The pressure relief valve on your boiler is a vital safety feature. Should excessive pressure build inside the boiler, for whatever reason, the pressure will trigger the valve to release water. The released water goes down a short drain pipe toward a floor drain or bucket. If you see this pipe start to drip, you need to find out how to change the pressure relief valve on a boiler. These valves tend to wear out over time due to constant pressure.
Tools You Need
- Pipe wrenches
- A Blow torch
- Oven mitt
- Garden hose or bucket
- A Screwdriver
- Boiler Parts You Need to Know
How to change the pressure relief valve on a boiler requires you to know some of the controls on the boiler. Before starting the job, make sure you can find the:
- Power shut off – The boiler should have its own circuit.
- Water supply valve
- Drain valve
- Pressure gauge
- Air vent
How to Change Pressure Relief Valve on Boiler
- Turn off the power supply to the boiler.
- Turn the valve handle to the off position on the water supply line.
- Give the boiler some time to cool down.
- Locate the drain valve. It may be threaded to receive a garden hose. If it is, attach a garden hose and direct the hose outside or to a drain. If you can’t connect a hose, get a bucket or pan to collect water.
- Open the drain valve and let the water out of the boiler.
- Watch the boiler’s pressure gauge. Once it reads zero pressure, you can proceed with removing the failing pressure relief valve.
- Take off the elbow connecting to the pipe leading down from the relief valve. If the pipe is soldered, heat up the joint with a blow torch. This will melt the solder, and you can pull the pipe free. Protect your hand with an oven mitt because the pipe could be hot.
- Now you can unscrew the old pressure relief valve with a pipe wrench.
- Wrap the top threads of your new valve with Teflon plumber’s tape.
- Screw the valve into place.
- Tighten with a pipe wrench.
- Wrap the threads on the elbow and tighten it onto the valve.
- Reconnect or solder the drain pipe as it was before.
- Turn the water supply valve back on.
- As the boiler fills with water, vent air that got into the system with the boiler’s air vent. You may need a screwdriver to operate the vent.
- You may also need to bleed air out at your radiators throughout the house.
- Restore power to the boiler and watch the pressure rise to normal.
- Monitor the new valve to make sure that it is not leaking.
Boiler Repair and Installation
Boilers are precision machines that require properly sealed pipe joints. If you prefer to hand off the pressure relief valve job to the professionals, talk to the team at Oliver. We are licensed plumbing and heating specialists based in Pennsylvania. Ask us for a boiler repair estimate today.