How to Reset and Repair a Safety Relief Valve

Step 1

Shut the automatic fill valve.

Step 2

Check the pressure on the boiler to confirm that it is not pressurized above the the minimum operating pressure of the relief valve. The minimum operating pressure or relieving pressure of the relief valve is clearly stated on the information tag attached to the relief valve.

Step 3

If the boiler is over pressurized, the boiler pressure must be lowered to less than the minimum operating pressure of the relief. This can be accomplished by continuing to drain water from the boiler until the gauge reads the appropriate pressure.

Step 4

Lift and release the test lever to re-seat the valve.

Step 5

If Step 4 does not work, tap with moderate force on the side of the relief to free up possible debris or corrosion from the valve seat and repeat Step 2.

Step 6

If these steps do not work to re-seat the valve and the boiler is under the minimum operating pressure of the relief valve, the relief valve will need to be replaced.

References

• Watts Plumbing, Heating, and Water Quality Products
• Example of a boiler explosion
• Watts 174A Boiler Pressure Relief Spec

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Tips

It is possible for an automatic fill that is set to the wrong pressure or is failing to cause a relief valve to "dump" or relieve pressure.

Any failure of the relief valve should signal the boiler operator to replace the relief valve at the earliest possible convenience, as these are critical safety devices.

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