Hayward TCELL925 vs. TCELL940: Which Extended Life TurboCell Do You Need?
Salt cells wear out. That's just how they work, and when yours finally quits you have to pick a replacement. If you have a Hayward system, two of the most common choices are the TCELL925 and the TCELL940. They look almost identical sitting on a shelf. The difference is what they're rated to handle.
Here's how to tell which one belongs on your equipment pad.
What's the difference between the TCELL925 and the TCELL940?
Pool size rating. The TCELL925 is built for pools up to 25,000 gallons. The TCELL940 is built for pools up to 40,000 gallons. Same Extended Life TurboCell family, same basic design, different chlorine output.
The TCELL940 has more plate surface area inside the housing, so it produces more chlorine per hour. That's the whole story in one sentence. Everything else about how you install it, clean it, and live with it is the same.
Which one fits your pool?
Start with your actual water volume, not a guess. If your pool holds 25,000 gallons or less, the TCELL925 covers you. If it holds more than that, you need the TCELL940.
If you don't know your gallons, a rough estimate for a rectangular pool is length x width x average depth x 7.5. Round up rather than down. Being a little generous here is safer than coming up short.
A few things that push you toward the larger cell even on a mid-size pool:
- Heavy swimmer load through the summer
- Full sun all day with no shade or cover
- An attached spa that shares the same water
- Hot climates where you run the pool year round
Can you put a TCELL940 on a smaller pool?
Yes, and a lot of people do it on purpose. Running an oversized cell on a smaller pool means it hits your chlorine target faster and spends less time working. Less run time usually means the cell lasts longer before it needs replacing.
The tradeoff is upfront cost. The TCELL940 costs more than the TCELL925. Whether that pays off depends on how long you plan to keep the pool and how hard you run it.
Going the other direction is the mistake to avoid. Putting a TCELL925 on a 35,000 gallon pool means the cell runs flat out trying to keep up, your chlorine still drifts low, and the cell burns through its life early. Undersizing costs more in the long run than buying the right cell the first time.
Will these cells work with your salt system?
The TCELL925 and TCELL940 are the Extended Life TurboCell versions that pair with Hayward's AquaRite 900 series salt systems. Before you order either one, look at the label on your control box and confirm what generation of system you have.
Older AquaRite units and the newer S3 systems use their own cell lineups, and cells are not always swappable across generations even when the plug looks similar. If the model number on your box doesn't clearly match, send us a photo of the label and we'll tell you which cell is correct. That one step saves a lot of return shipping.
How do you know your old cell is actually bad?
Before you buy anything, rule out the cheap stuff. A cell that's not producing chlorine isn't always a dead cell.
- Check your salt level first. Low salt is the most common reason a system stops generating.
- Look inside the cell for white scale on the plates. Scale blocks production and comes off with a proper acid soak.
- Confirm the flow switch is reading correctly. A stuck or failed switch tells the system there's no flow, so it stops making chlorine.
- Check the cell cord and connections for corrosion or a loose plug.
- Note how old the cell is. Most residential cells give you a handful of seasons before output falls off no matter how well you treat them.
If salt is in range, the plates are clean, flow is good, and the cell still won't produce, that's when a TCELL925 or TCELL940 replacement makes sense.
How to make either cell last longer
Keep your water balanced. High calcium hardness and high pH are what build scale on the plates, and scale is what kills cells early. Test regularly and stay on top of pH instead of chasing it after the fact.
Inspect the cell a couple of times a season and rinse it with a hose. Only acid clean when you actually see buildup, because every acid soak takes a little coating off the plates. Cleaning too often shortens the life of the cell you're trying to protect.
In freezing climates, pull the cell for winter and store it somewhere dry. Water left sitting inside a cell through a hard freeze can crack the housing.
TCELL925 or TCELL940: the short answer
Pools up to 25,000 gallons, get the TCELL925. Pools above that, get the TCELL940. If you're right at the line, or your pool takes a beating from sun and swimmers, spend the extra and go with the TCELL940. You'll run it less and it should stick around longer.
Hayward | TCELL925 | Extended Life TurboCell Salt Cell | For Pools up to 25,000 Gallons
$900.00
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Hayward | TCELL940 | Extended Life TurboCell Salt Cell | For Pools up to 40,000 Gallons
$1170.00
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