How to Find and Fix a Hot Tub Leak

What You'll Need
Pump wet end seal
Heater assembly manifold
Slice/knife and gate valves
Plumbing tubing
Jet bodies
Acrylic spa shell
Basic tool set (including wrenches)

A hot tub leak can become an extremely frustrating problem, as leaks (especially small ones) are quite hard to locate. And of course, the leak isn’t getting fixed if you can’t find it. Here are some basic troubleshooting steps for how to locate your leak and repair it.

Note: Not all of the materials listed will be needed. This list mostly makes up the various hot tub components that may need replacing in order to stop your leak.

Step 1 – The Pump

The pump is one of the most common places for a leak. Turn off the power and check under the pump for leaking water. If you find it here, you may need to replace either the pump itself or the pump seal.

Step 2 – Union Fittings

The next thing to check is union fittings located around the pump and heater, as they can come unfastened rather easily. Even on new hot tubs, there is a chance that they’ll vibrate loose in shipment. If the union fittings are loose, tighten them by hand. Never tighten spa unions with a wrench!

Step 3 – The Heater

The next thing to check is the heater assembly manifold, consisting of the heater, pressure switch, and other surrounding components. Replace any parts necessary to fix a leak here.

Step 4 – Valves

Inspect all valves for leaks. On knife style valves, there is a gasket between two halves bolted together, which can fail and cause leakage. Also, some hot tubs have valves installed on either side of the pump so that water doesn’t need to be shut off or drained in order to replace or fix the pump. However, these are actually a very common cause for leaks and are often removed entirely after the first issue.

Step 5 – Connections

Move on to checking all pipes, jets, and connections. Some connections can be tightened or sealed while leaking jets might have a failing gasket inside that will need replacing. In the case of PVC-type pipes that have cracks or holes, use a product called Plast-Aid to fix them. This is a molecular bonding component that actually hardens stronger than the PVC itself.

Step 6 – The Shell

Modern shells are made from such strong fiberglass combined with other layers that if there is a shell leak, it is usually a problem with one of the jets or other attaching components instead. If you do have a shell leak though, Plast-Aid can be used to fix it as well.

Step 7 – Other Location Methods

If a visual inspection of all the components doesn’t turn up anything, there are a few other methods. For example, if the leak is substantial but for some reason you can’t find it, try putting small amounts of dark-colored dye (food coloring will work) in the water and watch where it leaks to. This also works if there is a leak but the area around your hot tub is constantly wet from other factors; look for the puddle distinguished by the dye.

As a last ditch method, let your hot tub continue to drain without refilling it. At least once a day, mark the level of the water. Once the water stops draining, you know that the water level has fallen below the location of the leak.