Help! I’ve a leak! How to Detect and Fix a Hot Tub Leak


It’s not a good feeling to know that your Hot Tub is leaking. At first, you might be tempted to panic at the thought of costly repairs and a lot of problems, technicians, costs, more costs. Stop! Take a deep breath and relax! A lot of Hot Tub leaks are easy to detect and cheap to repair.

Here’s a list of the most common causes of Hot Tub leaks.


Pump Leaking

At some point it happens to all Hot Tub owners. In fact, It is one of the most common areas that may be overlooked. In other words, if a Hot Tub pump leaks, it is the shaft seal, the unions (the parts that you twist by hand to attach the pump to the pipe or the wet end.

With a Hot Tub pump leak, search carefully with a flashlight to determine the exact cause of the leak. If it is the unions, make sure they are tight enough. If you can’t get them any tighter, undo them and look for the black rubber O gasket. If that is not present or has perished, replace it, tighten up the unions and you should be on your way.

The wet end seal is the same. Make sure all the screws that hold it in place are tight enough. If they are, then undo and look for the rubber seal. Again, check to see if it has perished and replace if necessary.

Pump leaks are quite easy to fix.

Light Leaking

It may sound odd to have a light that leaks, but its not really the light but more the recess where it sits. Certainly in some of the older tubs that don’t have LED lighting, the lens of the Hot Tub lamp, especially with high temperature halogen lamps, can become loose or cracked.

Usually the lamp housing or recess is cracked. This can easily be fixed with some cheap epoxy putty from the hardware store or even Amazon. If you get the plumbers one, it can even set under water so you may not even need to drain your tub.


Filter Leaking

This is probably the easiest part to detect a leak. There are really three places that a filter can leak. The unions that attach it to the pipe. Like with the pump unions, check they are tight and check for the rubber gasket that is inside.

The next place is the bleed screw. Check that it is tight and of course there is no water coming out. This too has a rubber gasket on so you may need to replace that too.

The last place on the filter is the housing itself. If it is the cartridge style, there is a cylindrical screw that attaches the body to the base. This has a rubber gasket inside and this can become worn as you change your filters regularly. Replace and you should be all set.

Plumbing Leaks the Pipes and Joints

You have to remember that the Hot Tub plumbing is a pressurized system so over time, the joints and seals are put to the test as we fire hot water through them during use. This should be a visual test and you should be able to chase the water back to the leaking joint.

A point to note here is that gravity and “the easiest route” means that it may appear to be coming from one location when it is in fact another – this has happened to me on several occasions.

When fixing plumbing leaks, if you are draining the tub and drying things out, then you can use adhesive. If you are looking to do a patch fix, I recommend epoxy under water putty, its great stuff and easy to use. Sets under water too so no draining and downtime of your tub!


A Well Made Joint Doesn’t Leak

What do I mean by this? Well, if you’ve been reading my site you know that it is all about building your own tub. One of the mistakes that I made was that I tired to reduce the number of joints I had by bending pipe. My thought process was less joins, less chances of leaks.

The problem that I have is that in doing this, I was making joints that were not “well made”. I was having to force the pipe in at strange angles. Confession time for me. In pretty much all the joints that I had to force and that have not been square into the connectors, they have leaked at some point!

Therefore, my top tip of the day here is that if you are doing your own plumbing, then make sure you do nice, square, well made joints and they will not leak. The pipe fixings for concrete tubs are so well made and are great to work with.

Pipe cement them in and they just don’t leak!

Last confession for the day, make sure you actually glue the joint! I managed to put together a secion of the plumbing in the control room of my own tub and I forgot to cement in one of the 90 degree 2” water pipe joints.

One Sunday afternoon, I remember it well as I was watching the F1, the blower speed increased dramatically, then everything went dead. By the time I had realized the electricity had cut out, the control room was under water and the tub had emptied by a third.

Expensive mistake when you have to replace the pump as you filled it with water – all because of a dry joint!

Food for thought.

Can I Help You?

If I can help you in any way I would love to hear from you. You can get in touch using the form below.

Thanks - Andi


Hi, Andi here. I own and also write all of the articles and info pages on the site. Some years back now, I built my own hot tub but struggled to find the information I needed. So, once my tub was complete, I started this website to help others in their own pursuit of hot tub and plunge pools DIY building information.

Today, I've helped over 1000 DIY customers just like you all over the world build hot tubs and pools. Have a good look around the site, there are lots of resources here. Please do get in touch if I can help you. - Cheers, Andi

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