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The Home Depot

Why is My Pool Heater Not Working?

Pro Referral > Home Guides > Pool and Hot Tub > Why is My Pool Heater Not Working?
Why is My Pool Heater Not Working?

A heated pool is a luxury. Instead of forcing yourself to dive headfirst into frigid temperatures, you can let yourself easily slip into warmer, more comfortable waters. So, when you find that your pool heater has stopped working, it’s a bit of a buzz kill. You don’t want to cause your pool or your pool heater any more serious damage by attempting to fix it yourself. However, that doesn’t mean that you have to be completely in the dark about how your pool heater works.


We at Redbeacon have put together this handy guide as a kind of intro-to-pool heaters, to help you troubleshoot the source of the problem. Read on for what you absolutely need to know about why your pool heater isn’t working.

  1. 1. Check the system and switch the thermostat

    Make sure that your pool heater switch is on and the thermostat is set to the right temperature.

  2. 2. Filter

    Check to see if your pool filter is clean, because sometimes a dirty pool filter can have an effect on the heater. Most experts say that the filter should release pressure of 16 psi.

  3. 3. Gas valve

    Make sure your gas valve is on and that the supply valve is open. Also, if your pool is gas powered, make sure you have enough by checking the supply level on the tank.

  4. 4. Pump

    The pump must move water through the filter to get it to the heating element. Make sure your pump is operating correctly.

  5. 5. Heater pilot

    Is the pilot light lit? If not, you may have a problem with low gas pressure, inadequate air supply or improper venting. You should also check to make sure that you have enough gas.

  6. 6. Heater bypass

    The heater bypass helps make sure your pool’s heating element does not get flooded with too much water. Too much water can cause the heating element to become damaged and not work properly. So, the bypass (when it functions correctly) gets rid of the excess, unheated water.

  7. 7. Water corrosion

    If you have ever seen rust, you’ve seen how water can damage things. Even though the parts of your pool have been treated to withstand water damage, eventually corrosion will happen. If your pool is older, corrosion could be your problem. It can only be fixed by replacing the damaged parts.

  8. 8. Pressure switch

    The pressure switch ignites the heater. If your heater isn’t turning on, your pressure switch could be to blame.

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