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How To Find And Fix A Hot Tub Leak (6 Likely Reasons)

Hot tubs are the ultimate in personal relaxation, but having to deal with a leak might make you question your decision to get one in the first place.

A hot tub leak is something you need to address quickly and take action to correct before things get out of control.

We’ll help you identify leaks and tell you how to fix them, so you can spend more time enjoying your spa.

What Can Cause A Hot Tub Leak?

There are endless reasons for a leaky hot tub or spa, but the vast majority of issues originate from just a handful of places.

The main culprits are:

  • The pump
  • The heater
  • The lights
  • The valves
  • The hot tub shell
  • The plumbing

How To Find A Leak In A Hot Tub

Hot tubs leaks can come from anywhere, not just the shell itself. In some cases, there may even be multiple leaks at the same time.

To find out where the excess water is coming from, you’ll have to do some inspecting to find the source of the leak. 

How to inspect your tub:

  1. Start by turning off the power to the hot tub. 
  2. Access the equipment compartment by removing the side panels and look for any signs of leaks or dampness. Inspect the pump using a flashlight for greater clarity. Check to make sure the tub’s seals are tight.
  3. Inspect all pipes, fittings, as well as the pressure switch. Ensure there are no leaks at the joints. If the hot tub is relatively new, some of the fittings can loosen during shipment, so tighten anything that feels loose.
  4. Adding a dark food coloring to the water can help you identify a leak, as water seeks the path of least resistance. Following where the darker water first appears should help you determine the leak location.
  5. Try turning off the tub and wait for the water drain out of the leak point. If it eventually levels off, you’ll know the leak is somewhere above where the water levelled out.

How To Fix A Leak In A Hot Tub

Not sure how to go about fixing the leak in your hot tub? Fear not, we’ve got you covered!

If It’s The Pump

The pump is a major part of the hot tub’s filtration system. It’s responsible for sucking in water from the tub, pushing it through the filter to be cleaned, and then sending it back into the tub via the return jets.

Hot tub pump leaks are quite common, and there are a few areas you should look at as leaks can come from multiple points.

The pump seal is where you’ll usually find a pump leak. Pump seals degrade due to improperly balanced water chemistry, or from normal wear and tear. Replacing this seal can be a bit tricky, as you need to dismantle the pump and replace two ceramic seals on the impellers using special tools.

Other places to check are the rinse line and union fittings. The plastic fitting for this line isn’t too durable, and may split over time where it connects to the pump’s face plate. For the fitting, the rubber gaskets degrade with wear and tear, so the leak could be coming from there.

In some cases where you have a leaky pump seal, there may be massive corrosion of the impeller shaft. At that point, it’s best to fully replace the pump.

How to fix it:

  1. Run the pump and see if you can spot where the water is leaking from.  
  2. Turn off the pump and place a finger underneath the rinse line fitting on the pump’s face plate. Check if your finger is wet or damp (replace the fitting if this is the case).
  3. The next spot to check is the union fittings to and from the pump. Feel around to see if there is any water leaking from them. If there is, unscrew them and replace their rubber gaskets which have probably become compromised.
  4. Check the pump seal. This may present itself as water dripping off the face plate, so you may be tricked into thinking it’s the rinse line fitting. You’ll have to remove the faceplate and examine the ceramic gaskets on both sides of the impeller.
  5. If the gaskets need replacing, do so. One side of the impeller plate may require a special tool as well as silicone to fit securely. If not installed properly, the leak will come back.
  6. Put the pump back together.
  7. Turn on the system and check for any leaks.

If It’s The Heater

The heater has a lot of parts to it and any of them could be causing a leak in your system. The heating element, thermostat, pressure switch, and sensors should all be checked to eliminate them one by one.

If you suspect the leak is coming from the heater, shutting down power to the tub should be done immediately. Anytime you’re dealing with water and electricity, you want to protect the system (and yourself) from electric shock.

Many times, if there are leaking parts inside the heater, they’ll need to be replaced.

But the most common leak with the heater will be at the pipe’s union fittings. This is due to degraded O-rings, gaskets, and will need to be replaced.

How to fix it:

  1. Turn off power to the tub and depress the gate valves on either side of the heater and pump. These valves cut off the flow of water through the pump and heater so you can work on them.
  2. Remove the union fittings where the leak is coming from (either from the pump to the heater, or the heater to the return line). Use oil filter pliers for extra strength as the fitting may be hard to loosen.
  3. Check the O-ring and gasket. One, or both of them, have probably degraded. This is an indication that other O-rings and gaskets may also need replacement.
  4. Remove the union fitting on the other end of the heater. 
  5. Replace all O-rings and gaskets at the same time so you won’t have to deal with another leak anytime soon.
  6. Reattach the union fittings and lift the gate valves.
  7. Turn the power on and run the tub. Ensure the leak is fixed.

If It’s The Lights

Leaks can come from inside the tub itself. 

Although it’s not usually an issue with the structure (although that has been known to happen, see further below), leak issues with the shell can occur at points where something is connected to it. This could be the lights or even the jets.

The cover on the light is called a lens or lens cover. It’s made from plastic and can easily develop multiple cracks as time goes on. While not every crack will leak, all it takes is one and you’ll need to replace it.

Fixing them isn’t too difficult, but you’ll need to access the light from behind the shell.

How to fix it:

  1. Drain the tub.
  2. Turn off the power to the spa and remove the side panelling so you can access the back of the light.
  3. Depending on your tub, you may have easy access to the light, or you may need to cut into the foam insulation. Use a utility knife and flathead screwdriver to remove the foam.
  4. Pull the light out of the socket.
  5. Unscrew the nut around the lens cover. You may need someone to hold the cover inside the tub as these may turn at the same time. Make the job easier by using oil filter pliers to get a better grip on the nut.
  6. Remove the lens cover from the tub and replace it with a new one.
  7. Add silicone around the lens cover behind the shell to help give it a watertight seal. Screw the nut back onto the lens cover.
  8. Put the light back into the socket.
  9. Add either another layer of silicone or insulating foam around the entire light.
  10.  Refill the tub and ensure the leak is fixed.

If It’s The Valves

Hot tubs come with different valves that help to block water flow.

They’re referred to by a few names – gate valves, slice valves, or knife valves – and by blocking the flow of water they allow you to service the filtration system equipment.

At times, these valves can fail and leak. This is because of their design. The valves are two halves that are bolted together, and a gasket between them stops the flow of water. When this gasket is compromised, you’ll see water leaking from the valve. 

How to fix it:

  1. Turn off the hot tub power.
  2. The valves have 4 bolts you’ll need to remove with a wrench in order to take the two halves apart. 
  3. Inspect the gasket. It’s most likely compromised in some way. 
  4. Replace the gasket with a new one.
  5. Put the two halves back together and tighten the bolts.
  6. Run the water and check to ensure the leak is gone.

If It’s The Hot Tub Shell

The shell is the tub itself, and leaks/cracks in it are rare. 

Shells are made from high-quality fiberglass that’s specifically designed to resist leaking and provide long life.

If you do have a crack in the shell, it’s usually because the tub isn’t level. When water weight isn’t evenly distributed, it can cause stress fractures in the shell. Getting it level (or at least within half an inch), will alleviate this problem, as more stress fractures can occur the longer it remains unbalanced.

If you do have a leak in the shell, it’s one of the easier types to identify. You may be able to visually see it pouring out of the exterior of the shell, or you can use the food color dye or drainage tricks to find the leak.

How to fix it:

  1. Turn off the power to the tub.
  2. Drain the spa using either a submersible pump or a hose attached to the drain plug at the base of the hot tub. 
  3. After identifying where the crack is, drill two small holes on either end of it.
    The drill bit should be slightly larger than the crack itself. This will prevent the crack from spreading further.
  4. Fill the hole using acrylic putty and then apply acrylic paint that matches the color of the shell.
  5. Sand and buff the crack until it’s nice and smooth.
  6. Depending on where the crack is, you may be able to pour water on it to test the patch job. If not, refill the hot tub and look to make sure the leak is gone.
  7. Test and balance the water, turn on the power, and enjoy the tub.

If It’s The Plumbing

Leaks in the plumbing can occur either underneath the shell of the tub, or in the equipment chain. 

It’s rare to have a crack in the equipment chain pipes, and you’re more likely to come across water leaking from underneath your tub. 

The pipes on the underside of the shell are made from flexible PVC. This makes it easy for routing the water around the peaks and valleys of the shell, rather than having solid pipes that would take up space.

However, because this tubing is more flexible, it can become compromised and begin to leak. This is usually due to temperature fluctuations, as exposure to extremely cold winters can wear it down and cracks can appear.

A leak in a hard PVC pipe is rare, but it may happen if the pipe develops a crack in it (again, usually due to extremely cold weather). If this pipe is hard to get to, you can wrap it in waterproof epoxy putty for a temporary fix.

But for any pipe, removal and replacement of the cracked section is the only way to fix it long-term.

How to fix it:

  1. If the leak is coming from underneath the tub, start by draining the water from it. 
  2. Prop the tub on its side and connect a hose to the water line. Run water through the line and you should be able to determine where the leak is.
  3. Turn off the water and power to the tub.
  4. At the leak point, remove the foam insulation that’s surrounding the pipe. Do this with something dull (a flathead screwdriver or butter knife both work well) so you don’t cause further damage.
  5. Cut out the portion of pipe where the leak is using pipe cutters. 
  6. You’ll need to purchase 2 PVC couplers (usually 1” wide), and a small piece of 1” flexible PVC pipe to replace the faulty section. Measure out the section so it fits perfectly.
  7. Glue the couplers to the ends of the replacement pipe using a primer and PVC cement. Give it about 2 hours to set. Then, glue the couplers to the pipe under the tub. Again, let it set.
  8. Turn the power back on and run the water to ensure the leak is fixed.
  9. Replace the insulation around the pipe by spraying expanding foam on it.

Leaks Can Be Draining

Having a hot tub leak is what you make of it. 

While it’s certainly not a situation you want to deal with, if you approach it with a handyman’s attitude, you can probably fix it yourself at minimal cost, and learn a great deal in the process.

Regardless, there are all kinds of reasons a tub can leak. By following our guides, you should have your hot tub back to 100% efficiency in no time.

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