Hayward Pool Heater Code 10: Ignition Failure Lockout

Quick Answer

Hayward Code 10 is an ignition failure lockout on FiPro and some H-Series models. The heater tried to ignite multiple times and could not confirm a flame via the flame sensor. Gas supply issues and a dirty flame sensor together account for 70% of Code 10 faults.

Code 10 usually shows up on that first spring startup or right after a propane tank refill. It means the board tried to light the burner three times and couldn't confirm a flame. Don't panic though. I've seen this exact situation dozens of times and it's usually just oxidation on the sensor rod or a gas valve someone left closed. If you hear clicking but no fire, start with gas pressure.

HaywardPoolheaterSeverity: highDifficulty: intermediate75% DIY Success

Time to Fix

30–150 min

Difficulty

intermediate

Parts Cost

$15 – $300

Tools Needed

Digital multimeter with AC/DC voltage and ohms, Fine steel wool (#0000 grade)

What Does the 10 Code Mean?

When I see Code 10 on a Hayward unit, I stop and listen first. You should hear the inducer fan kick on, then the igniter glow up, then the gas valve click open. If that sequence breaks down anywhere, the board shuts it all down. It's the heater's way of saying it won't keep dumping gas into a chamber that isn't lighting. Smart safety feature, honestly.

Most Likely Causes

Based on aggregated repair data, here is the probability breakdown for this error code:

Gas supply shut off or insufficient pressure at the heater40%

Dirty or corroded flame sensor rod24%

Failed hot surface igniter14%

Debris blocking burner orifice12%

Gas valve not opening (failed coil or wiring)10%

Symptoms You May Notice

The display shows Code 10 after you hear the full startup sequence run, fan, igniter clicking, gas valve click, and then nothing.
Blower fan runs fine, you might catch a brief whiff of gas, but no flame ever establishes and the heater just cuts out cold.
The heater tries to spark two or three times, maybe lights for half a second, then gives up and locks out.
Pool water stays cold even though the heater's been 'running' all afternoon.
Code 10 appears on the very first startup of the season after months of sitting idle on the equipment pad.

Can you reset a Hayward poolheater to clear the 10 code?

To clear the lockout, press the Mode button to cycle the heater to standby and then back to heat mode. But if it's tried to fire multiple times, just go to the breaker and flip it off for a full 60 seconds. That clears the board's memory completely. After you restore power, wait for the display to come back up before calling for heat. That full reset is usually necessary after you've fixed whatever caused the lockout.

Tools Required for Diagnosis

Digital multimeter with AC/DC voltage and ohmsFine steel wool (#0000 grade)Phillips #2 screwdriverFlat-head screwdriverNeedle-nose pliersWork gloves

Diagnostic Checklist

Follow these steps in order. We start with the easiest external fixes before opening up the machine.

ComponentComponent Under Test

Expected Range50–200 ohms

ConditionIf Open (OL) or infinite, replace component.

Replacement Parts

If your diagnostic testing proves the component has failed, you will need a replacement. We recommend OEM parts over aftermarket for water-handling components.

Part Name	OEM Number	Estimated Price
Hot surface igniterCHXIGN003 · $25–$60	CHXIGN003	$25 – $60
Flame sensor / flame rodCHXFIR002 · $15–$35	CHXFIR002	$15 – $35
Gas valveCHXVAL003 · $120–$300	CHXVAL003	$120 – $300

Frequently Asked Questions

What does Code 10 mean on a Hayward pool heater?

Code 10 is a safety lockout that fires when the heater can't confirm a flame exists after three tries. The control board stops attempting to ignite so raw gas doesn't pool in the burner tray. It's essentially the heater saying it tried but it's not safe to keep going. Most of the time the flame actually lights for a second or two, but the sensor's too dirty to report back to the board, so the board doesn't know it happened.

How do I fix Code 10 on a Hayward pool heater?

Start with the flame sensor. It's a ten-minute job that costs you nothing. Clean the rod with steel wool until it's shiny, do a full reset, and try again. If that doesn't fix it, check your gas supply and then the igniter. About 90% of the Code 10 calls I run are fixed by either opening a gas valve someone left closed or cleaning that one little sensor rod. Seriously, don't skip that step just because it sounds too simple.

Is Hayward Code 10 the same as the IF code?

They're functionally the same thing. Hayward updated their displays on newer FiPro models to use numeric codes like 10, while older H-Series units use IF, which stands for Ignition Failure. The diagnostic path is identical for both. If you're seeing either one, you're looking at a system that couldn't verify a successful burn, and you work through the same checklist either way.

How do I clean the Hayward pool heater flame sensor?

First, kill the power and gas at the heater. You'll find the sensor held in by one screw near the burner assembly. Once it's out, scrub it with fine steel wool until you see shiny bare metal, not that dull gray oxidation coating. Be gentle because you don't want to bend the rod or crack the ceramic insulator at the base. Pop it back in, reconnect the wire, and you're usually back in business within a few minutes.

Can low gas pressure cause Code 10 on a Hayward heater?

Absolutely. These heaters are gas hogs. If your supply line's undersized or your regulator is starting to fail, the pressure drops the moment that valve opens and you just can't sustain a flame. If you hear chugging or a whooshing sound right before the code appears, that's a classic low pressure situation. Get a manometer on the gas line and check static and operating pressure. Should be around 11 inches water column for natural gas, closer to 11 to 14 for propane.

How much does it cost to fix Code 10 on a Hayward pool heater?

Depends on the cause. Cleaning the flame sensor costs you nothing but 20 minutes of your time. A new igniter runs $30 to $80 in parts and you can swap it yourself in about an hour. Gas valve replacement is $150 to $350 for the part alone. If you're calling a tech out, add $100 to $200 in labor. Most Code 10 repairs come in under $150 total if you catch it at the sensor or igniter stage, which is most of the time.

Related Hayward Poolheater Error Codes

Code: HUBHayward Pool Heater Error Codes Guide Code: IFHayward Pool Heater IF Error Code Code: RESETHow to Reset a Hayward Pool Heater

Same Fix on Other Brands

Pentair poolheaterERR IGN: Pentair Pool Heater ERR IGN Error

Models Known to Experience 10 Errors

This repair applies to most Hayward poolheaters with this error code. Common model numbers include:

H100FDN, H150FDN, H200FDN, H250FDN, H300FDN, H350FDN, H400FDN, H400FDP

Written by

Raj Patel

HVAC & Water Systems Specialist · 15 years experience

Last verified for technical accuracy on March 14, 2026