5 Top Tips on Heating a Swimming Pool in Winter

Maintaining a heated pool in winter is the ultimate luxury, turning a seasonal hobby into year-round fitness and relaxation. At Discount Leisure Products, we know that the drop in temperature shouldn’t mean the end of your swimming season. Whether you have a permanent in-ground pool installation or a family pop-up, this guide covers everything you need to know about heating a swimming pool in winter, including our 5 top tips.

Imagine stepping out into the crisp winter air and diving into a steaming, crystal-clear pool. Pure bliss! For many UK pool owners, the “close-down” in October is a sad event, but it doesn’t have to be. 

Many of our customers ask us, “Can you heat a pool in the winter?” or “How does a pool heat pump work in winter?” The truth is, with advancements in technology, a heated outdoor pool in winter is more achievable and affordable than ever. This guide will walk you through the best methods for heating an above-ground pool in winter, in-ground setups, and pool heating tips for above and in-ground pools, ensuring you get the most out of your investment all year long.

What You’ll Need

To achieve a consistent heated pool temperature in winter, you will need:

• A Primary Heat Source: A heat pump.
• Solar Heating Boosters: Use a solar pod or solar mat to capture free solar energy and boost your primary heater.
• Heat Retention: A durable pool cover or solar cover to insulate the water surface and reduce heat loss overnight.
• Water Circulation: A pump and filter system capable of running in colder cycles.
• Winterisation Equipment: Items for when you eventually decide to winterise a pool heat pump. Learn more about this in our Ultimate Winter Pool Care Guide.

Our Top Tips: How to Heat a Pool in the Winter

Tip 1: Choose the Right Heater for Your Pool Type

Knowing how to heat a pool in winter depends largely on the pool’s volume and type.

For Above-Ground Pools: If you are heating an above-ground pool in winter, you have several options. The Intex 2Kw Above-Ground Swimming Pool Heater is perfect for smaller Easy Set or Frame pools. For a more eco-friendly boost, the Plastica Solar Pod or Relax Solar Pod PLUS can be daisy-chained together to capture natural UV rays and boost your pool heating with free solar energy.

For In-Ground & Large Pools: To maintain a heated in-ground pool in winter, you need power. The Thermotec 20kW Inverter Pro is designed for larger volumes and features Wi-Fi control, allowing you to monitor temperatures from the warmth of your home.

Tip 2: Supplement with Solar Heaters

While solar energy is less intense in winter, you can still use solar pool heaters to offset the costs of your heat pump.

Tip 3: Understand Heat Pump Limitations: How does a pool heat pump work in winter?

Standard heat pumps extract heat from the air and transfer it to your pool water. However, in very low temperatures, they can struggle.

For winter use, look for “All-Season” or “Inverter” models. The Thermotec Eco Inverter Heat Pump is designed to operate at lower ambient temperatures than standard “Summer” pumps, such as the SunSpring Swimming Pool Heat Pump.

Tip 4: Manage Heat Loss and the Cost to Heat Your Pool

The cost to heat an outdoor pool in winter can rise if you aren’t careful. Here are two ways to lower your costs.

• Insulate: Always use a solar cover when the pool is not in use. Without a cover, your heaters (both solar and electric) will be fighting a losing battle against evaporation.
• Inverter Tech: Use an inverter pump. Unlike standard pumps such as the Thermotec Eco Fun, which are either 100% “on” or “off,” inverters slow down once the target temperature is reached, saving significant electricity.

Notes on the cost to heat an outdoor pool in winter

The cost to heat an outdoor pool in winter is a primary concern for many owners, but with modern technology, it’s more manageable than you might think. Generally, heating a pool during the winter in the UK is about three to four times more expensive than in the summer due to the lower ambient air temperature, but the choice of heater makes the biggest difference.

Here is a breakdown of the estimated running costs based on typical UK energy rates (approx. 28p–30p per kWh):

1. Inverter Heat Pumps (The Most Cost-Effective)

Because units like the Thermotec Eco Inverter or Thermotec 20kW Inverter Pro extract heat from the air rather than creating it, they are incredibly efficient. Plus, they automatically adjust the fan and compressor speeds to match the pool’s heat demand precisely, reducing your running costs.

• Running Cost: Approx. £2.50 – £5.00 per day for an average-sized pool.
• Efficiency: For every £1 of electricity spent, you can get up to £5–£10 worth of heat (depending on the outside temperature). In winter, this efficiency (COP) drops slightly, but it remains the cheapest way to keep a heated pool warm.

2. Electric Heaters (Best for Small Pools)

Units like the Intex 2Kw Above Ground Heater are cheaper to buy upfront but more expensive to run over long periods.

• Running Cost: Approx. £10.00–£15.00 per day if run continuously to battle winter cold.
• Note: These are best used for smaller above-ground pools or as a rapid “top-up” alongside solar boosters.

3. Solar Pods & Mats (The “Free” Heat)

The solar pods and mats have £0.00 running costs.

• Winter Impact: While they won’t heat a pool to 28°C on their own in the winter months, they drastically reduce the workload of your primary heat pump. By pre-warming the water.

Tip 5: Set the Correct Temperature: What temperature should you heat the pool to in winter?

For active swimming, 25°C to 28°C is ideal for winter swimming. Anything higher will significantly increase your energy bills as the “delta” (the difference between the air and water temperatures) increases, making it uncomfortable to get out of the water.

FAQs:

Can you use a heated pool in the winter?

Absolutely. Swimming in a heated pool in winter is a fantastic way to improve your physical and mental well-being. The key is to have a warm robe nearby for when you get out!

Can you heat an above-ground pool in the winter?

Yes, but they lose heat faster than in-ground pools because the walls are exposed to the cold air! Using a combination of solar heating during the day and an electric heater or a small heat pump, like the Intex Above-Ground Swimming Pool heater, you can keep an above-ground pool at a swim-ready temperature for a winter swim session. However, you should ensure the pipework is insulated to prevent heat loss.

Are solar-heated pools warm in winter?

Generally, no. While our solar range is fantastic for extending the season in spring and autumn, solar alone usually cannot keep a pool at swimming temperature during the dark UK winter months. They are best used as “boosters” for a primary electric or inverter heater.

Troubleshooting & Maintenance

How to Winterise a Pool Heat Pump

If the temperature drops well below freezing and you aren’t using the pool, you must winterise your pool heat pump to prevent internal damage.

1. Disconnect Power: Ensure all electricity is isolated.
2. Drain Water: This is the most vital part of winterising a pool heat pump. Undo the unions and let all the water drain out of the heat exchanger to prevent ice from cracking the pipes.
3. Cover: Use a breathable winter cover to protect the chassis from snow and debris.

Swim all winter long with Discount Leisure Products.

Heating your pool during the colder months turns your garden into a year-round haven. By choosing the right tech, like a heat pump for efficiency or solar pods for a seasonal boost, you can enjoy a heated pool all winter long without breaking the bank.

Next Steps: Ready to upgrade your setup? Browse our full range of pool heaters to find the perfect fit for your pool size.

Your next read:

• 5 Steps to Ultimate Winter Pool Care
• How Do Swimming Pool Filters Work, And Which Is Best For You?
• Easy Ways to Heat Your Swimming Pool
• What Are The Advantages Of An Above-Ground Pool?