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Hot tub leak repair: find it first, then decide
A tub that needs topping up every few days has a leak, and the whole job is finding it. Where the water is going decides whether this is a $300 union or a foam dig. Here is how we work it out, and what the answer tends to cost in Connecticut.
First, is it a leak at all?
A covered tub in Connecticut loses roughly an inch a week to evaporation in winter, more with a tired cover and more still if the cover is left off on cold nights. Splash-out from a family of four adds to it. If you are topping up an inch a week, that may be normal. An inch a day is a leak.
The bucket test: fill a bucket with tub water, set it on the top step so the water levels match, mark both, and wait 24 hours with the cover on and the tub running. If the tub drops more than the bucket, it is leaking.
Where hot tub leaks come from
- Pump shaft seal. The most common. Water drips from the pump between the motor and the wet end. Seal $250 to $400; whole pump $450 to $900 if the motor bearings have taken on water.
- Heater unions and manifold fittings. The big nuts on either end of the heater tube loosen with heat cycling. Often a tighten and a new gasket on the diagnostic visit.
- Slice valves and drain valves. Gate valves weep from the stem; drain valves get left slightly open.
- Jet bodies and PVC glue joints. Behind the shell, inside the foam. These need the leak located precisely before any cutting.
- Light lens and shell fittings. The underwater light gasket is a classic slow leak.
- Shell cracks. Rare on acrylic shells unless the tub froze. Repairable from the top in some cases.
How we find it
Equipment bay first, with the pumps running and then stopped, because some leaks only show under pressure and some only show at rest. Then dye at the jets and fittings from inside the tub. If nothing shows, the water level test: let the tub leak and stop topping up; the level it settles at tells us the height of the leak, which narrows the search to one band of plumbing behind the shell. Foam is cut only when we know where.
What it costs
| Leak | Typical repair |
|---|---|
| Union, fitting or valve in the equipment bay | $150 – $350 |
| Pump shaft seal | $250 – $400 |
| Pump replacement | $450 – $900 |
| Jet body or glue joint, foam dig, repack | $400 – $900 |
| Light lens gasket | $150 – $300 |
| Shell crack, from above | quoted after inspection |
Ranges are orientation. The diagnostic visit ($125 to $175) covers the search; the repair is priced in writing once the leak is found.
When a leak is not worth chasing
A full-foam tub over 15 years old with a leak deep behind the shell can cost more to open up than the tub is worth. We will say so. Sometimes the right answer is a cup of leak sealer and a plan to replace the tub in a couple of seasons, and we would rather tell you that than cut foam you are paying for.