Where should the main burner of a gas-fired boiler have an approved manual shut-off valve installed?

The main burner of a gas-fired boiler should have an approved manual shut-off valve installed downstream of all control devices. This placement is crucial for safety and operational efficiency.

When the valve is located downstream of control devices, it allows for the safe operation and maintenance of the control systems, such as safety shut-off valves and flame sensors. This configuration ensures that, in the event of a malfunction or during maintenance, the gas supply can be completely shut off while still allowing the control devices to function properly.

Additionally, positioning the valve in this manner prevents the risk of gas leaking into the areas where control devices are located, which could pose significant safety hazards. In contrast, having the valve located before all control devices could create a dangerous situation where the gas is still supplied to potentially faulty equipment.

This arrangement enhances both safety and compliance with regulations, ensuring that the entire system operates within the design parameters established for gas-fired boilers.