Robertshaw Millivolt Gas Valve Magnet - Unitrol Flame Failure Power Unit (RBS83399)
Robertshaw Millivolt Gas Valve Magnet - Unitrol Flame Failure Power Unit (RBS83399)
Description
This is a Robertshaw millivolt gas valve magnet (part RBS83399) - the flame-failure power unit for Robertshaw Unitrol gas valves. It is designed for a millivolt (thermopile) system, where a thermopile generates a higher voltage (around 750 millivolts) that both holds the magnet in and powers the valve, with no external electrical supply. If the flame fails, the magnet releases and shuts off the gas supply.
This is the millivolt version and is not interchangeable with the thermocouple version - fitting the wrong type will stop the valve holding open.
Technical Specifications
| Specification | Detail |
|---|---|
| Brand | Robertshaw |
| Type | Millivolt gas valve magnet (flame-failure power unit) |
| Manufacturer Part Number (MPN) | RBS83399 |
| System | Millivolt operated |
| Fits | Robertshaw Unitrol gas valves |
| Function | Holds the gas valve open while the pilot is lit; releases to shut off gas on flame failure |
| Condition | New |
Fitment
Fits Robertshaw Unitrol gas valves running a millivolt flame-failure system. This part is not for use on standard thermocouple valves - use RBS83397 for those. If in doubt, contact us with your valve make, model and existing part number and we will confirm compatibility before you order.
Gas Safety
Signs You Need To Replace This Part
- The pilot or burner lights while the control knob is held in, but drops out when released
- The valve will not hold open even with a known-good thermopile
- Intermittent flame-failure shut-off during normal operation
What Is Included
- 1 x Robertshaw millivolt gas valve magnet (RBS83399)
Thermocouple, thermopile and gas valve are not included.
Frequently Asked Questions
Will this magnet fit my Robertshaw Unitrol gas valve?
It fits Robertshaw Unitrol gas valves that use a millivolt flame-failure system. Confirm your valve is the millivolt type before ordering, as the millivolt and the other version are not interchangeable.
What is the difference between the thermocouple and millivolt magnet?
The thermocouple magnet (RBS83397) is for standard thermocouple systems, and the millivolt magnet (RBS83399) is for millivolt / thermopile systems, which run at a higher voltage. They have different coils and must not be swapped for one another.
What does the gas valve magnet do?
It is the electromagnet inside the valve. Held energised by a millivolt (thermopile) system, where a thermopile generates a higher voltage (around 750 millivolts) that both holds the magnet in and powers the valve, with no external electrical supply. If the flame goes out, the power falls away, the magnet releases and the gas is shut off - the flame-failure safety function.
How do I know mine has failed?
A common sign is a pilot or burner that lights while you hold the control knob in, but goes out as soon as you release it, once the thermocouple / thermopile and its connections have been checked.
Who should fit this part?
A Gas Safe registered engineer. It is a gas safety component and must be installed and tested by a qualified engineer.
Why LaunchCatering
Stocked in the UK and matched by specification. We identify the exact power unit type so you can confirm it against your valve before you order. A trusted supplier of commercial catering gas spares.
No technical specifications available for this product.
