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Product Listing

Oil and Gas Swimming Pool Heaters

The most common type of heater and probably one of the most economical is the Gas Heater (those that use natural or propane gas as the heating fuel). Gas Pool Heaters (otherwise known as Gas Boilers) are a great way to heat your pool all year round and are available for indoor and outdoor pools.


These type of heaters must be installed by a registered gas engineer in accordance with the appropriate regulations. These include the size and position of the flue, the gas supply and ventilation. Some gas heaters are designed to stand outside a building in the open air and in this case there is no flue but the heaters positioning is important and again must in accordance with regulations.


In general there are three separate switches which control the heater. Firstly is the on/off switch on the heater itself. Secondly is the thermostat, which will allow you to set your desired temperature of the water and finally a gas cock on the gas supply. This is a small valve which will allow you to open or shut off the gas supply to your heater. The heater also has three built in safety devices to protect yourself and the equipment from various elements. Firstly is a high limit thermostat, which will shut down the heater if it gets too hot and consequently switch the heater back on when it has cooled down. A safety gas valve, which will cut off the gas supply if the flame or pilot light goes out and a pressure switch which will turn the heater off if the pool water stops flowing and back on once flow has resumed.



The thermostat on gas boilers is deliberately not very accurate as the pool water passing through it varies considerably in temperature. The difference in temperature between the water drawn from the main drain and that from the skimmers can be as much as 10 degrees F. The easiest way to get your desired temperature is to turn on the filter pump to run constantly, along with the heater and turn the thermostat up to maximum. Put your swimming pool thermometer into the pool water and when that reaches your desired temperature return to the plant room, turn the heater thermostat down to the position where the heater just goes out; the thermostat setting will then match the pool water temperature and will then maintain that temperature in the pool.


When sizing a gas boiler, the goal is to have a heater that has enough capacity to heat the pool to your desired level in a reasonable amount of time. Maintaining that temperature is a lot easier once the pool is up to temperature. Firstly, the capacity of most pool heaters is rated in BTU's or British Thermal Units. One BTU is the amount of heat required to raise the temperature of one pound of water, one degree F. And since there are 8.33 pounds per gallon it takes 8.33 BTU's to raise one gallon of water, one degree F.


MasterTemp from Pentair £2,350.00
The Certikin Genie Condensing Boiler £2,500.00
The Certikin Oil Heater £2,900.00