Hurlcon Gas Heater F1 Error

hurlcon f1 error

Hurlcon Gas Heater F1 Error Solution Guide

My hurlcon heater displays the F1 error? Don’t stress it’s generally not a huge problem and it is quite normal for this to happen from time to time. This article explores the F1 error, what is it, why does it happen and how to fix it. This hurlcon gas heater F1 error article applies to all Hurlcon and Astral Pool heater models, WX75, WX120, HX70, HX120, JX130, JX160, MX125, MX150, MX200, MX250, MX300, MX400, MX500, both Natural gas and LPG models.

hurlcon F1 error - MX Heater

What is the Hurlcon F1 error?

The Hurlcon F1 error is a normal error notification from the heater advising you the pool or spa water is too hot, exceeding the 45° temperature limit and to wait for it to cool. In most cases when this happens its more likely to be a fault with heater parts than the water being too hot. In saying that when you get the F1 error you must check the heater operation and check the pool or spa water temperature manually with a thermometer device. This is a safety precaution and should be carried out before proceeding  further!

Once you have established the water is not too hot and the water is cold or below the set heater temperature and the F1 error is still showing then proceed. The F1 error is generated from the temperature sensor lead. This is the thermostat lead that connects from the digital thermostat PCB board on the front of the heater to the in/outlet manifold on the rear or side of the heater where the PVC pipes connect to it. Thermostat sensor lead locations are displayed in images further down on this article.

hurlcon f1 error

What causes the F1 error?

When water temperature rises above the heater temperature limit of 45° the F1 error will appear on the digital display, it will flash repeatedly. It will flash or display until the water has cooled below the set temperature. In other cases the F1 error will display when there is a problem with the thermostat sensor lead itself. The sensor lead could be cut, could be melted and fused together or it could be corroded by water. This will totally destroy the thermostat lead. The thermostat sensor lead tip sits in the brass sensor pocket that’s located on the inlet water manifold. Over time water can condensate and fill the brass pocket and eventually corrode through to the sensor lead tip and destroy it. The other common cause is the water balance in the pool or spa, is in poor unbalanced condition! This will corrode right through the brass sensor pocket and then eat into the sensor lead tip and totally destroy it.

F1 Temperature Senor Lead locations?

The heater thermostat lead is located in the brass pocket located on the in/outlet manifold where the water enters the heater. The manifold is located on the rear or side of the gas heater. You will need to remove the top metal panel that is above the water manifold. The HX heaters metal panel lifts up and out at the bottom. For the JX heaters you will need to remove the small metal panel located on the bottom of the heater, left hand side. The MX heaters will need the top metal panel above the water manifold removed. They have screws that you will need to removed and then the panel lifts out towards you. Inspect the parts and if you see any corrosion on any part of the thermostat sensor lead or the brass pocket then you will need to replace them.

hurlcon HX thermostat sensor lead location

hurlcon MX thermostat sensor lead location

Hurlcon F1 Error -JX Sensor location


How to Fix a Hurlcon Heater F1 Error

First thing to do is to unplug the heater power cord from the power point and wait 10 seconds and then plug in again. Performing this operation resets the heater ignition system which can sometimes remove the F1 error. Now start the water pump back up and once its running turn it on and watch the heater go through its start up process. If the heater fires up that’s great nothing else will be needed but if the F1 error pops up again turn the heater off. Now you need to inspect the thermostat lead and the brass sensor pocket on the manifold.

You will need to remove the top metal panels above the water manifold to get to the thermostat sensor lead and brass pocket.

Do not cut and rejoin the the wire like this image below, this will not work. You will need to replace the entire thermostat lead. You can see that the thermostat lead is enclosed in a heat shield flexible tube. The new lead needs to be fed though this tubing to protect it from the heat. If you do not the lead will melt.

hurlcon F1 heater error

NOTE: If your heater is located lower than the water level of the pool or spa make sure to close water pipe valves so water does not leak from heater when you replace the thermostat lead or the brass sensor pocket.

1 – Turn power off to the heater and unplug it from the power supply.

2 – Remove the top rear or side panel above the water in and outlet manifold.

3 – Remove the the side metal panel if required.

4 – Locate the thermostat sensor lead and lift it out of the brass sensor pocket. It may have a cable tie and silicone around the edge, pull that off.

5 – Now remove the front metal panel that the digital display board is connected to.

6 – Look on the rear of the circuit board and locate the sensor lead wire connector. UN-clip if from the PCB.

7 – Now follow the sensor lead that’s encased in the heat shield. It may be cables tied to the heater burner frame? Remove those cable ties.

8 – Once it is free now you can pull out the complete lead in the heat shield.

Now you are ready to feed the new sensor lead into the heat shield and re install the lead. Connect it back into the PCB and into the brass sensor pocket. Silicone & cable tie it back and re attached all panels.

Do You Need To Install a New Brass Pocket as well??

NOTE: If you find the thermostat lead is rusted to the brass pocket and you cant remove the lead freely just cut the sensor lead with some pliers.

9 – Use a small shifting spanner and turn the brass sensor pocket anti-clockwise to unloosen it and remove it from the inlet manifold.

10 – Place some thread tape around the brass sensor pocket thread and screw it back into the inlet manifold. Do not over tighten!


Replacement Parts You Will Need to Fix The F1 Error

The main part to order that fixes the F1 error is the thermostat sensor lead which can be found here – F1 Thermostat Sensor Lead

In 99% or cases you will need to replace both the temperate sensor lead and the brass sensor pocket, heres the link to the brass sensor pocket only – Thermostat Brass Sensor Pocket

In some rare cases these parts may need replacement as well –
The thermostat PCB display board may need replacement. This part can be found here – Hurlcon Thermostat PCB
The inlet 45° hi limit sensor may need replacement as well.This part can be found here – 45° Hi Limit Sensor

Need more help with the Hurlcon gas heater F1 error? – Book a Service

This Hurlcon F1 error article is for information purposes only. HeaterFix recommends all gas heater repairs, servicing and replacements to be carried out by a professional licensed gas fitter. If you need help regarding your gas heater you can make a from the form below.

Pool/Spa Information

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3 - The digital display ON (so we can see any error codes)
4 - The water connections to the heater (so we can see how it is plumbed)

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