POOL HEATER TROUBLESHOOTING GUIDE

Heater won’t turn or stay on? When your swimming pool heater malfunctions, troubleshooting the source of the problem can be more complex than working with filters or pumps. You have to determine where the problem is occurring within the heating system before you can determine how to repair it. This does not always require a call to a technician, but it is wise to consult your heater manufacturer’s service manual before you begin troubleshooting so that you are familiar with the location of each part and how it functions.

A dirty swimming pool filter can result in low pressure, and if the pressure leaving the filter is low, this will cause the pressure switch to turn the heater off. Check the shut-off valve on gas heaters to ensure that the valve is open and thus supplying fuel to the heater. If the unit is electric, make sure electrical connections are tight and that there is no corrosion at the terminals. If this doesn’t resolve the problem, check the transformer by attaching one voltmeter lead to a terminal on the transformer. Touch the other terminal with the other lead. A reading of between 20 and 28 volts means the transformer is fine. If it is lower than that, there may be a problem with the voltage supply or the transformer. Leave the lead from the voltmeter in contact with the ground or common terminal on the transformer, and check the circuitry connected to the heater as well. Begin by checking the safety fuse, then the high limit switch and then the pressure switch. If the meter shows voltage, these parts are fine. If it does not, replace them.

Inadequate heating? If your swimming pool heater shuts off before warming the water to the desired temperature, it may be the result of a dirty filter or an improperly set timer. A dirty filter can prevent the heater from firing. The filter may need to be cleaned and the temperature switch to the ON position at a high enough setting that the heater turns on. Reset the timer to allow the heater to run for a longer period. Check the system’s valves as well to make sure that they are turned to go through the heater. If this does not resolve the problem, make sure you are using the right size of heater for your pool. If it is too small, it will not heat properly. The pool manufacturer’s product literature will recommend the right sized heater for your pool.

Noise? Sometimes your heater may make unusual noises such as bangs, whines or grinding. The first place to look is your systems hoses and filters. Debris can cause the heater to make knocking or whining noises during operation. Inspect the system for blockages and then back-flush the filter. A noisy heater can also indicate that it is operating after the pump shuts off, and this is related to a faulty pressure switch that needs to be replaced. Turn off the heater and contact a technician if you cannot find the source of the noise.

When to call a professional? A malfunctioning pool heater can be a serious safety hazard. If you are unsure about any situation or procedure, contact an expert or call your manufacturer for assistance. Do not attempt to repair electrical or gas issues by yourself. Malfunctioning gas valves and faulty wiring are jobs for professionals. Turn off power to the heater and call a technician if you have determined that the problem lies in these areas. In addition, if you cannot get your heater to shut off, this may indicate a dangerous problem that should be handled by a professional.