Hot Tub Leaks – How to Find and Stop Them

Eventually, all hot tub owners have to deal with spa leaks. Finding and fixing them is a breeze, if you know where to look.

Finding leaks

After turning off the power, open the equipment compartment and look for obvious leaks or pooling. On spas with foam-filled cabinets, dig away the soggy foam until you find the leak source.

Another method is to fill your hot tub (with the power off) and let the water drop. Once the water stops draining, examine jets and parts just above the new water level for leaks.

If the water drops to the bottom of the tub, the problem may be a water intake or light assembly

What are the most common leak sources?

Leaks commonly stem from the following areas or parts:

  • Pumps
  • Heater
  • PVC Pipe Connections & Unions
  • Valves
  • Jets & Manifolds


Pay close attention to the pumps. Pumps run under high pressure, and water will leak past worn out seals. Signs of a leaking seal are water under the pump and water spots or rust on the motor.

Changing the seal,  wet end, or complete pump assembly is required when a pump seal fails. On older pumps, change the complete pump and motor, rather than just individual parts.

New pumps come with a warranty & new seals. You’ll save much more money vs. buying each part as the other parts fail.


Heaters leak from plumbing unions, sensors or pressure switches. Rust on the heater tube is a sign of a heater leak.

Leak repair on a heater is as simple as changing the  union gaskets  or  pressure switch. Replace the
heater assembly if it has corrosion or pitting. Those areas will become a leak source in the future.

PVC Connections & Unions

Unions are prone to loosening with vibration and changes in water temp. Hand tighten leaking unions. If they keep leaking, try changing the gasket, O-Ring, or the union assembly.

Tighten hot tub plumbing components by hand only. Since they are plastic, they will break if you use tools.

Glued plumbing parts are more difficult to seal. Try these fixes before cutting out and changing plumbing parts:

  • A leak patch kit repairs cracks in hard surfaces like PVC and spa shells for good, and installs like a sticker.
  • Pour in liquids seal minor plumbing leaks. These are great to try if you cannot find the source of a leak. Note: Pour in leak sealers cannot cure leaking pump seals.

If the leak can’t be repaired with these methods, cut out the leaking plumbing and change the parts.


Hot tubs use 3 basic valve types:  shutoff valves,  diverter valves, and air control valves. Shutoff and diverter valves are more prone to leak than air control valves, as they control water flow, not air.

Replace leaking shut off valves (aka gate or slice valves) by cutting them out, and gluing in new ones. These valves stop water flow in order to service equipment without having to drain the spa. For a quick & easy fix, change the valve out for a straight section of PVC and remove the valve entirely.

Diverter valves leak because of worn out or dry O-Rings. Keep valves leak free and working smoothly by greasing O-Rings and any moving surfaces inside.

Jets & Manifolds

Do you think you have a shell leak? A jet gasket leak is much more likely. Jets have flexible gaskets that seal against the spa shell. Over time, hot tub water breaks down the gaskets, causing leaks.

To fix a jet gasket leak, you’ll need to remove the jet from the spa to access the gasket. The spa shell and jet must be clean before installing a new gasket. Use silicone sealant on both sides of the new gasket before tightening the jet to create a better seal.

Jet manifold damage occurs when water freezes inside the plumbing. SpaBond or Plast-Aid will fix smaller cracks. If the manifold is beyond repair, it has to be changed.

Start by cutting out the manifold and any elbows attached to it. Replace the parts and glue everything back into position.

Shell Cracks

While it is rare the spa shell itself would leak, it is possible. Most blisters or surface cracks in the acrylic layer of the shell are only cosmetic, and rarely cause leaks.

To repair surface cracks, drill a small hole (1/16” or less) on either end of the crack to prevent spreading. Thoroughly clean the surface around the crack, and apply either a patch or, for larger cracks, Plast-Aid.

Leak Prevention

An ounce of prevention is worth a pound of cure. Keep an eye out for leaks on a regular basis. Fixing leaks right away makes repairs much easier.

At every water change, open the equipment cabinet and look for signs of water. Double-check all unions. Are they tight and dry?

Pay special attention to the pump. Watch out for any signs of water on the motor, such as rust or water spots. Signs of water on the pump or motor is commonly the result of a leaking seal.

Keep spa water properly balanced and sanitized. Low pH and high bromine/chlorine levels cause equipment problems and leaks over time.

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