If you have a swimming pool and want to heat it so that you can enjoy warm water when you take a dip, then you need to be aware of the size heater you need. Often, people will purchase a heater only to later find out that it was no big enough and end up with cold water and a hefty bill to pay.

To help you, we will take you through the ins and outs of getting the right heater and explain the process you need to go through so that you can be confident that your heater will do exactly what you need it to.

Think About Seasonal Use

Pool boilers are designed for use mainly in the summer months because there is an expectation that the environmental temperature must be between 15 – 20 degrees for you to be in your pool. The good news is that this temperature range is often met from early April right through until October so you can expect a long swimming season. If you are keen to use your pool all year round, then you will need to factor this in when purchasing a boiler that has enough power to manage this effort.

As well as the seasonal considerations, you will need to be aware that there are so many other factors that will impact your pool, including:

  • The shape and construction of your pool
  • The wind speed around the pool.
  • The velocity of the pool water.
  • If you have kept your pool covered or left exposed to the elements.

Consider Your Usage

As with all big purchases, you need to consider how much use you are going to get from them. If you are not planning to use your pool regularly, then it may not be worth spending a lot of money on a pump that is designed for constant use. However, this does not mean you should get a smaller pump as it will not heat your pool when you want it too! Instead, look around to find the best boiler for occasional use and make sure that you invest in routine servicing so that the unit is kept in top condition.

If you are planning to make as much use of your pool as possible, then you would be wise to go for your maximum budget so that you can rely on it to perform consistently well. With constant use will come maintenance requirements and it is sensible to get a trusted boiler engineer to install it and maintain it for you so that you are never left with cold water when you want to have your daily swim.

Small or Large Pump

Each of the heating variables will have an impact on how quickly your pool warms up and how effective the heater is. For this reason, calculating the hourly loss of heat in kW is the best way to measure how powerful your heater should be. 

Many swimming pool manufacturers will recommend two different heaters for you to choose from and we would advise opting for the larger choice if your pool is large or located in an open space that is exposed to the elements. Ultimately, the larger your heater, the more powerful it is and the quicker it will heat the water for you.

Heater Sizes

Pool heaters come in a wide range of sizes so that you can get the right power for your pool. Take a moment to check our heater size guide to get a rough idea of what you will need.

Pool LengthPool WidthGallonsMinimum Size HeaterMaximum Size Heater
24 ft12 ft85009kW14kW
26 ft13 ft100009kW14 kW
28 ft14 ft117509kW29 kW
30 ft15 ft1350014 kW29 kW
32 ft16 ft1525029 kW29 kW

Let Us Help

If you are not sure what size heater you need, what brand you should choose or just want someone to double-check your choices then call Rowlen. Our team offer unparalleled expertise and have over 50 years of experience in the industry so that you can feel confident you are dealing with professionals.

We are more than happy to help you work out what you need, source it, install it and even maintain it for you. We also provide annual services so that you can get the most use out of your boiler as the years go by.

Do not buy the first pump you see, let us check it out for you so that you can look forward to long summer days spent lounging by your stunning pool.