How to Replace a Steam Radiator Valve

What You'll Need
Replacement washers
Valve packing
Pliers needle nose

All hot water systems can have leaking problems and replacing a steam radiator valve is one of the least difficult problems to fix. Deterioration of the packing around stem or washer can lead to inlet valve leaks. The inlet valve is made up of a washer, valve stem or body and a packing nut. This tutorial will show you how to replace the washer or valve packing of an inlet valve. These can cause mess and noise if they are badly maintained and leaking. Luckily this is a cheap and easy problem to fix. 

Step 1 – Shut off the Boiler

You don’t need to shut off the water supply as water will flow out as it cools, back into the boiler. Allow to cool. 

Step 2 – Remove the Handle Assembly

To replace the valve, you will be removing and replacing the gasket which is inside the packing nut. This gasket prevents steam from escaping and seals the valve connection.

Remove the handle by unscrewing the screw that holds it in place. Remove all the parts, which include valve stem, packing nut and handle. Turn the stem over and remove the screw and washer at the bottom. Affix a new washer of the same type and size. You may have to take it to a hardware store to be sure it is the right one.

If the packing nut is difficult to remove, you may have to use the wrench to loosen it and remove it from the stem. The rubber gasket should be easy to remove with a screwdriver or pliers. You may need to scrape it out if it is deteriorated. 

Step 3 – Reassemble the Valve

Reassemble the valve after installing new packing. The graphite valve packing is important. It looks like a piece of rubbery black string. You can find it in the plumbing department in a hardware store. Take the packing out of its packet and loop it around the stem 3 times, making sure you wind it around clockwise so you can thread the packing nut back over it. Don’t pull it tight or it will break.

Reattach the handle and turn the system back on, after tightening the connections. 

Step 4 – Maintain the System to Avoid Future Leaks 

There are other leakage problems that you might come across. Old and poorly maintained systems are prone to leaking and other problems so you should also learn how to drain and flush your hot water and steam system.

A leaking valve causes your heating system to be inefficient as the system can only work well when the steam stays inside it. The boiler kicks in every now and then when the pressure drops but if there is a leaky valve, the steam is allowed to escape and that means that the pressure drops more often, forcing the boiler to kick in a lot more often. This burns more oil or gas, burning a hole in your wallet.