
• HCP2500VSP — the commercial variant

The 1.85 follows the same pattern: SP32900VSP, W3SP3202VSP, SP3202VSPBH, HL32900VSP.

They are all in one manual, and they all take the same parts. The Hayward brand page explains what the W3 prefix costs you in coverage.

Hayward's newer TriStar VS 800 Series is a separate line with OmniX built in, in 1.25, 1.85 and 2.25 THP. It shares this pump's housing, lid, basket, diffuser, seal plate and shaft seal, and its 1.85 THP model takes the same SPX3210C impeller, but it has its own power ends and manual.

On 115 volts it is a smaller pump

Both sizes run on 115 volts as well as 230. Hayward's product pages say so, but not how much of the pump you give up. Hayward's curve sheet does. It draws each size twice, once for each voltage:

• 2.70 THP: on 115 V it matches 230 V only up to about 30 GPM, then falls away, reaching about 102 GPM at 30 feet of head instead of 172.
• 1.85 THP: it leaves the 230-volt curve at about 10 GPM and reaches about 58 GPM at 30 feet instead of 122.

ENERGY STAR lists each voltage separately. It rates the 2.70 at 1.5 total horsepower on 115 V, and the 1.85 at 0.85. Hydraulic horsepower, the pump's output at full speed on the federal test's standard plumbing curve, falls by more than half on both: 1.817 to 0.881 on the 2.70, and 1.240 to 0.448 on the 1.85.

Filtering at low speed is not affected. At ENERGY STAR's low test point, around 31 GPM, the 2.70 draws 121 watts on 115 V and 117 on 230. The loss is at the top end, in the jobs you bought a big pump for: backwashing, spa jets, a suction cleaner.

Hayward's spec tables make 115 volts look better, not worse: WEF 12.9 against 8.3 on the 1.85, and 10.1 against 7.3 on the 2.70. That is the test, not the pump. The federal test sets a variable-speed pump's high test point from its own top flow, and its low one from its rated output. ENERGY STAR's listing puts the 1.85's test points at 25 and 48 GPM on 115 V, against 31 and 68 on 230. Slower points cost less per gallon, so the shrunken pump scores better.

If your pad is 115 volts and staying that way, size from the 115-volt curve rather than the name on the box, or pick a pump that keeps its output there. The TriStar VS 800's 1.85 THP takes this pump's 1.85 impeller, and ENERGY STAR lists it at the same output on both voltages. So does the Jandy VS FloPro in its 1.3 and 1.65 HP sizes.

The impeller screw is a left-hand thread

This is the single most useful sentence in the manual, and it is easy to miss.

Hayward's instruction: "Rotate the impeller screw clockwise (note that screw has left-hand thread) and remove." Going the way you would expect tightens it, and people snap them.

Reassembly is the mirror image — the impeller screws onto the shaft clockwise, the impeller screw goes in counter-clockwise. Hold the motor shaft with a 5/16 inch hex wrench in the socket at the back while you do either.

The rest of the seal job is documented with item numbers in the manual, and two figures are worth having in advance. The six housing bolts are 5/16 by 2 inch, taking a ½ inch wrench, and they go back to 185 inch-pounds, tightened alternately and evenly to the torque pattern in the book. The four motor bolts are 3/8 by 1 inch on a 9/16 wrench.

Date the pump before you order

The serial number is 17 digits, and the fifth to eighth are the year and month of manufacture. On Hayward's own example — 21122305456789001 — that reads as the fifth month of 2023.

Worth doing before ordering anything, because part numbers on pool equipment move with manufacturing dates far more often than people expect, and it takes ten seconds off the nameplate.

Pipe size sets the ceiling, not the pump

Hayward publishes maximum system flow by pipe size, and it is the number that should shape the schedule rather than the pump's rating:

• 1½ inch — 45 GPM
• 2 inch — 80 GPM
• 2½ inch — 110 GPM
• 3 inch — 160 GPM

Those work out at roughly 6.9 to 7.6 feet per second, which is below the 8 fps figure usually quoted as the code ceiling. Hayward is being conservative on purpose, and the conservative number is the one to design to. The pump sizing guide works through why velocity rather than horsepower is the real constraint.

Hayward also asks for five pipe diameters of straight pipe between the suction inlet and the nearest elbow or valve — 10 inches on 2 inch pipe. An elbow tight against the inlet makes the pump noisier and the flow worse, and it is the most common plumbing shortcut on a retrofit.

What variable speed is actually for

A TriStar VS is not a faster pump. It is a pump that can run slowly, and the whole saving lives in that.

Flow scales with speed while power falls much faster. The textbook says half the speed takes an eighth of the power, so twice the run time moves the same water for a quarter of the energy. Real pumps fall short of that at low speed. The running cost calculator uses a pump drawing 320 watts at 1,750 RPM, which moves the same water for about a third of a single-speed pump's energy, and does the arithmetic against your own electricity rate. On its example, $0.17 a kWh over a five-month season, a $1,600 pump takes about six seasons to pay back before any rebate.

Two things spoil it. A pump left on a high default captures almost none of the saving — this is the most common way a variable-speed pump disappoints, and it is a programming problem rather than a hardware one. And other equipment has minimum flow requirements: a MasterTemp heater will not fire below 40 GPM on the 400, and a salt cell may sit partly full of air at low speed and quietly underproduce. Set a low speed for filtering and a higher one for whatever else has to run.

Two ways to void the warranty

Hayward states both in the manual rather than burying them.

Non-Hayward replacement parts void it. That is standard language, but it is worth knowing before fitting a generic seal.

Letting the pump freeze with water in it voids it too. The winterizing instruction is to drop the water below all inlets, pull both drain plugs and the strainer cover, disconnect the pump, then refit the cover and plugs once it has drained and store it dry. If antifreeze is used anywhere in the system it must be propylene glycol — the manual is explicit that other antifreezes are toxic and attack plastic components.

Do not wrap a stored pump in plastic, either. It traps condensation against the motor, which is the thing you were trying to protect.