Pool & Hot Tub Reviews Best Ratings l Blue Waters Pool Service

Troubleshoot Pool Heaters

When you purchase a swimming pool heater that is under a manufacturer’s warranty, you are not allowed to troubleshoot the heater yourself if it is not working correctly. Doing so could void the warranty. However, if the warranty has already expired on your pool heater, then you could probably save a lot of money by fixing it yourself.

Let’s take a look at the four most common issues that cause swimming pool heaters to stop working correctly and the best remedies for these issues.

The Heater Does Not Ignite

Ignition failure happens a lot with pool heaters. Before you investigate the matter, make sure the heater is turned on. Now set a higher temperature on the thermostat than the current temperature of the pool water.

Next, take a look at your fuel filter and fuel pump. Are they dirty? If so, then you must clean them out thoroughly.

Light the pilot if it is not lit already. Do you notice the pilot light going out quickly? If so, it could have something to do with the venting, gas pressure, or air supply. Check out these areas of the heater to see if they’re causing a problem.

You cannot have a functional heater without a steady flow of gas. Check the gas supply valve and make sure it is turned to the “ON” position. Also, all the valves for the filter and plumbing should remain open as well.

The Water Flow is Too Low

A pool heater needs water to flow through it consistently to stay operational. The latest pool heaters contain special pressure sensors that can determine when there are changes to the water flow. 

If the water flow ever gets to be too low, then a warning message will appear on the LCD screen of the heater. Either that or you’ll notice warm water is not coming out of your heater as much as it should be. Do not panic when this happens because it is more common than you might think.

First, check the pressure gauge of your pool filter to get the current PSI reading, which is the pressure reading. High PSI means your filter needs to be cleaned because the heater needs more pressure when there is less water flow. A clogged filter obviously restricts water flow, which is why it must be cleaned. 

If the filter is not the problem, then perhaps the pump basket needs to be cleaned instead. This is the strainer basket inside of the pump. Take out the basket and clear out any debris in it. You can use a garden hose for this task. Before you reinstall the basket and its lid, check to see if they have any cracks in them. If they do, then replace them immediately.

Other Tips

Does your swimming pool use a lot of other water features simultaneously? It could be what is restricting water flow to the heater if this is the case. Your pool pump cannot handle too much demand, so you need to reduce the demand by removing any unnecessary water features. But if you insist on having more features, then get a bigger motor for your pump. Either that or alternate when you use certain features so that you don’t use them simultaneously.

Pool heaters require a certain number of gallons per minute (GPM) to flow through them. If you’re using a variable speed pump, check to see if it’s pumping the minimum gallons per minute required for your heater. If it’s not, then you probably have the heater on a low setting.

If you’ve followed all of this advice and still have low water flow, then your pressure sensor is likely defective. Your pressure sensor checks to see if the pool water is flowing into the heater before it gets turned on. A faulty pressure sensor might prevent the proper water flow level from being detected. 

If you have a clean pool filter and you’ve activated your pool pump, then your pool pressure sensor should have the ability to receive voltage. Use a multimeter to test how much voltage is passing through the pressure switch. If there is little to no voltage detected, then it must mean you have a bad pressure sensor. Replace it immediately.

The Heater Cycles Between the On and Off Power Setting

Does your swimming pool heater keep shutting off and turning on automatically? If so, then you could have a problem with your power supply or electrical connection. If not, then perhaps the water chemistry of your pool is not balanced correctly. Check the manual of your pool heater to determine the correct water balance for it. If you don’t maintain the chemical levels correctly, then it could damage your heater.

Another thing you should do is inspect the components of your heater, such as the pressure sensor, high limit switch, and thermal regulator. If they appear to be defective or corroded, then replace them at once. Sometimes the heat exchanger will suffer chemical damage over a period of time, so check its condition too.

And, of course, clean your pool filter if it is dirty. When a clogged pool filter causes water pressure to decrease, it could force the pressure sensor or the entire heater to shut down. Cleaning or replacing the pool filter is one of the easiest ways to ensure that the heater does not cycle on and off by itself.

The Pool Heater Does Not Heat the Water

Even if the pilot ignites in your pool heater, you might still find the pool heater is unsuccessful in heating your pool water. If that’s the case, check on the temperature sensor to see if it works or is installed correctly. Your thermostat should also get set to a higher temperature.

If none of these steps helped, then your heater must be too small for the size of your pool. It is always better to use a large heater with a smaller pool than a small heater with an oversized pool.