Why Jandy Pool Heater Won’t Ignite [9 Easy Fixes]

There can be several reasons why your Jandy pool heater won’t ignite. An error message saying ‘CHECK IGN CONTROL’ can appear when this issue occurs.

The possible causes include- fluctuating filter pump pressure, faulty flame sensor, bad pressure sensor, damaged fan/switch tubing, fan not operating or running slowly, restricted airflow, low gas supply pressure, malfunctioning gas valve, and air in the gas line. 

Keep reading our Jandy JXi pool heater troubleshooting guide to get your heater started ASAP.

Table Of Contents

Jandy Pool Heater Won’t Ignite [9 Easy Fixes]

In this section, we will take a deeper look at the possible reasons why your Jandy pool heater won’t ignite and provide you with the simplest solutions.

1. Fluctuating Filter Pump Pressure

Fluctuating filter pump pressure can cause the pump to burn out, lower water flow, and filter pressure problems.

This issue can be a result of air leaks, low water levels, stuck skimmer weirs, or clogged suction pipes. Varying pump pressure can cause your Jandy JXi pool heater not to ignite.


You can start by cleaning your pool filter. If backwashing the pool filter doesn’t help you, you need to identify which of the reasons mentioned above is causing the issue.

  • Make sure your pump lid is free of cracks and the O-ring is smooth and undamaged to ensure a perfect seal and no air leaks. Also, replace any damaged or cracked fittings leading into the pump.
  • If needed, simply add enough water to your pool to reach the proper levels, and your surge or pump pulsing problem should be resolved in no time.
  • Check to see if your weir’s hinges are still working properly and repair any damaged or jammed doors.
  • To clean blocked suction pipes, take a high-pressure attachment or drain king. Connect it to the pool pump’s front to send the debris out to the skimmer box.

2. Faulty Flame Sensor

The flame sensor is used as protection against gas leaks. The flame sensor is an electrode that the ignition control uses to detect the “rectification” of current flowing through the flame.

Only after detection does the gas valve open to light up the burners. So, if you have a faulty flame sensor your Jandy LXi pool heater won’t ignite


Connect a multimeter that can measure microamps (A) in series between the sensor terminal and the wire that feeds to the gas valve to see if the flame sensor is delivering a signal to the gas valve. This test must be carried out with the power turned on.

Remove the flame sensor’s lead and connect it to one of the meter’s probes. Connect the sensor terminal to the other meter probe.

When the burners ignite, raise the thermostat and examine the reading. The reading should be between 5 and 10 A. If it reads less, the sensor is defective and must be replaced.

3. Bad Pressure Switch

By detecting back pressure inside the heat exchanger, this control determines whether or not water is available to the heater.

The pressure switch prevents the burner from operating if the pool water pump fails or the water filter becomes clogged.

A bad pressure sensor may be why your Jandy Lite2 pool heater won’t turn on even when the pump and filter are fine.


You need to test the pressure switch for continuity with a multimeter. Here’s how.

Set the multimeter to the Ohms setting. Ensure that you’re monitoring the single ohms setting. To test for Ohms, double-check that the leads are in the appropriate spot, then grab the switch.

You’ll notice a side with different terminals when you turn the pressure switch around. If there are no terminals visible, you may need to remove the cover first.

Get the leads and connect one on each terminal once you’ve located the terminals. A closed switch must have a resistance of 0 Ohms. You’re dealing with a defective switch if you see ‘infinity.’ Replace the pressure switch if necessary.

4. Bad Igniter

When electrical power is added to the hot surface igniter, it transforms into a crystalline element that gets extremely hot.

The air/gas mixture in the combustion chamber is immediately ignited by the hot surface igniter. So, without a working igniter, you can’t get your Jandy pool heater to light up.


You need a multimeter to see if the igniter is broken. First, ensure that the multimeter is set to the test with the lowest resistance.

Then, connect the probes to the tips of the igniter plug. If the multimeter reads infinity or zero, the ignitor is broken and needs to be replaced.

5. Fan Not Operating Or Running Slow

For your pool heater to run, you need the fan to run at a certain pace. Without good airflow, your Jandy JXi pool heater won’t ignite.


Check to see if the fan is operating. If not, the blower motor may be at fault. The problem may also be in the wiring or the blower may be getting an inadequate voltage supply.

You need to figure out which of these possible things are wrong with the blower. To inspect the wiring connections, refer to the Jandy pool heater wiring diagram below.

6. Restricted Air Flow

If the vents are restricted at the intake or exhaust, your heater may not ignite. That is because you need adequate airflow for ignition.

The airflow switch is a safety device that trips when the heater isn’t getting enough airflow. So, your heater won’t light up if the airflow is restricted.


Check for correct clearances around the heater and, if the room is enclosed, adequate ventilation. Examine the flue discharge for blockages or restrictions.

Trees or other objects that would restrict unobstructed air passage to and from the vent terminal should be far away from the vent aperture. Make sure that the vents are not placed beneath decks, stairways, or automobile ports.

7. Low Gas Supply Pressure

Low gas supply pressure can also cause a Jandy JXi pool heater ignition fault.


Check the gas supply to make sure it matches the gas specified on the heater’s rating plate. 

During pressure testing of the system at pressures more than 1/2 pound per square inch (psi) (3.45 kilopascals [kPa]), disconnect the heater and its individual shutdown valve from the gas supply system.

During the piping pressure test, close the manual shutdown valve on the heater if the test pressure is equal to or less than 1/2 psi (3.45 kPa).

Check for an undersized pipe between the meter and the heater, a restrictive fitting, or an undersized gas meter if the gas supply pressure is less than required. The table below shows the required gas supply pressure.

Supply PressureMinimumMaximum
Natural Gas5.0 inches W.C. [1.2 kPa]10.5 inches W.C. [2.6 kPa]
LP Gas11.0 inches W.C. [2.5 kPa]14.0 inches W.C. [3.5 kPa]
Manifold PressureNominal
Natural Gas2.5 inches W.C. [0.6 kPa]
LP Gas9.0 inches W.C. [2.2 kPa]

8. Malfunctioning Gas Valve

The gas valve regulates the flow of gas into the manifold. It only allows flow when the temperature control requires heat and all safety safeguards are in place

. So, when your gas valve malfunctions, the heater doesn’t light up.


Look at the top or side of the gas valve for the two wires attached to the solenoid terminals. Remove the wires from the terminals of the gas valve.

Each wire is attached to a push-on clip that can be removed from the terminal. Make a note of where the wires join the valve so you can reconnect them later. 

Set the multimeter’s test control to “mV,”. Connect each tester probe on the multimeter to each of the gas valve’s terminals.

A typical reading will be between 145 and 195 millivolts. In case the noted reading is not within this range, the gas valve is faulty. You will have to replace it. 

9. Air In Gas Line

Your heater will not ignite correctly if there is air in your gas line. It could be the cause of your water heater’s inability to stay lit.


The best method is to remove the air from the gas line. Locate the hose bib to bleed away air after shutting off the water heater.

To connect the hose to the bib, turn it clockwise. Drain the water into the grass. You can stop after draining the tank until clean water starts to come out and there is no sputtering.


Why is my Jandy heater not working?

A tripped breaker or fuse is one of the most typical causes. Check the fuse or reset the breaker. Call for service if the heat pump is still not working. 

How long is a Jandy pool pump warranty?

For one (1) year from the date of retail purchase, Zodiac Pool Systems LLC (“Zodiac”) warrants all Jandy branded pool heaters to be free of manufactured defects in materials and workmanship.

What causes a pool heat exchanger to fail?

Long-term exposure to high amounts of free chlorine (more than 5 ppm) will induce degradation and premature heat exchanger failure.

How do I contact Jandy?

You can call Jandy customer care Monday through Friday, 8 AM-5 PM (PST) on this number- 800.822.7933 or send an email to the following address-  productsupport@fluidra.com 

What does ENA mean in a Jandy pool heater?

ENA indicates that the heater is turned on but not running because it is not required. The water is not warm enough or the pump is not operating. The heater will turn on if the pump is running when the water temperature falls below the set point.


Hopefully, now you have the answer to your question, “Why is my Jandy pool heater not working?”.

In case you still have queries about your Jandy pool heater, you can leave us a comment. Our expert will give you an answer ASAP.

Note: You can also read how to fix Pentair heater not turning on problem.

About David

David is a man who loves doing research and finding out the best solution to any type of heating appliance issues like heaters and fireplaces. Whenever he finds the perfect solutions to any issues of heating appliances after doing in-depth research, he loves to share them with his readers. In fact, his aim is to help his readers to fix the issues with their heating appliances easily.More about us .

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