How To Heat A Pool

Knowing how to heat a pool properly means choosing the right system for your climate, pool size and how often you swim. In Perth we install gas heaters, electric heat pumps and solar pool heating systems across suburbs from Joondalup to Rockingham, and the best solution is never the same twice. What works for a compact plunge pool in a shaded courtyard will not suit a 60,000 litre family pool in direct sunlight all day. This guide covers every pool heating option, what each costs to run and the factors that determine which system will heat your pool efficiently. For pricing, installation and servicing, see our pool heating page.

Why Heating Your Pool Matters

An unheated swimming pool in Perth drops below a comfortable swimming temperature by late April. From May through August the water sits around 15 to 18 degrees, which is cold enough that most families stop using it entirely. That is five months of dead investment. Heating pools extends your swimming season from the usual five months to nine or even year round depending on the system. Beyond extra swim time, the benefits of warmer water include support for exercise routines, muscle recovery and making the pool usable for older family members and young children who feel the cold faster. The cost of heating is almost always less than the cost of leaving a pool unused. More pool use for more of the year is the whole point.

Types Of Pool Heating Systems

Three main types of swimming pool heaters cover the residential market in Australia. Each has a different upfront cost, running cost and set of trade offs that suit different individual circumstances.

Gas Pool Heaters Quick But Costly

Gas pool heaters burn natural gas or LPG to generate heat through a combustion chamber and heat exchanger. They raise water temperature fast. A properly sized gas unit can heat a 50,000 litre pool by 10 degrees in under 12 hours, which makes gas heaters the pick for pool owners who heat on demand rather than running the system constantly. Hot gas combustion delivers results regardless of weather conditions or outside air temperature, so they work on rainy days, overnight and through the winter months when solar output drops to nothing. The downside is cost. Gas prices in WA have risen steadily and running a gas pool heater daily through cooler months can add $800 to $1,500 per year depending on pool heater size and desired temperature. Gas heaters also have a shorter lifespan of five to ten years compared to other swimming pool heaters. We fitted a Rheem gas unit for a client in Joondalup who only uses his pool on weekends. For that pattern, gas makes sense because the running hours stay low and the pool reaches the ideal temperature within a few hours of firing up.

Electric Heat Pumps Efficient And Reliable

Electric heat pumps do not generate heat directly. They extract warm air from outside air and compress it through a refrigerant cycle to transfer energy into the pool water via a heat exchanger. Pool heat pumps deliver three to six units of heat for every unit of electricity consumed, which makes them the most energy efficient pool heating option for year round use. In Perth where air temperature rarely drops below 8 degrees even in July, a heat pump operates effectively for the entire year. Inverter models from brands like Madimack and AstralPool adjust their output to match the heating requirements rather than cycling on and off, which saves electricity and extends the unit’s long lifespan of 10 to 20 years. Electric heat pumps take longer to raise the temperature compared to gas, typically one to two degrees per day, so they work best when left running to maintain a consistent water temperature rather than heating a cold pool quickly. For families who swim regularly, a heat pump is usually the most cost effective choice over time.

Solar Pool Heating Sustainable And Low Cost

Solar pool heaters use roof mounted collectors to absorb sunlight and transfer that heat into the pool water as it circulates through the panels. Perth receives around 3,200 hours of sunlight per year, giving solar pool heating a genuine advantage over southern states. A well sized solar heating system can extend the swimming season by four to six months and the running cost is close to zero because the sun does the work. The pool pump circulates water through the collectors, so the only electricity cost is the pump itself. Solar pool heating works best on north facing roofs with minimal shading during the warmest part of the day. The limitation is obvious. On overcast days, rainy days and at night, solar output drops and the pool loses heat. Pairing solar with a heat pump creates a hybrid system that covers every weather scenario and keeps the water at a stable temperature year round while remaining environmentally friendly.

Using Pool Covers To Retain Heat

Pool covers are the simplest upgrade that delivers the biggest return on any heating system. A solar pool cover reduces heat loss through evaporation by up to 70 percent and can raise water temperature by several degrees on a sunny day without powered heating. Evaporation is the primary cause of heat loss on outdoor pools, especially in Perth where the Fremantle Doctor blows across the pool surface area every afternoon through summer. Without a cover, you are heating the pool during the day and losing most of that energy at night. We recommend a 500 micron solar blanket as the minimum. Thicker covers retain more heat and last longer. Pool covers also keep debris out, reduce chemical consumption and cut water top up costs. For anyone serious about heating pools efficiently, a cover is not optional. It is the foundation that every other system builds on.

Factors To Consider When Choosing A Pool Heating System

The right system depends on pool size, how often you use it, your budget for installation and running costs, available roof space for solar, and whether your property has gas. Wind exposure matters more than most people realise. A pool in a sheltered courtyard retains heat far better than one exposed to afternoon sea breezes. Pool area and surface area affect how quickly the water cools. Deeper pools hold heat longer but take more energy to warm up initially. Your desired temperature also plays a role. Keeping a pool at 28 degrees costs noticeably less than maintaining 32 degrees, especially through the cooler months. If you are unsure, we can assess your pool and recommend the best solution for your situation based on what we see working across hundreds of Perth pools each year.

How To Maximise Pool Heating Efficiency

Getting the most from your system comes down to habits as much as hardware. Use a solar pool cover every night and whenever the pool is not in use. Run the pool pump during the warmest part of the day to maximise solar gain if you have solar collectors. Schedule electric heat pump operation during off peak electricity periods to reduce cost. Keep filters clean because restricted flow forces the heater to work harder. Maintain proper water chemistry to protect the heat exchanger and extend the system’s life. Trim trees or structures that shade the pool area during peak sun hours. These steps cost nothing but reduce energy consumption noticeably. Proper maintenance of the heating system itself, including annual servicing, prevents breakdowns and keeps energy efficiency at its peak.

FAQs About Pool Heating

What Is The Best Way To Heat A Pool In A Cold Climate

Gas pool heaters or electric heat pumps designed for low ambient temperatures work best. In Perth our winters are mild enough that a heat pump handles the job comfortably, but a gas heater provides faster results if you only swim occasionally.

How Can You Heat A Pool Without Increasing Energy Bills

Solar pool heating paired with a solar pool cover is the lowest cost option. A heat pump on off peak electricity is the next best. Both operate compared to gas at a fraction of the running cost over a full season.

Is Solar Pool Heating Enough In Winter

In Perth, solar alone keeps the pool swimmable into May and from September onward. Through June to August, a backup heat pump or gas heater supplements the solar heating system on cooler and overcast days.

How Long Does It Take To Heat A Pool

Gas heaters warm a pool faster than any other system, raising the temperature several degrees in a few hours. Heat pumps take one to two days to bring a cold pool up to the ideal temperature. Solar depends entirely on sunlight and weather conditions.

Do Pool Covers Really Help

Yes. A pool cover reduces heat loss by up to 70 percent overnight and can warm the pool by several degrees during the day. It is the single most cost effective addition to any heated water setup.

Conclusion

There is no single answer to how to heat a pool because every pool and budget is different. Gas heaters deliver speed. Heat pumps deliver energy efficiency over the long term. Solar pool heaters deliver sustainability with almost no running cost. In most cases the best solution combines two of these with a quality pool cover. For advice on which pool heating system suits your pool, or to book installation and servicing, get in touch with our team. We install and service every type of pool heater across Perth and can have your swimming pool pool warm and ready for the season ahead.