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Australia's Pool Heater Specialists

Hayward H400 Heater Parts

Hayward H400 heater parts are used to repair and maintain Hayward H400 gas pool heaters. Common replacement parts include thermistors, ignition modules, gas valves, pressure switches and control boards.

This collection includes genuine and compatible Hayward H400 gas heater parts designed to restore heating performance, resolve faults and extend heater lifespan.

If your Hayward H400 heater is not operating correctly, view our troubleshooting guides, return to our Hayward gas heater parts hub or book a pool heater repair.

Read More About Hayward H400 Heater Parts

Common Hayward H400 Heater Parts

  • Thermistors and sensors
  • Ignition modules and flame controls
  • Gas valves and burners
  • Control boards
  • Pressure switches

Common Hayward H400 Heater Faults

  • Ignition failure
  • Temperature control issues
  • Lockout faults
  • Gas flow problems
  • Water pressure faults

Hayward H400 Heater Parts – FAQs

What parts fail in Hayward H400 heaters?
Common failures include thermistors, gas valves and control boards.

Is the H400 heater repairable?
Yes, most faults can be fixed by replacing individual components.

How do I confirm my heater model?
Check the data plate on the unit for the H400 model number.

Can I install parts myself?
Basic parts can be replaced, but gas and electrical components require a qualified technician.

  • Hayward Gas Heater Thermistor

    Hayward Gas Heater Thermistor

    $115.00
    $115.00
    $115.00
    $115.00

    Hayward Gas Heater Thermistor — Genuine temperature sensor for Hayward FD-series heaters. Delivers accurate water temperature feedback for stable h...

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    $115.00
    $115.00
    $115.00
    $115.00
  • Hayward H150 Wiring Harness 50Hz H150 - Gas Heater Spare Part

    Hayward Wiring Harness 50Hz

    $323.89
    $323.89 - $355.03
    $323.89
    $323.89

    The Hayward Wiring Harness50hz H150 is a genuine Hayward replacement part that connects and routes electrical power between heater components. Desi...

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    $323.89
    $323.89 - $355.03
    $323.89
    $323.89
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  • Hayward_Water_Pressure_Switch

    Hayward Water Pressure Switch

    $155.47
    $155.47
    $155.47
    $155.47

    The Hayward Water Pressurer Switch is a genuine Hayward replacement part that detects water flow and pressure to protect the heater from dry firing...

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    $155.47
    $155.47
    $155.47
    $155.47
  • Hayward H150 Wiring Harness 50Hz H150 - Gas Heater Spare Part

    Hayward Upper End Cap

    $247.11
    $247.11
    $247.11
    $247.11

    The Hayward Upper End Cap - is a genuine Hayward replacement part that is an essential component for correct heater operation. Designed specifical...

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    $247.11
    $247.11
    $247.11
    $247.11
  • Hayward_50_HZ_FD_Transformer

    Hayward Transformer Kit 50 Hz

    $245.15
    $245.15
    $245.15
    $245.15

    The Hayward Transformer Kit 50 Hz is a genuine Hayward replacement part that converts mains voltage to low voltage for the heater control circuit....

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    $245.15
    $245.15
    $245.15
    $245.15
  • Hayward_Gas_Heater_Top_Front_Panel

    Hayward Top & Front Panel

    $188.46
    $188.46 - $231.94
    $188.46
    $188.46

    The Hayward Top & Front Panel - H150 is a genuine Hayward replacement part that forms part of the heater cabinet, providing protection and weat...

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    $188.46
    $188.46 - $231.94
    $188.46
    $188.46
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  • Hayward Top & Flue Cover

    $185.23
    $185.23 - $247.51
    $185.23
    $185.23

    The Hayward Top/flue Cover- H150 is a genuine Hayward replacement part that forms part of the heater cabinet, providing protection and weather resi...

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    $185.23
    $185.23 - $247.51
    $185.23
    $185.23
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  • Hayward_Thermostat_Control_Board_-_50HZ_FD

    Hayward Thermostat Control Board - 50Hz

    $666.88
    $666.88
    $666.88
    $666.88

    The Hayward Thermostat Control Board - 50h is a genuine Hayward replacement part that monitors and regulates water temperature for accurate heating...

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    $666.88
    $666.88
    $666.88
    $666.88
  • Hayward_Gas_Heater_Thermistor

    Hayward Thermistor

    $147.62
    $147.62
    $147.62
    $147.62

    The Hayward Thermistor is a genuine Hayward replacement part that monitors and regulates water temperature for accurate heating control. Designed s...

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    $147.62
    $147.62
    $147.62
    $147.62
  • Hayward H150 Wiring Harness 50Hz H150 - Gas Heater Spare Part

    Hayward Terminal Block - 5 Pole

    $70.07
    $70.07
    $70.07
    $70.07

    The Hayward Terminal Block- 5 Pole is a genuine Hayward replacement part that is an essential component for correct heater operation. Designed spec...

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    $70.07
    $70.07
    $70.07
    $70.07
  • Hayward_Gas_Heater_Rightside_Trim_Panel_-_FD

    Hayward Right Trim Panel

    $191.54
    $191.54
    $191.54
    $191.54

    The Hayward Right Trim Panel - is a genuine Hayward replacement part that forms part of the heater cabinet, providing protection and weather resis...

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    $191.54
    $191.54
    $191.54
    $191.54
  • Hayward_Gas_Heater_Right_Junction_Box_-_FD

    Hayward Right Junction Box

    $133.96
    $133.96
    $133.96
    $133.96

    The Hayward Right Junctionbox - is a genuine Hayward replacement part that is an essential component for correct heater operation. Designed specif...

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    $133.96
    $133.96
    $133.96
    $133.96
  • _Hayward_Gas_Heater_Rear_Access_Door_Assembly

    Hayward Rear Access Door Assembly

    $280.27
    $280.27 - $326.98
    $280.27
    $280.27

    The Hayward Rear Access Door Asm - H150 is a genuine Hayward replacement part that forms part of the heater cabinet, providing protection and weath...

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    $280.27
    $280.27 - $326.98
    $280.27
    $280.27
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  • _Hayward_Gas_Heater_Rain_Guard_Assembly

    Hayward Rain Guard Assembly

    $448.45
    $448.45
    $448.45
    $448.45

    The Hayward Rain Guard Asm-h150 is a genuine Hayward replacement part that forms part of the heater cabinet, providing protection and weather resis...

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    $448.45
    $448.45
    $448.45
    $448.45
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  • _Hayward_Gas_Heater_One_Screw_Front_Access_Door

    Hayward One Screw Front Access Door

    $386.17
    $386.17 - $454.62
    $386.17
    $386.17

    The Hayward One Scw Frt Access Door H150 is a genuine Hayward replacement part that forms part of the heater cabinet, providing protection and weat...

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    $386.17
    $386.17 - $454.62
    $386.17
    $386.17
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  • Hayward_Manual_Reset_Limit_-_H150-400FDAU

    Hayward Manual Reset Limit

    $239.72
    $239.72
    $239.72
    $239.72

    The Hayward Manual Reset Limit - H150/400 is a genuine Hayward replacement part that provides a safety cutoff to prevent overheating damage. Design...

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    $239.72
    $239.72
    $239.72
    $239.72
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  • Hayward_Gas_Heater_Leftside_Lower_Panel_-_FD

    Hayward Lower End Cap

    $216.37
    $216.37
    $216.37
    $216.37

    The Hayward Lower End Cap - is a genuine Hayward replacement part that is an essential component for correct heater operation. Designed specifical...

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    $216.37
    $216.37
    $216.37
    $216.37
  • Hayward_Gas_Heater_Leftside_Trim_Panel_-_FD

    Hayward Left Trim Panel

    $199.33
    $199.33
    $199.33
    $199.33

    The Hayward Left Trim Panel - is a genuine Hayward replacement part that forms part of the heater cabinet, providing protection and weather resist...

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    $199.33
    $199.33
    $199.33
    $199.33
  • Hayward_Gas_Heater_Left_Junction_Box_-_FD

    Hayward Left Junction Box

    $143.22
    $143.22
    $143.22
    $143.22

    The Hayward Left Junction Box - is a genuine Hayward replacement part that connects and routes electrical power between heater components. Designe...

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    $143.22
    $143.22
    $143.22
    $143.22
  • _Hayward_Gas_Heater_Jacket_Top_Flue_Cover_bc2e318e

    Hayward Jacket Top & Flue Cover

    $406.44
    $406.44 - $490.46
    $406.44
    $406.44

    The Hayward Jacket Top & Flue Cover H150 is a genuine Hayward replacement part that forms part of the heater cabinet, providing protection and ...

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    $406.44
    $406.44 - $490.46
    $406.44
    $406.44
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  • Hayward H150 Wiring Harness 50Hz H150 - Gas Heater Spare Part

    Hayward Igniter Access Cover

    $59.20
    $59.20
    $59.20
    $59.20

    The Hayward Igniter Acces Cover is a genuine Hayward replacement part that ignites the gas burner to start your pool heater. Designed specifically ...

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    $59.20
    $59.20
    $59.20
    $59.20
  • Hayward_Gas_Heater_Manual_Reset_Limit_-_H150-400FDAU

    Hayward High Limit 135F

    $165.10
    $165.10
    $165.10
    $165.10

    The Hayward High Limit 135f is a genuine Hayward replacement part that provides a safety cutoff to prevent overheating damage. Designed specificall...

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    $165.10
    $165.10
    $165.10
    $165.10
  • AstralPool IXI IXI 200 IXI 370 Fuel Orifice Kit, To Convert A Natural To A Propane - Heater Spare Part

    Hayward Heater Kit - Control Bezel Lock

    $287.39
    $287.39
    $287.39
    $287.39

    The Hayward Heater Kit -control Bezel Lock is a genuine Hayward replacement part that forms part of the heater cabinet, providing protection and we...

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    $287.39
    $287.39
    $287.39
    $287.39
  • Hayward_Gas_Heater_Heat_Exchanger_Assembly

    Hayward Heat Exchanger Assembly

    $3,248.02
    $3,248.02 - $4,160.65
    $3,248.02
    $3,248.02

    The Hayward Heat Exchanger - H150 H250 H400 is a genuine Hayward replacement part that transfers heat from the burner to the pool water. Designed s...

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    $3,248.02
    $3,248.02 - $4,160.65
    $3,248.02
    $3,248.02
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  • Hayward_Gas_Heater_Heat_Barrier_Panel

    Hayward Heat Barrier Panel

    $185.23
    $185.23 - $228.85
    $185.23
    $185.23

    The Hayward Heat Barrier Panel - H150 is a genuine Hayward replacement part that forms part of the heater cabinet, providing protection and weather...

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    $185.23
    $185.23 - $228.85
    $185.23
    $185.23
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  • Hayward_Gas_Heater_Header_O-Ring_Kit

    Hayward Header O-Ring Kit

    $76.09
    $76.09
    $76.09
    $76.09

    The Hayward Header O-ring Kit is a genuine Hayward replacement part that provides a watertight or airtight seal between heater components. Designed...

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    $76.09
    $76.09
    $76.09
    $76.09
  • Hayward_Gas_Heater_Header_Hardware_Kit

    Hayward Header Hardware Kit

    $99.59
    $99.59
    $99.59
    $99.59

    The Hayward Header Hardware Kit is a genuine Hayward replacement part that connects water inlet and outlet to the heat exchanger. Designed specific...

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    $99.59
    $99.59
    $99.59
    $99.59
  • Hayward_Gas_Heater_Header_Assembly_Kit

    Hayward Header Assembly

    $699.96
    $699.96
    $699.96
    $699.96

    The Hayward Header Assembly is a genuine Hayward replacement part that connects water inlet and outlet to the heat exchanger. Designed specificall...

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    $699.96
    $699.96
    $699.96
    $699.96
  • Hayward H150 Wiring Harness 50Hz H150 - Gas Heater Spare Part

    Hayward Hardware Mounting Base Kit

    $68.45
    $68.45
    $68.45
    $68.45

    The Hayward Hardware Mounting Base Kit is a genuine Hayward replacement part that is an essential component for correct heater operation. Designed ...

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    $68.45
    $68.45
    $68.45
    $68.45
  • Hayward H150 Wiring Harness 50Hz H150 - Gas Heater Spare Part

    Hayward Gasket Kit - Exhaust Side All

    $355.03
    $355.03
    $355.03
    $355.03

    The Hayward Gasket Kit - Exhaust Side All is a genuine Hayward replacement part that provides a watertight or airtight seal between heater componen...

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    $355.03
    $355.03
    $355.03
    $355.03
  • Hayward H150 Wiring Harness 50Hz H150 - Gas Heater Spare Part

    Hayward Gasket Kit - Air Side

    $186.84
    $186.84
    $186.84
    $186.84

    The Hayward Gasket Kit - Air Side is a genuine Hayward replacement part that provides a watertight or airtight seal between heater components. Des...

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    $186.84
    $186.84
    $186.84
    $186.84
  • Hayward_GAS_VALVE

    Hayward Gas Valve Natural

    $750.61
    $750.61
    $750.61
    $750.61

    The Hayward Gas Valve Natural - is a genuine Hayward replacement part that controls the flow of gas to the burner assembly. Designed specifically ...

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    $750.61
    $750.61
    $750.61
    $750.61
  • Hayward_Gas_Manifold_-_H150-400FD

    Hayward Gas Manifold

    $174.36
    $174.36 - $191.54
    $174.36
    $174.36

    The Hayward Gas Manifold -H150 H250 H400 is a genuine Hayward replacement part that distributes gas evenly across the burner assembly. Designed spe...

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    $174.36
    $174.36 - $191.54
    $174.36
    $174.36
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  • AstralPool IXI IXI 200 IXI 370 Fuel Orifice Kit, To Convert A Natural To A Propane - Heater Spare Part

    Hayward Gas Heater Thermostat Control Board – 50Hz

    $561.00
    $561.00
    $561.00
    $561.00

    Hayward Thermostat Control Board – 50Hz — OEM thermostat PCB for FD heaters. Maintains setpoint logic and coordinates sensor/ignition inputs. Fun...

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    $561.00
    $561.00
    $561.00
    $561.00
  • AstralPool IXI IXI 200 IXI 370 Fuel Orifice Kit, To Convert A Natural To A Propane - Heater Spare Part

    Hayward Gas Heater Thermostat Board Bezel & Keypad Assembly

    $225.50
    $225.50
    $225.50
    $225.50

    Hayward Thermostat Board Bezel & Keypad Assembly — OEM fascia surround and touchpad label for Hayward FD control panels. Refreshes the interfac...

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    $225.50
    $225.50
    $225.50
    $225.50
  • AstralPool IXI IXI 200 IXI 370 Fuel Orifice Kit, To Convert A Natural To A Propane - Heater Spare Part

    Hayward Gas Heater Manual Reset Hi-Limit

    $224.60
    $224.60
    $224.60
    $224.60

    Hayward Manual Reset Limit — Safety cut-out for Hayward FD heaters requiring manual reset after an over-temp condition, ensuring safe fault recover...

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    $224.60
    $224.60
    $224.60
    $224.60