Swimming pool heater problems

Your pool heater is both the most expensive and the most complex item of swimming pool equipment that you have and for this reason it is important to spot any water heating problems as soon as possible.

With gas fired heaters, all but the simplest of heater problems will require a heating engineer, however many “perceived” problems can be resolved (or identified) simply and quickly without the need to call out an engineer.

Here are some common pool heater issues with suggestions for troubleshooting a solution or diagnosing a problem for your pool maintenance man or heating engineer. At the very least this might save you some “diagnostic charges” and it may remove the need for a call-out altogether.

Issue – The pilot will not light, or the heater fails to ignite.

For the pilot light ensure that –

• The gas is turned on (or the tank has propane in it)
• The gas pressure is adequate (and not too low)
• The pilot feed tubing is not blocked or cracked
• There is an adequate air supply

If the heater does not ignite determine if –

• The heater is switched on
• The pilot is lit
• The gas supply valve is open
• The thermostat is not set below the current water temperature
• The pump is running
• The valves are open

Issue - The water temperature is too low

Find out if –

• The heater is switched on
• The thermostat is set below the temperature that you desire
• The heater is cutting off, or a cut-out switch is being activated
• The heater is adequate for the pool size or climatic conditions
• There is a blocked filter or closed valve
• The thermostat is working

Issue – The heater is producing smoke, has heat damage or is leaking water

These issues will almost certainly require an engineer, but you can do some basic diagnosis by checking that –

• The gas pressure is not too low
• The air supply is adequate
• There is no evidence of down drafting
• The pump is not too powerful for the heater (leak)
• The internal bypass is working correctly (leak)
• There are no loose connections, gasket leaks etc (leak)
• There is no evidence of sooting with the heat exchanger (leak)

For all other problems run through the basic checklist of ensuring that settings are correct, valves are open, the gas supply is adequate and that pressures are within guidelines. Check for blockages, interruptions in gas or air supply and adequate venting.

Many problems, particularly those at the beginning of the season, may not be problems at all, but simply the result of changing a setting or flicking a switch at the end of the previous season. Always make these simple checks yourself before you enlist the help and charges of an engineer.