H1657 SIT NG Millivolt Valve NG fireplace replacement part

H1657 SIT MILLIVOLT VALVE – Natural Gas – Millivolt

$267.00
$267.00
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H1657 SIT NG Millivolt Valve NG fireplace replacement part
  • H1657 SIT NG Millivolt Valve NG fireplace replacement part
  • H1657 SIT NG Millivolt Valve NG fireplace replacement part
  • H1657 SIT NG Millivolt Valve NG fireplace replacement part
  • H1657 SIT NG Millivolt Valve NG fireplace replacement part
  • H1657 SIT NG Millivolt Valve NG fireplace replacement part
  • H1657 SIT NG Millivolt Valve NG fireplace replacement part
H1657 SIT MILLIVOLT VALVE – Natural Gas – Millivolt

H1657 SIT MILLIVOLT VALVE – Natural Gas – Millivolt

$267.00
$267.00
1 left

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The H1657 gas valve is a Natural Gas millivolt (standing pilot) control valve responsible for regulating gas flow to the pilot and main burner.
In a millivolt system, the valve is operated by low voltage generated by the pilot assembly thermopile and allows gas flow only when the safety circuit is properly established.

Not sure if this is the right part?

Before ordering, check the following:

  • Locate your model number (typically behind the lower louver or inside the control compartment)
  • Confirm your unit uses a millivolt (standing pilot) system
  • Confirm your gas type is natural gas
  • Compare your existing valve to the images provided

⚠️ This part is NOT for IPI (electronic ignition) systems
⚠️ This part is NOT for propane (LP) units

If unsure, refer to your manual or contact us for help identifying the correct part.

🔁 Using propane (LP) instead of natural gas?
This part will not work. View the correct LP version here: 88J53

Compatible Models

Earth Stove Gas Stoves:
BayFire DVI
BayFire FS Europa
BayFire L
BayFire XL
GBV40
GBV40DV
GL25DV
TG25DV

Ironstrike Gas Inserts:
CI1508DVF2
CI2508DVF2

Ironstrike Gas Stoves:
CI1500DVF
CI1502DVF
CI1504DVF
CI1506DVF
CI2500DVF
CI2502DVF
CI2504DVF
CI2506DVF

Lennox Gas Fireplaces:
EBVI25
EDVI25
LMDV3530CNM
LMDV4035CNM
LMDVR3328CNM
LMDVT3328CNM
MPD3530CNM
MPD3530CNMB
MPD4035CNM
MPD4035CNMB
MPD4540CNM
MPD4540CNMB
MPDR3328CNM
MPDT3328CNM

Lennox Gas Stoves:
L20BF
L20DHF
L20DVF
L30BF
L30BI
L30DHF
L30DVF
TG300DV

Whitfield Gas Inserts:
Vision30InsertV3B1

Whitfield Gas Stoves:
ReflectionsIIWG2II
Vision20V2BF
Vision20V2DHF
Vision20V2DVF
Vision30V3BF
Vision30V3DHF
Vision30V3DVF

System Type

This is a millivolt standing pilot system. These systems use a continuously burning pilot flame and do not require household electrical power for basic operation.

Millivolt systems are commonly found in many direct vent gas fireplaces and are known for simple, reliable operation.

This system commonly includes:

  • Thermocouple — helps keep the pilot gas valve open when the pilot flame is proven.
  • Thermopile — generates millivolt power used to operate the main gas valve.
  • Igniter electrode — provides manual spark ignition, usually from a push-button piezo igniter.
  • Pilot tube — delivers gas from the valve to the pilot assembly.

Because these systems do not rely on external power, they can often operate during a power outage when used with a manual switch or compatible battery-free control setup.

These systems offer improved efficiency, remote-control compatibility, and added safety features, but they also include more electronic components than a millivolt system.

Common Problems This Valve Fixes

If your fireplace uses a millivolt (standing pilot) system, the gas valve is the control center. When it begins to fail, it can cause a range of frustrating and sometimes confusing issues.

Replacing the valve often resolves the following problems:

  • Pilot stays lit but burner will not turn on
    The valve is not opening when it receives voltage from the thermopile.
  • Fireplace turns on intermittently or unpredictably
    Internal valve components can wear out, causing inconsistent operation.
  • No response from wall switch or remote
    Even with a good thermopile, a faulty valve may not react to the signal.
  • Burner shuts off unexpectedly
    The valve may be failing internally and dropping out under load.
  • Weak or unstable burner flame
    Improper gas regulation inside the valve can affect flame performance.
  • Gas flow issues, low flame, or no flame
    A failing valve can restrict or inconsistently supply gas to the burner.
  • Clicking or switching sounds but no burner ignition
    The system is calling for heat, but the valve is not opening.
  • Valve knob feels loose, stuck, or does not function properly
    Mechanical wear or internal damage to the valve body may prevent proper operation.

Important Note

Many of these symptoms can also be caused by a weak thermopile, thermocouple failure, dirty pilot assembly, switch wiring issues, or improper gas pressure. Proper diagnosis is strongly recommended before replacing the valve.

Warranty Information

This product includes a 12-month warranty from the date of purchase. This warranty covers defects in materials or workmanship under normal operating conditions.

Fireplace components must be properly installed and matched to the correct system (millivolt vs IPI, natural gas vs propane).

This warranty does NOT cover:
• Improper installation or incorrect application
• Use with the wrong gas type (NG vs LP)
• Misdiagnosis of the issue
• Damage caused by other failing components
• Normal wear and tear
• Labor, service, or diagnostic time

Because many fireplace issues can be caused by multiple components, we strongly recommend confirming the diagnosis before replacing parts.

We are happy to assist with this. Proof of purchase is required for all warranty claims. Please contact us prior to removal or replacement of the part so we can help verify the issue and guide the warranty process.

How do I know if my valve is bad?

Common signs of a failing gas valve include the pilot staying lit but the burner not turning on, no response from a wall switch or remote, intermittent operation, or the burner shutting off unexpectedly.

In some cases, the valve may fail to open and allow gas to flow, even though the system is calling for heat. You may also notice inconsistent flame behavior or complete loss of burner function.

Before replacing the valve, it is important to verify that other components such as the thermopile, thermocouple, ignition module, or wiring are functioning properly, as these can cause similar symptoms.

How difficult is this part to replace?

Replacing a gas valve is considered a moderate to advanced repair because it involves working with gas lines and critical safety components.

The process typically requires shutting off the gas supply, disconnecting and reconnecting fittings, and ensuring all connections are properly sealed and leak-free. In many cases, adjustments or system checks are also needed after installation.

For safety and proper operation, installation is recommended to be performed by a qualified technician.

Is this a safe DIY repair?

Gas valve replacement involves working with gas lines and safety-critical components, so it is generally not recommended as a DIY repair for most homeowners.

Improper installation can result in gas leaks, unsafe operation, or damage to the fireplace system. Correct procedures, proper tools, and leak testing are essential to ensure safe operation.

For safety and reliability, installation is recommended to be performed by a qualified technician.

Do I need any special tools to install this?

Gas valve replacement typically requires standard hand tools such as wrenches and screwdrivers, along with gas-rated thread sealant or tape for proper sealing of fittings.

A manometer may also be needed to verify proper gas pressure after installation, and leak detection solution is required to ensure all connections are safe and secure.

Because proper setup and testing are critical for safe operation, installation is recommended to be performed by a qualified technician.