SRV14D0473 MILLIVOLT ODS PILOT ASSEMBLY – Natural Gas – Millivolt ODS
SRV14D0473 MILLIVOLT ODS PILOT ASSEMBLY – Natural Gas – Millivolt ODS
⚠ Special order — Ships in 1–2 weeks
What This Part Does
This ODS pilot assembly provides the standing pilot flame used to safely operate a vent-free gas fireplace, gas stove, or gas log set.
The pilot flame heats the thermocouple and, on many systems, the thermopile. The thermocouple helps keep the pilot safety circuit open, while the thermopile generates millivoltage used by the wall switch, thermostat, remote receiver, or main burner circuit.
The ODS portion of the pilot assembly monitors the air/fuel mixture through a precision pilot air intake. If oxygen levels become too low, or if the pilot flame becomes unstable, the flame will move away from the thermocouple and the gas valve will shut down for safety.
A restricted or failing ODS pilot assembly can cause nuisance shutdowns, weak pilot flame, failure to stay lit, or failure of the main burner to ignite.
ODS pilot assemblies are appliance-specific and must be matched to the correct model, gas type, and manufacturer part number.
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 ODS system
- Confirm your gas type is natural gas
- Compare your existing pilot assembly to the images provided
⚠️ This part is NOT for standard millivolt, IPI, or non-ODS pilot systems
⚠️ This part is NOT for propane (LP) units
Compatible Models
Majestic Gas Log Sets:
24VL
30VL
Monessen Gas Fireplaces:
32VFH
32VFHC
32VFSC
33ISDG
33ISDVL
36VFH
36VFHC
42VFH
42VFHC
DFC32
DFC36
DFC42
DFS3224
DFS3224A
DFS32A
DFS36
DFS36A
DFS36C
DFS42
DFS42C
DFX32
DIS33
DIS33C
DIS33D
DIS33G
DZC36
DZS36
MCFS36
Monessen Gas Log Sets:
18HVFL
18NB
18TPB
18VL
18VLS
24NB
24TPB
24VFS
24VFSC
24VLS
30TPB
C28VF
CSVF20S
CSVF30S
DCS
DEB24
DEB30
DFX24C
DL18MILLIVOLT
DL2428MILLIVOLT
DLX18BMILLIVOLT
DLX18MILLIVOLT
DLX2428BMILLIVOLT
DLX2428MILLIVOLT
DLY18
DNF18
DNF24
DSS
DST30
DYD18
DYD24
DYS18
DYS24
EYF18
GG18NIF
GG18NV
HVFL18
MJ27NIF
MJ27R
NB18
NB24
TPB18
TPB30
VFCS20D
VFCS30D
Monessen Gas Stoves:
AVFL42NTSC
AVFL42PTSC
CFX24
CSVF20SNV
CSVF30SNV
DFS36NVC
DFS36PVC
SS28VF
VFCS20DNV
VFCS30DNV
VFSS
System Type
This is a millivolt ODS standing pilot system. These systems are commonly used on vent-free gas fireplaces, vent-free gas stoves, and vent-free gas log sets.
The system uses a continuously burning pilot flame to heat the thermocouple and, on many models, a thermopile. The thermocouple proves the pilot flame and keeps the pilot safety circuit open. The thermopile generates millivoltage used to operate the main burner through a wall switch, thermostat, or remote receiver.
This system commonly includes:
- ODS pilot assembly — monitors the pilot flame and oxygen-sensitive air mixture for safe operation.
- Thermocouple — keeps the pilot gas valve open when the pilot flame is proven.
- Thermopile — generates millivoltage to operate the main burner circuit.
- Millivolt gas valve — controls pilot and burner gas flow.
- Piezo igniter or electrode — provides manual spark ignition for lighting the pilot.
The ODS pilot is designed to shut the appliance down if the pilot flame becomes unstable or if oxygen levels fall below the appliance’s safety threshold.
Because ODS systems depend on a precise pilot air intake, dust, lint, pet hair, or spider webs can cause a weak pilot flame, nuisance shutdowns, or failure of the pilot to stay lit.
Common Problems This ODS Pilot Assembly May Fix
- Pilot will not stay lit after releasing the control knob
- Pilot flame is weak, lazy, lifting, or unstable
- Pilot lights but goes out after a few minutes
- Main burner will not light because the pilot flame is not heating the thermocouple or thermopile properly
- Fireplace or log set shuts down unexpectedly during operation
- ODS safety shutdown caused by dust, lint, pet hair, or debris in the pilot air intake
- Intermittent pilot outage on vent-free fireplaces, stoves, or log sets
- Pilot assembly failure or restricted ODS pilot
An ODS pilot assembly is used on many vent-free gas fireplaces, gas stoves, and gas log sets. The ODS, or Oxygen Depletion Sensor, is built into the pilot assembly and is designed to shut the appliance down if the pilot flame becomes unsafe or if room oxygen levels fall below the appliance’s safety threshold.
Because the ODS pilot depends on a precise air intake, even a small amount of dust, lint, pet hair, or spider web blockage can cause a weak or unstable pilot flame. This may prevent the thermocouple or thermopile from staying hot enough to keep the gas valve open.
Before replacing the ODS pilot assembly, inspect and clean the pilot air intake according to the appliance manual. Also confirm proper gas supply, correct pilot flame contact, and proper log placement, since these issues can cause similar symptoms.
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.
Do I need any special tools to install this?
Most pilot assemblies can be installed using basic hand tools, and no specialized equipment is typically required.
In most cases, you will need:
• Adjustable wrench or open-end wrenches
• Screwdrivers (Phillips and/or flathead)
• Nut driver or socket set
The pilot assembly is usually mounted near the burner and connected by a pilot tube and thermocouple or thermopile. Installation involves removing the old assembly, reconnecting the gas line components, and securing the new pilot in place.
It is important to ensure all connections are tight and properly aligned. After installation, always check for gas leaks using a leak detection solution and confirm proper pilot flame appearance.
If you are unsure or uncomfortable working with gas components, we recommend having a qualified technician perform the installation to ensure safe and proper operation.
Do I need to make any adjustments after installation?
In most cases, no major adjustments are required after installing a pilot assembly, but a few important checks should always be performed to ensure proper operation.
After installation, you should:
• Verify the pilot flame is steady and properly positioned over the thermocouple or flame sensor
• Confirm the flame is strong enough to fully engulf the sensor (not weak or lifting)
• Check all gas connections for leaks using a leak detection solution
Some systems may include a pilot adjustment screw on the gas valve. If needed, this can be used to fine-tune the pilot flame height, but many modern systems are preset and do not require adjustment.
If the pilot flame appears weak, unstable, or does not stay lit, this may indicate an issue with gas pressure, air in the line, or another component in the system.
Proper flame appearance and stable operation are key to safe and reliable performance. If you are unsure about flame characteristics or adjustments, we recommend consulting a qualified technician.
How difficult is this part to replace?
Replacing a pilot assembly is generally considered a moderate repair and can often be completed by a homeowner with basic mechanical skills.
The process typically involves accessing the burner area, disconnecting the pilot tube and sensor leads, removing the old assembly, and installing the new one in the same position.
While no specialized tools are usually required, the work does involve gas connections and components that must be installed correctly to ensure safe operation.
For someone comfortable working with hand tools and following instructions carefully, this is a manageable repair. However, access to the pilot assembly can vary depending on the fireplace model, and some units may require additional disassembly.
If you are unsure about working with gas systems or identifying proper flame characteristics after installation, we recommend having a qualified technician perform the replacement.
How do I know if my pilot assembly is bad?
A bad pilot assembly will usually show clear symptoms related to ignition problems or unstable flame performance.
Common signs of a faulty pilot assembly include:
• Pilot will not light at all
• Pilot lights but will not stay lit
• Weak, small, or flickering pilot flame
• Pilot lights but the main burner does not turn on
• Intermittent operation or frequent shutdowns
In many cases, the issue is caused by a worn or failing thermocouple or thermopile, a clogged pilot hood, or a damaged ignition component. Dirt, dust, or corrosion can also affect how the pilot flame contacts the sensor.
A proper pilot flame should be steady, strong, and fully engulf the thermocouple or flame sensor. If the flame is weak, not making good contact, or going out unexpectedly, the pilot assembly may need to be cleaned or replaced.
Before replacing the assembly, it is also important to rule out other possible causes such as low gas pressure, air in the gas line, or a faulty gas valve.
If cleaning does not resolve the issue or the components show signs of wear or damage, replacing the pilot assembly is often the most reliable solution.