Hot Tub Leaking? How to Find and Fix It

A leaking hot tub is frustrating — you're topping up constantly, water bills climb, and if the leak is near the pump, it can cause electrical faults. The first step is finding where the water is escaping. There are only a handful of common leak points.

Step 1: Where Is the Water?

Before you do anything else, observe:

Water around the pump? → Pump seal, hose connection, or internal leak
Water underneath the tub? → Liner puncture, drain valve, or seam failure
Water at hose connections? → Loose fitting or perished seal
Water level drops but no visible water? → Evaporation (normal: 1-2cm per day) or very slow leak

Inflatable Hot Tub Leaks (Lay-Z-Spa, Intex, MSPA)

Punctured Liner

The most common leak on inflatable tubs. Causes: sharp objects underneath, pets, accidental contact with tools or garden furniture, UV degradation over time.

Finding the puncture:

Inflate the tub (without water if possible for the walls)
Mix washing-up liquid with water in a spray bottle
Spray sections of the tub systematically — bubbles will form at the puncture site
Mark the spot with a waterproof pen

Fixing it: PVC puncture repair kits work well on inflatable hot tubs (£10-15). Clean the area with rubbing alcohol, apply the patch according to kit instructions, and let it cure for 24 hours before filling with water. For underwater repairs, there are wet-application patches available.

Hose Connection Leaks

The hoses connecting the pump to the liner have rubber seals at each end. Over time these seals harden, shrink, or crack — especially after winter storage.

Check each connection point for drips while the pump is running
Tighten the connectors (hand-tight plus a quarter turn — don't overtighten)
If tightening doesn't fix it, replace the seal ring (available from the manufacturer or aftermarket, under £5)

Pump Seal Leaks

Water leaking from the pump unit itself usually comes from the internal seals where water enters and exits the pump housing. This can happen from wear, limescale buildup, or thermal cycling (the seals expand and contract with temperature changes).

Signs: Water pooling underneath the pump, water visible where the hoses connect to the pump body.

Pump seal kits are available (£15-30) but require disassembly of the pump — a job for someone comfortable with mechanical work.

Drain Valve Leak

The drain valve at the bottom of the tub can leak if:

It's not fully closed (push and twist firmly)
The O-ring is damaged or missing
The valve housing has cracked

Check the drain first — it's the easiest thing to overlook and the simplest to fix.

Hardshell Hot Tub Leaks

Jet Gasket Leaks

Each jet has a gasket sealing it to the shell. Over time these dry out and shrink. You'll see water weeping around the jet housing.

Replacing jet gaskets is straightforward — remove the jet, replace the O-ring, refit. But if multiple jets are leaking, it suggests the tub shell has shifted or the gaskets are all aged out.

Plumbing Connection Leaks

Hardshell tubs have internal plumbing with unions, glued joints, and flexible pipes. Leaks at union joints can often be tightened. Leaks at glued joints need cutting out and re-plumbing — a professional job.

Shell Crack

Rare but serious. Acrylic shells can crack from ground movement, freezing water (if not winterised properly), or manufacturing defects. Small cracks can be repaired with acrylic repair products; large cracks may mean the shell is done.

💡 Is It Actually a Leak? Hot tubs lose water naturally through evaporation — 1-2cm per day is normal, more in windy or hot conditions. If you're losing more than that, you have a leak. If you're right at that threshold, try the bucket test: fill a bucket to the same level as the tub, place it next to the tub, and check both after 24 hours. If the tub level drops more than the bucket, you have a leak beyond evaporation.

Leak Detection Tips

Food colouring test: Add a few drops near suspected leak points — the dye will be drawn toward the leak
Dry paper test: Place dry paper towels around the base and connections — they'll show exactly where water appears
Run with filter only vs with heat: If the leak only appears when the heater is on, it's likely a seal that expands under heat
Check after rain: Some "leaks" are actually rainwater collecting around the base — drain the ground area and recheck

When to Call an Engineer

DIY is fine for:

Liner puncture repairs (patch kit)
Hose seal replacements
Drain valve fixes

Call a professional for:

Pump internal seal leaks
Hardshell plumbing leaks
Leaks you can't locate
Any leak near electrical components

Can't Find the Leak?

Our local engineers have leak detection experience across all hot tub brands. Save time and water — get it found and fixed properly.

📞 Get a Free Quote