Wondering how to find the source of a hot tub leaking? Our comprehensive guide helps you detect leaks early, saving time and preventing costly repairs.
Stay Safe First: Power Off and Check the Basics
Before you look for a leak, make the hot tub safe. Switch off the power at the isolator or main switch, not just the control panel. If you can, unplug it too. Do not remove panels while it is still live. Let the pumps and heater cool down.
Next, check the simple things. Make sure the drain cap is tight and any fill hose is fully shut. Check the filter lid is seated and the rubber seal is not twisted. Look for a valve left half open after topping up. Wipe away old puddles so new water is easy to spot. Keep children and pets away while you work. Wear shoes with good grip and use a torch in daylight.
Confirm it is a leak and not normal water loss
Hot tubs can lose water even when nothing is wrong. Warm water evaporates, and this is faster on dry days. Bubbles and the air blower can speed it up. First, mark the waterline with a piece of tape on the shell. Check the level after 12 hours and again after 24 hours, with the cover on and the pumps off.
If the drop is tiny, it may be normal. If you used the tub, splashing and wet swimsuits can take out more water than you expect. Also think about topping up. A hose left running for a short time, then turned off, can hide earlier water loss.
Next, try a bucket test. Fill a bucket with hot tub water and place it on a step inside the tub, so the bucket water level matches the tub water level. Mark both levels. Put the cover on and leave the tub unused for 24 hours.
After that, compare the marks. If the tub level drops more than the bucket, you likely have a leak. If both drop the same, it is mainly evaporation. Then check when the loss happens. Does it drop faster after heating, after the jets run, or after using bubbles? Look for drips at the filter area while the pump runs.
Check the drain cap, any hose fitting, and any tap for slow weeps. Finally, inspect the ground where the tub sits. A damp patch that keeps growing, even when the tub is not used, is a strong clue.
How fast is the water dropping? What it can tell you
How quickly the water level falls can point to the cause. A fast drop, a few centimetres in a few hours, can mean a loose fitting, a split pipe, or a cracked part. A slow drop, about a centimetre a day, can mean a drip from a joint, seal, or valve. Watch what happens with the pumps off. If it still drops at a steady rate, the leak may be in the shell, the drain, or a pipe below the waterline.
If it only drops when the jets run, check parts under pressure, like pump unions and heater connections. Stop filling once the water reaches a stable level. That level can match the height of the leak inside the cabinet.
Look for wet patches around the base and cabinet
Once you know it is leaking, start with what you can see from the outside. With the power off, walk around the hot tub and check the base. Use a torch to look under the cabinet edge, especially on the side where the pumps and heater sit.
Feel the ground for soft, wet areas and look for water tracking along paving joints. If the tub sits on grass, check for a darker patch that stays damp. Remember that water can travel, so the wet patch may show up a short distance away from the source. Next, check each corner and the bottom lip of the cabinet.
Look for stains, swelling, or mould, as these can show a slow leak over time. If your tub has removable panels, take one off at a time and look at the inside base. Use kitchen roll or a dry cloth and press it against the timber frame and floor. Even a small drip will leave a clear wet mark. Pay close attention to the equipment bay. Check around pump unions, heater fittings, and any drain taps.
If you see a wet trail, follow it upwards to find the highest wet point, as this is usually closer to the leak. If the base looks dry, run the jets for a short time, then switch them off and look again. Take photos as you go so you can compare changes after an hour or two. If you find water near electrics, stop and get help immediately.
Look for leaks in hidden pipework inside the cabinet
If you cannot see the source outside, look inside the cabinet. Remove the equipment panel if it can come off. Use a torch to spot damp foam, wet pipes, or drops on fittings. Dry the area with a cloth, then watch for fresh moisture. Turn the pump on for a short time, then turn it off and listen for dripping.
Check each joint where a pipe meets a jet body, valve, pump, or heater. Feel around unions for a fine spray. If a hand fitting feels loose, tighten it gently, but do not force it. If you spot a split pipe or cracked part, stop using the tub and plan a repair. A small leak can become a bigger one.
Our certified technicians diagnose, service and replace every major component such as pumps, jets, controls, pipework and more. We use genuine parts, transparent pricing and guaranteed workmanship to restore efficiency, safety and relaxing comfort. Call today for hot tub repair in Guildford, Woking and Horsham.
