Most Common Hot Tub Problems in Winter & How to Avoid Them

Winter is one of the best seasons to enjoy your hot tub – crisp air, warm water, and that cosy spa-day feeling at home. But it’s also the time of year when hot tubs experience the most breakdowns and callouts, especially across the UK’s colder regions.
Whether you’re trying to prevent expensive repairs or simply want your spa running smoothly all winter long, here are the most common hot tub problems in winter and how to avoid them.

1. Frozen Pipes & Equipment Damage

The Problem:

When temperatures drop below freezing, stagnant water inside pipework, pumps, or heaters can freeze, expand, and cause cracks or complete equipment failure.

How to Avoid It:

• Keep your water above 10°C at all times
• Maintain regular circulation cycles
• Ensure your lid is in good condition and fully insulated
• Book a Winter Service or Hot Tub MOT to check for vulnerable spots
• If leaving your hot tub unused, consider a professional drain down

2. Hot Tub Not Heating (Heater or Flow Issues)

The Problem:

One of the most frequent winter callouts is a hot tub that won’t heat. This is often due to:

• Scale build-up inside the heater
• Blocked filters
• Low water flow
• A failing circulation pump
• Tripped safety sensors

How to Avoid It:

• Clean or replace filters every 4–6 weeks
• Maintain correct water levels
• Use anti-scale treatments
• Book an early-year service to check heaters and sensors
• Don’t ignore low-flow or FLO error messages

3. Low Flow or FLO Error Codes

The Problem:

Cold water thickens slightly and can affect flow rate. In winter, dirty filters or weak pumps trigger flow errors more easily.

How to Avoid It:

• Always have spare filters ready
• Rinse filters weekly in winter
• Keep your water chemistry balanced
• Make sure your circulation pump is running smoothly
• Early signs of flow issues can often be spotted during a January service.

4. Tripped Breakers or Power Cut-Outs

The Problem:

Freezing weather puts extra strain on components like heaters and pumps. If they overheat, short-circuit, or draw too much power, the breaker will trip to protect the system.

How to Avoid It:

• Keep your heater and pumps clean and serviced
• Never run the spa with low water levels
• Check your electrical supply if the problem repeats
• Don’t continuously reset a breaker, call a professional

5. Cloudy or Smelly Water

The Problem:

Cold weather can mean more frequent lid use (less natural aeration), bather load from holiday guests and slower chemical reaction times, all of which in turn can lead to cloudy or smelly water. 

How to Avoid It:

• Shock dose weekly in winter
• Use a quality winteriser chemical
• Rinse filters more often
• Ensure correct sanitiser levels (bromine works especially well in colder water)

6. Frozen Covers or Waterlogged Lids

The Problem:

Hot tub covers become heavy and waterlogged, reducing insulation and pushing up running costs. In some cases, the top layer can freeze, making it harder to open and risking damage to the hinge.

How to Avoid It:

• Check for cracks or splits in the vinyl
• Clean and protect your cover with a UV-safe conditioner
• Replace severely waterlogged lids
• Consider an insulated heat-retention cover upgrade

7. Leak-Related Heat Loss

The Problem:

Small leaks quickly become big problems in winter because the hot tub has to work overtime to maintain temperature, increasing the risk of freezing and component strain.

How to Avoid It:

• Listen for unusual pump cycling
• Look for wet areas around the hot tub base
• Monitor water levels
• Book a repair or service if you spot anything unusual

Avoid Winter Breakdowns – Book a January Service

January is one of the best times to get ahead of winter hot tub issues. A professional service helps identify:

• Early signs of freezing risk
• Weak pumps
• Blocked or damaged heaters
• Flow problems
• Leaks that worsen in cold weather

It’s much cheaper to prevent winter damage than repair it.

Our engineers cover Hampshire, Essex, Surrey, Sussex, London, Hertfordshire, and more.

Stay warm, stay safe, and keep your spa winter-ready.