The short answer
Running cost depends mostly on how you heat the pool and whether it is indoor or outdoor. For an outdoor pool, heating is the big item: an air-source heat pump can be roughly £200–£500 per season, while gas heating is far higher at around £800–£3,000 per season. On top of heating you have the circulation pump, chemicals and routine maintenance, which together add a few hundred pounds a year. An indoor pool costs more to run — commonly around £500–£600 per month — because you heat both the water and the room and run ventilation and dehumidification year-round. These figures assume a 2026 electricity price of roughly 27.7p per kWh; your tariff and how warm and how often you swim move the number.
Running cost is really four things added together: heating, the pump, chemicals and maintenance. Heating dominates, so the choice of heat source — and indoor versus outdoor — makes the biggest difference. The figures below assume a 2026 electricity price of about 27.7p per kWh.
Typical yearly running cost
- Heat pump (outdoor)~£200–£500 / season
- Gas heating (outdoor)~£800–£3,000 / season
- Indoor pool (all-in)~£500–£600 / month
- Pump, chemicals, upkeepa few hundred £ / year
- Electricity assumed~27.7p / kWh (2026)
What makes up the running cost
- Heating: the largest cost. A heat pump works out lower in cost than gas or direct electric for most outdoor pools, because it moves heat rather than generating it.
- Circulation pump: runs daily to filter and circulate the water; a variable-speed pump uses less.
- Chemicals: chlorine or salt, plus pH balancers, across the season.
- Maintenance: cleaning, servicing and the occasional repair.
- Covers: a good pool cover cuts evaporation and heat loss, which is the simplest way to lower running cost.
| Item | Typical figure | Notes |
|---|---|---|
| Heat pump (outdoor season) | ~£200–£500 | lower running cost than gas |
| Gas heating (outdoor season) | ~£800–£3,000 | depends on gas price & use |
| Indoor pool (all-in) | ~£500–£600 / month | water + room + dehumidification |
| Pump, chemicals, upkeep | a few hundred £ / year | varies with pool size |
Indicative UK figures for guidance, assuming ~27.7p/kWh electricity (2026). Sources: Compass Pools and Hayward running-cost guides.
How to keep running cost lower
The pool that costs least to run is one that loses little heat. A well-fitted pool cover is the single biggest saver — it cuts evaporation, which is where most heat goes. Beyond that, an air-source heat pump typically works out lower in cost than gas or direct electric heating; running the pump at a lower speed for longer uses less than a single-speed pump at full power; and heating to a sensible temperature rather than bath-warm makes a real difference. For outdoor pools, only heating during the swimming season (rather than year-round) keeps the seasonal figure down.
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Frequently asked questions
How much does it cost to run a swimming pool per year in the UK?
For an outdoor pool, heating is the main cost — roughly £200–£500 per season with a heat pump, or £800–£3,000 with gas — plus a few hundred pounds a year for the pump, chemicals and upkeep. An indoor pool is higher, commonly around £500–£600 per month.
Why do indoor pools cost more to run?
Because you heat both the water and the room and run ventilation and dehumidification all year. That typically pushes an indoor pool to around £500–£600 per month, well above a seasonal outdoor pool.
What is the simplest way to lower running cost?
A well-fitted pool cover. It cuts evaporation, which is where most heat is lost, so the heater works less. Pairing it with a heat pump and a variable-speed pump lowers the cost further.
Sources & further reading
Figures on this page are typical UK ranges drawn from published sources and depend on your specific property. They are guidance, not a quotation.