Hot Tub Keeps Deflating or Losing Air? Here's How to Fix It

You pumped the tub up rock-solid, and a day later the walls are soft and saggy — or it won't hold its shape at all. It's one of the most common faults we hear about across Bournemouth, Poole and Christchurch, and it spikes every summer when tubs are inflated, used hard and left out in fluctuating temperatures. The reassuring news: the majority of "keeps deflating" problems are a loose valve or a small, findable puncture — both of which you can usually sort yourself for the price of a £10 repair kit, long before you'd ever need a new tub.

This guide covers all the inflatable brands — Lay-Z-Spa, Intex PureSpa, MSPA and CleverSpa. We start with the 60-second checks (including the one that fools nearly everyone) and work through to the soapy-water leak test the manufacturers themselves recommend.

💡 First: is it actually a leak? Air contracts as it cools. A tub pumped firm in the warm afternoon sun will naturally go softer overnight as the temperature drops — Bestway's own manual notes the spa "will require additional air to be added from time to time" due to day-to-night temperature changes. Top it up in the morning. If it then holds firm through the day, you have no leak at all — just physics.

Quick Checks First (60 Seconds)

1. Has the Temperature Just Dropped?

As above — this is the number-one false alarm. If the tub only goes soft overnight or after a cold snap and firms back up once you top it off, nothing is wrong. Air that filled the walls when warm simply takes up less space when cool. Avoid over-inflating in the heat of the day, as the reverse (expansion in hot sun) puts the seams under strain.

2. Is the Inflation Valve Fully Seated and Tight?

A loose air valve is the single most common real cause of a deflating inflatable tub. Make sure the valve is fully inserted and screwed firmly into the inflation hole. Many tubs come with a small wrench: hold the back of the valve from inside the wall with one hand and turn the wrench clockwise to tighten. Two rules — don't over-tighten, and never adjust the valve while the spa is in use.

3. Listen Before You Look

With the tub fully inflated and the area quiet, put your ear close to the valve, the seams and the pump connection ports. A slow leak over 24+ hours is often too small to see but just audible up close — and a quick way to narrow down where to spray.

The Definitive Test: Soapy Water

This is the method Lay-Z-Spa, Bestway and professional repairers all use, and it's the most reliable way to pinpoint an escaping-air leak:

Mix diluted washing-up liquid in a spray bottle (a good squirt in warm water).
With the tub fully inflated, spray it methodically over the surface — start at the inflation valve, then work around the seams, the top ring, the pump connection ports and the base.
Watch closely: bubbles will form and grow wherever air is escaping.
Mark the spot, deflate, clean and dry it ready for a patch.

If the bubbles are at the valve, you don't need a patch — just tighten it as above. If they're on the liner or a seam, you've found your puncture.

🖐️ No spray bottle? Use the wet-hands trick Wet the backs of your hands and forearms and move them slowly over the inflated surface. The cooling sensation of escaping air is surprisingly easy to feel, even on very small leaks. It's a good first pass before you reach for the soapy water.

Where Leaks Usually Hide

From years of inflatable-tub repairs, certain spots account for most punctures and slow leaks. Check these first:

The inflation/deflation valve — loose or worn, the most common culprit of all.
Around the pump (heater) connection ports — a high-stress area that flexes every time the pump is attached.
Seams and joins — folding for storage and years of inflation cycles can open a tiny split.
Underneath — a trapped stone or grit is a classic cause, especially without a ground mat.
Where the tub rubs brick, decking or fencing — abrasion wears a hole over a season.
The top inflated ring — pet claws and sharp jewellery leave fine punctures here.

How to Patch a Confirmed Puncture

Once the soapy water has shown you the leak, a puncture in the liner body is a genuine DIY fix with an inflatable hot tub repair kit (transparent vinyl patch + vinyl glue, around £10):

Clean and degrease the area thoroughly — vinyl glue won't bond to anything oily or dirty. Dry completely with a paper towel; no moisture must remain.
Cut the patch so it covers the puncture generously, with margin all round.
Apply the glue, press the patch down firmly to push out any air bubbles, and leave it to cure for a couple of hours (longer is better).
Re-inflate and re-test with soapy water over the patch. If bubbles still appear, the patch was too small or the glue didn't set — repeat. If a new area bubbles, you have a second puncture; inspect the whole tub again.

A £10 kit and an afternoon beats £400–£500 for a replacement tub every time. Silicone sealant works only as a rough temporary stopgap — it's not a lasting fix.

⚠️ When NOT to keep patching Repeated patches on the same liner, a leak hidden inside a seam, or multiple punctures usually mean the liner is near the end of its life. At that point a replacement liner (or a warranty claim if the tub is new) is the sensible call rather than chasing leak after leak.

If You Still Can't Find the Leak

Some leaks defeat the soapy-water test — they sit underneath the tub, deep inside a seam, or there are several tiny ones at once. If your spa deflates within 12–24 hours and you've checked the valve and visible surfaces without success, it's worth bringing in a local engineer or liner-repair service. They can pressure-test the liner properly, locate hidden leaks and either seal them or fit a new liner — far cheaper than writing off the tub.

Can't Find the Leak? Get Expert Help

If the tub keeps going soft and the leak is hidden in a seam or underneath, a local engineer can pressure-test and repair it. We'll match you with someone who knows your brand.

📞 Get a Free Quote

How Much Does a Deflation / Leak Repair Cost?

Typical costs in the Bournemouth area for air-loss and puncture faults:

Tightening a loose valve: £0 (DIY, supplied wrench)
Vinyl puncture repair kit (DIY patch): ~£10
Professional puncture location & repair: £40–90 depending on number of leaks
Replacement liner (multiple/seam failures): £60–150 depending on model
Typical engineer call-out: £40–80 (often includes the first 30 mins of labour)

The vast majority of deflation problems cost under £20 to fix yourself — well below the £400+ of a replacement tub.

Prevent It Happening Again

Always use a ground mat under the tub — it stops the most common cause, stones underneath.
Keep the tub clear of sharp decking edges and brick walls it could rub against.
Don't over-inflate, especially in hot weather — firm, not drum-tight.
Check the valve is snug before each use.