A leaking hot tub looks like a disaster and usually isn't. The overwhelming majority of leaks we're called out for come down to a worn o-ring or gasket. The hard part was never the repair. It's finding where the water is actually coming from.
As always: shut the breaker off before you open any panel.
The mistake almost everyone makes
Water runs downhill. When you open the cabinet and find a wet spot, your instinct is to fix what's wet — but that puddle may have traveled a foot or more from the actual source. The wettest place is almost never the leak. That's why people replace a fitting, refill the tub, and find themselves right back where they started.
Three ways to actually locate it
The toilet paper trick. Nothing absorbs water faster. Take two sheets, fold them in half, and wrap them around a suspect line or fitting without touching it first. Pull it off and read where it's wet. Because gravity is doing the work, wet toilet paper at the top of the wrap tells you the source is above it, and you keep working upward until you find it. We've traced leaks three fittings away from where the puddle was sitting.
Drop the water level. If you suspect a specific component — a light, a jet, a fitting — lower the water to just below it. If the drip stops, you've confirmed it. If it keeps going, the leak is lower than you thought. Simple, and it costs nothing but time.
The bubble test, for small leaks. Close all the air controls, then run each pump on its own. Watch the jets for air bubbles. A running pump pulls a vacuum on the plumbing, so a crack or a pinhole on the suction side draws air in instead of pushing water out. Bubbles at a particular jet point you to that section of line.
Where leaks actually come from
O-rings and gaskets are the number one cause, and heater gaskets top that list — they take more heat and more chemical exposure than any other seal in the tub.
Here's what happens to them: an o-ring that's done its time stops being round. It compresses into a squared-off profile and no longer seals, even though it looks fine sitting in your hand. That's why any time a pump or union comes apart in our shop, the o-rings get replaced on the way back together — not inspected and reused.
Pump unions and shaft seals are common too. So are slice valve o-rings, which hard water and neglected chemistry chew through quickly.
Cracked plumbing is the other big one, and it's usually freeze damage from a tub left unattended through winter. Rodents getting into the cabinet and chewing vinyl tubing happens more often than you'd think.
It could also be a jet, a slice valve, a broken diverter valve…
One thing not to do
Don't try to cure a leak by cranking the fitting tighter. Past a certain point you warp the fitting, and you still won't close the gap — now you've got a leak and a damaged part. A quarter turn is worth trying. Leaning on it with channel locks is not.
Where DIY stops
Hunting the leak with toilet paper and a flashlight is genuinely something you can do yourself, and narrowing it down before you call anyone saves time either way.
The repair is a different question. Many leaks sit behind sprayed-in foam insulation that has to be dug out to reach the fitting, and replacing a pump seal or a heater gasket means draining the tub and opening up plumbing. If the leak is under the shell, inside the foam, or anywhere near the pump or heater, that's the point to call us.
Or forget everything you just read and let us handle it all.