37D0019K SIT PILOT ASSEMBLY – Propane – Millivolt
37D0019K SIT PILOT ASSEMBLY – Propane – Millivolt
✔ In stock — Usually ships in 1–2 business days
What This Part Does
The 37D0019K pilot assembly is a Propane LP millivolt (standing pilot) ignition component responsible for lighting the pilot flame and generating the electrical signal required to operate the gas valve.
In a millivolt (standing pilot) system, the pilot flame heats the thermocouple and thermopile. The thermocouple helps keep the pilot gas flow open for safety, while the thermopile generates the millivolt power used to operate the main gas valve.
When a call for heat is made from a wall switch, thermostat, or remote, the thermopile supplies voltage to the gas valve, allowing it to open and deliver gas to the main burner.
This assembly also includes the pilot burner and ignition source, which are responsible for reliably lighting the pilot flame.
Proper pilot assembly operation is essential for safe ignition, consistent voltage generation, and reliable fireplace performance.
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 propane (LP)
- Compare your existing pilot assembly to the images provided
⚠️ This part is NOT for IPI (electronic ignition) systems
⚠️ This part is NOT for natural gas (NG) units
If unsure, refer to your manual or contact us for help identifying the correct part.
🔁 Using natural gas (NG) instead of propane (LP)?
This part will not work. View the correct NG version here: 37D0018K
Compatible Models
Majestic Gas Fireplaces:
300DVB
300DVB_7
300DVBC
300DVBH
300DVBH_7
300DVBNPV7
300DVBNSCSL
300DVBNVSL
300DVBPSCSL
300DVBPVSL
30ILDV
30ILDVNVSB
30ILDVPVSB
33CFDVNISL
33CFDVNVSL
33CFDVPISL
33CFDVPVSL
36CDVXRRN
36CDVXTRN
36CDVZRRN
36CDVZTRN
400BBVA
400BBVNSC
400BBVNVA
400BBVPVA
400DVB
400DVB_7
400DVBC
400DVBH
400DVBH_7
400DVBL
400DVBL_7
400DVBMH_7
400DVBNSCSL
400DVBNVSL
400DVBPSCSL
400DVBPVSL
400SBVNSC
400SBVNVA
400SBVPVA
40ILDV
490IDV
500DVB
500DVB_7
500DVBC
500DVBL
500DVBL_7
500DVBNSCSL
500DVBNVSL
500DVBPSCSL
500DVBPVSL
500DVM
500DVML
500DVS
500SBVNSC
500SBVNVA
500SBVPVA
600DVB
600DVB_7
600DVBC
600DVM
600DVS
BDV300C
BDV400C
BDV500C
BDV600C
CSDV20DC
CSDV20SC
CSDV30DC
CSDV30SC
CSDV30SNVEMBSL
CSDV30SNVGSL
CSDV30SPVEMBSL
CSDV30SPVGSL
GBVC36
GBVC42
GBVR36
GBVR42
GDVR36
GDVR42
GDVT36
GDVT42
LX32DVNSL
LX32DVPSL
LX36DVNSL
LX36DVPSL
Monessen Gas Fireplaces:
1000 SERIES 116DV3732
1000 SERIES 116DV4136
2000 SERIES 216DV3732
2000 SERIES 216DV4136
2000 SERIES 216DV4742
3000 SERIES 320DV4136
3000 SERIES 320DV4742
36CDV
36CDVXR
36CDVXT
36CDVZR
36CDVZT
36CFDV
BBV400A
BDV300
BDV300_7
BDV400
BDV400_7
BDV500
BDV500_7
BDV600
BDV600_7
BLDV400
BLDV400_7
BLDV500
BLDV500_7
CDVR33
CDVR33(7) (T-Lock)
CDVR36
CDVR36 CDVT36(7) (T-Lock)
CDVR36_7
CDVR42 CDVT42(7) (T-Lock)
CDVR42_7
CDVR47 (T-Lock)
CDVR47_7
CDVT33
CDVT33(7) (T-Lock)
CDVT36
CDVT36_7
CDVT42_7
CDVT47(7) (T-Lock)
CDVT47_7
HBDV300
HBDV300_7
IDV380C
IDV490C
ILDV20
ILDV30
ILDV40
MDV500
MDV600
ML500DVPNSC
ML500DVPPSC
Temco Gas Fireplaces
VCG Gas Fireplaces:
LX32DVP
Vermont Castings Gas Fireplaces:
33CFDV
36CFDVNISL
36CFDVNVSL
36CFDVPISL
36CFDVPVSL
380IDV
380IDVNVSB
380IDVPVSB
42CFDV
42CFDVNISL
42CFDVNVSL
42CFDVPISL
42CFDVPVSL
500DVSC
600DVSC
AI31DVC
C28DV
C40DV
SBV500A
SDV500
SDV500C
SDV600
SDV600C
SS38DV
VS38DV
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 Part Fixes
If your fireplace uses a millivolt (standing pilot) system, the pilot assembly is responsible for generating the voltage needed to operate the gas valve and proving flame safety. When it begins to fail, it can cause a range of ignition and operating issues.
Replacing the pilot assembly often resolves the following problems:
- Pilot will not stay lit
A weak or failing thermocouple may not keep the gas valve open. - Pilot lights but goes out when the knob is released
The thermocouple is not properly generating or delivering a safety signal. - Pilot flame is weak, small, or unstable
A clogged pilot orifice or worn components can affect flame quality. - Burner will not turn on even though pilot is lit
A weak thermopile may not generate enough voltage to operate the valve. - Intermittent operation or delayed burner ignition
Inconsistent voltage output from the pilot assembly can cause unreliable performance. - No response from wall switch or remote
Insufficient millivolt output can prevent the system from activating. - Difficulty lighting the pilot
A worn igniter electrode or misaligned pilot components can prevent proper ignition.
Important Note
Many of these symptoms can also be caused by a faulty gas valve, loose wiring, or improper gas pressure. Proper diagnosis is recommended before replacing the pilot assembly.
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.