Hayward Pool Heater Troubleshooting: Fix It Fast!

Hayward pool heater troubleshooting involves checking for low gas pressure, inadequate air supply, improper venting, a dirty filter, or closed valves that may cause the heater to not ignite or turn on properly. It is essential to ensure that the gas is turned on and that there is enough fuel in the tank for propane heaters.

Additionally, checking for water run-off from the roof or sprinklers that may flood the heater is crucial. The heater may also cycle on and off due to inadequate water flow caused by a dirty filter, closed valves, external bypass adjustments, or reversed water connections.

Troubleshooting steps for specific diagnostic codes can be found in Hayward’s Universal H-Series Diagnostics Manual.

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Common Issues With Hayward Pool Heaters

Hayward pool heaters are known for their reliability and performance. However, like any other appliance, they may experience issues from time to time. Understanding the common problems that can occur with Hayward pool heaters can help you troubleshoot and resolve any issues quickly, keeping your pool warm and comfortable all year round.

Heater Not Igniting

One common issue that pool owners may face is a heater that fails to ignite. If your Hayward pool heater is not igniting, it could be due to several reasons:

  • Low gas pressure
  • Inadequate air supply
  • Improper venting

To resolve this issue, you should first check if the gas is turned on and ensure that there is enough fuel in the propane tank. Additionally, inspect the heater for any water run-off or flooding caused by a roof leak or sprinklers. If you still can’t get the heater to ignite, it may be necessary to call a professional for further assistance.

Heater Not Turning On

If your Hayward pool heater is not turning on at all, the most common culprit is a dirty swimming pool filter. A clogged filter can restrict water flow, preventing the heater from starting up. To troubleshoot this issue, clean or replace the pool filter and pump basket. Additionally, ensure that all valves are open and check for any blockages in the water circulation system.

Heater Cycling On And Off

Another common problem with Hayward pool heaters is when they cycle on and off frequently. This issue can be caused by various factors:

  • Inadequate water flow due to a dirty filter or closed valves
  • External bypass in need of adjustment
  • Reversed water connections

To address this issue, start by cleaning or replacing the pool filter and ensuring that all valves are open. If the problem persists, check the external bypass and adjust it if necessary. Lastly, make sure that the water connections are properly installed and not reversed. If you are still experiencing issues, it is recommended to contact Hayward Pool Products for further assistance.

Troubleshooting Steps

If you’re experiencing issues with your Hayward pool heater, there are several troubleshooting steps you can take to identify and resolve the problem. By following these steps in a systematic manner, you can potentially save time and money by avoiding unnecessary repairs or replacements. Below are some common issues and the corresponding troubleshooting steps for each one.

Check Gas Pressure And Fuel Supply

One possible cause for a Hayward pool heater not firing up is low gas pressure or inadequate fuel supply. To troubleshoot this issue:

  1. Ensure that the gas valve is turned on.
  2. For propane heaters, make sure the tank has adequate fuel.
  3. Check for any water run-off from the roof or sprinklers that may be flooding the heater.

If the gas pressure and fuel supply are not the problem, move on to the next troubleshooting step.

Inspect Air Supply And Venting

Inadequate air supply or improper venting can prevent a Hayward pool heater from igniting. To troubleshoot this issue:

  1. Ensure that there is proper air flow around the heater.
  2. Check for any blockages or obstructions in the venting system.
  3. If the venting system is not functioning correctly, it may be necessary to contact a professional for repairs.

If the air supply and venting are not the issue, move on to the next troubleshooting step.

Ensure Proper Water Flow

Inadequate water flow can cause a Hayward pool heater to cycle on and off or not heat up sufficiently. To troubleshoot this issue:

  1. Check the filter and pump for any dirt or debris that may be blocking the water flow.
  2. Clean or replace the filter if necessary.
  3. Ensure that all valves are fully open and not restricting the water flow to the heater.

If the water flow is not the problem, move on to the next troubleshooting step.

Clean Filters And Pump

Dirty filters and pumps can affect the performance of a Hayward pool heater. To troubleshoot this issue:

  1. Turn off the heater and the pump.
  2. Remove and clean the filter according to the manufacturer’s instructions.
  3. Inspect the pump for any debris or clogs and clean if necessary.
  4. Reinstall the filter and restart the pump.

If cleaning the filters and pump does not resolve the issue, move on to the next troubleshooting step.

Adjust External Bypass If Needed

An incorrectly adjusted external bypass can cause inadequate water flow and poor heating performance. To troubleshoot this issue:

  1. Locate the external bypass valve.
  2. If the valve is partially closed, open it fully.
  3. If the valve is fully open, close it partially to increase water flow if needed.

If none of these troubleshooting steps solve the problem with your Hayward pool heater, it may be necessary to consult a professional for further assistance.

Tips For Diagnosing Problems

When your Hayward pool heater is experiencing issues, it can be frustrating to figure out what’s causing the problem. However, with these helpful tips, you can effectively diagnose the issues and get your pool heater back up and running in no time.

Follow The Heater Start Sequence

It’s important to follow the correct start sequence when troubleshooting your Hayward pool heater. By following the proper steps, you can ensure that all components are functioning correctly and eliminate any potential issues.

Refer To The Diagnostic Codes Manual

If your Hayward pool heater is displaying diagnostic codes, it’s crucial to consult the diagnostic codes manual. This manual provides valuable information about the specific codes and their meanings, allowing you to pinpoint the exact problem.

Identify Specific Code Descriptions

Table 1:

Code Description
LO Ignition Failure Lockout
FLAME SENSOR Flame sensor fault
HEAT EXCHANGER Heat exchanger issue
GAS VALVE Gas valve problem
WIRING DIAGRAM Wiring diagram error

Being able to identify specific code descriptions can give you valuable insights into what exactly is causing the problem with your Hayward pool heater.

Go Step-by-step To Determine Failure Point

When troubleshooting your pool heater, it’s essential to go step-by-step to determine the failure point. By systematically checking each component and verifying its functionality, you can identify the exact area where the problem lies.

Check Gas Pressure At The Gas Valve

One common issue with Hayward pool heaters is insufficient gas pressure. To rule out this possibility, it’s crucial to check the gas pressure at the gas valve. Ensure that the pressure is within the recommended range to ensure optimal performance.

Additional Resources For Troubleshooting

If you’re experiencing issues with your Hayward pool heater, don’t fret! There are several resources available to help you troubleshoot and resolve the problem. Whether you’re looking for in-depth troubleshooting guides, informative articles, or expert advice, these resources have got you covered.

Hayward Pool Products Troubleshooting Guide

The official Hayward Pool Products website offers a comprehensive troubleshooting guide to help you diagnose and fix common issues with your pool heater. This guide provides step-by-step instructions and useful tips to ensure that you can get your heater back up and running in no time.

In The Swim Pool Blog Articles

In The Swim’s Pool Blog features a wide range of articles focused on pool maintenance, including troubleshooting tips for Hayward pool heaters. These informative articles are written by experts in the field, providing practical advice and solutions to common heater problems.

Poolheatpumps.com Troubleshooting Guide

Poolheatpumps.com offers a detailed troubleshooting guide specifically tailored to pool heat pumps, including those manufactured by Hayward. This guide covers a variety of issues and provides step-by-step instructions, helping you identify and resolve problems efficiently.

Trouble Free Pool Forum Threads

The Trouble Free Pool forum is a community of pool owners and enthusiasts who share their experiences and knowledge. This forum features dedicated threads on Hayward pool heater troubleshooting, where you can find valuable insights, practical solutions, and advice from fellow pool owners.

Doityourself.com And Justanswer.com For Expert Help

If you’re still facing difficulties after exhausting the aforementioned resources, DoItYourself.com and JustAnswer.com are great platforms to seek expert help. These websites connect you with professionals who can provide personalized advice and guidance to troubleshoot and resolve any complex issues you may encounter with your Hayward pool heater.

Preventive Maintenance And Tips

Proper preventive maintenance is essential to keep your Hayward pool heater in optimum working condition. By following these maintenance tips, you can ensure its longevity and efficiency.

Regularly Clean And Inspect Flame Sensor

The flame sensor is responsible for detecting the presence of a flame. Over time, it can accumulate dirt and debris, which may impact its performance. To prevent any issues, it is important to regularly clean and inspect the flame sensor. Use a soft cloth or brush to gently remove any buildup, making sure it is free from any obstructions.

Monitor And Maintain Proper Water Flow

Proper water flow is crucial for the efficient operation of your pool heater. Ensure that the water flow rate is within the recommended range for your specific model. Periodically check the pump and filter to ensure they are clean and functioning properly. If you notice any decrease in water flow, address the issue promptly to prevent any heater malfunctions.

Clean And Replace Filters As Needed

Filters play a significant role in maintaining clean and clear pool water. Over time, filters can become clogged with debris, which can impact the performance of your pool heater. Routinely clean and rinse your filters, and replace them when necessary. This will not only improve the efficiency of your heater but also extend its lifespan.

Schedule Professional Maintenance At Least Once A Year

While regular maintenance can be performed by the pool owner, it is important to schedule professional maintenance at least once a year. A certified technician will thoroughly inspect and service your Hayward pool heater, identifying any potential issues before they become major problems. This will ensure that your heater continues to operate efficiently and effectively.

Keep The Pool Heater Area Free From Debris

The area around your pool heater should be kept clean and free from debris. Leaves, branches, and other debris can easily find their way into the heater, obstructing airflow and affecting its performance. Regularly clean the area and ensure there are no obstructions. This will help your heater to function optimally and reduce the risk of any malfunctions.

Frequently Asked Questions

Why Is My Hayward Pool Heater Not Firing?

Possible answer: Pool heater not firing? Check gas pressure, air supply, and venting. Ensure gas is on and propane tank has fuel. Watch for water run-off or flooding. Dirty filter or closed valves can cause inadequate water flow. Adjust external bypass and check water connections.

Troubleshoot using Hayward’s diagnostics manual.

What Would Cause Pool Heater To Not Ignite?

Possible causes for a pool heater not igniting include low gas pressure, inadequate air supply, or improper venting. Make sure the gas is turned on, and for propane, ensure the tank has fuel. Also, check for water run-off from the roof or sprinklers that may be flooding the heater.

Why Wont My Pool Heater Come On?

A dirty swimming pool filter can restrict water flow and prevent the pool heater from turning on. Make sure to clean the filter and check for any other issues such as low gas pressure or improper venting.

Why Is My Hayward Pool Heater Turning On And Off?

A dirty filter, closed valves, inadequate water flow, or reversed water connections might be causing your Hayward pool heater to turn on and off. Make sure to check these issues for proper functionality.

Why Is My Hayward Pool Heater Not Firing?

Heater pilot won’t light? This could be due to low gas pressure, inadequate air supply, or improper venting. Make sure gas is turned on; and for propane, make sure the tank has fuel. Also check for water run-off from roof or sprinklers that may be flooding the heater.


If you’re having trouble with your Hayward pool heater, don’t worry! By following the troubleshooting steps mentioned in this blog post, you’ll be able to diagnose and fix any issues that may arise. Remember to check the filter, ensure proper gas pressure and ventilation, and inspect any potential water run-off.

By addressing these common problems, you’ll be able to enjoy a warm and inviting swimming pool all season long. Don’t hesitate to reach out to Hayward Pool Products for further assistance. Keep your pool heater running smoothly and enjoy endless hours of relaxation in your backyard oasis.

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