6 min read · TopTubs Lincolnshire Ltd
A leaking hot tub is stressful — but most leaks are fixable without replacing the tub. The key is finding exactly where the water is coming from before attempting any repair. Here's a systematic approach.
Hot tubs lose water through evaporation — particularly in warm weather or when the cover is left off. A rough guide: a tub should not lose more than 2–3cm of water per week through evaporation alone. More than this, and you likely have a leak.
Carry out a simple test: mark the water level with tape, turn off the jets and circulation for 24 hours, and measure the drop. Compare this with the jets running. If you lose more water with jets on, the leak is likely on the pressure side (jets, pipes, pump seals). If the rate is similar, it's more likely gravity-fed (shell, fittings, drain valve).
The most common leak point. The rubber gasket behind the jet body compresses over time and allows water to seep through. You can often see watermarks or mineral deposits on the cabinet exterior below a leaking jet. Replacing the gasket is a DIY job with the tub drained.
Unions are the threaded connectors that join pipes to equipment. They rely on an O-ring seal that can degrade. A weeping union fitting often leaves a watermark or limescale trail. Usually fixable by tightening the union or replacing the O-ring.
Acrylic cracks are unusual but possible — usually from impact damage or stress cracking around fittings. Small cracks can be repaired with an acrylic repair kit. Larger cracks or those at stress points need professional assessment.
The threaded drain fitting at the base of the tub can weep if the sealant has degraded. Usually fixable with PTFE tape and thread sealant with the tub drained.
Mechanical seals on wet-end pumps fail over time — typically after 3–7 years of use. A failed pump seal leaks from inside the equipment bay. You'll see water pooling beneath the pump. A seal replacement requires the tub to be drained and the pump to be partially disassembled.
Use food colouring to locate a leak. Squirt a small amount near a suspected joint with the jets off. If it's drawn towards a gap, you've found the source.
Most leaks are repairable on-site without replacing major components. Call us and describe what you've observed — we can often advise remotely whether it's a DIY fix or needs a visit.