5 Steps to Healthy Steam Radiators

Posted on Posted in Repair Tips

5 Steps to Healthy Steam Radiators

A simple health checklist for your steam radiator from air valve to supply valve

steam radiators

The simple anatomy of a radiator

* This is actually a reprint of an article I wrote back in 2012. Not much has changed so I include it verbatim in its entirety here. If you'd like to see the full issue, click here!

      Every year, at about this time, we receive many calls about the steam radiators acting strangely.  Residents hear loud banging in their heating pipes, feel too much or no heat at all.  In many cases, we receive calls about water leaking from the supply valves or the air valves.  Sometimes, a defective radiator can even release large amounts of steam into the surrounding air, leaving apartments filled with potentially destructive condensation. And almost always, somebody is inconvenienced, whether it is the resident herself, who needs the radiator repair, or her neighbor, who unexpectedly finds herself in need of a wall repair. The good news is, such problems are often avoidable.  With some vigilance and by abiding some rule-of-thumbs, we can usually prevent these issues from happening or at least catch them before they cause serious damage.  

How to turn off your steam radiator:

Turn the radiator supply valve either all the way on (to the left) or all the way off (to the right).  Do not keep the valve turned halfway or somewhere in between.  The radiator valve, contrary to our wishes, does not regulate the heat other than turning it on or off.  Actually, it merely allows or stops the steam from entering the radiator.  While turning it off may help to resolve the problem when the room is too hot, doing so often can lead to an imbalanced system causing banging and clanging in the pipes.

 (If you'd like to know about other emergencies that may occur in your unit, click here to learn more.)

steam radiator valve

Keep this valve either all the way closed (clockwise) or all the way on (counterclockwise).

Check for water around the radiator.  While obvious, people often miss this.  Check the radiator and air valves for water leaks.  Even if the valves are new, this might mean simply that they need to be tightened.  Please report this promptly!


S-S-S-S-S-S-S-S!  While it's somewhat normal to have air escape with the sound of hissing through the air vent valves, this may be an indication that the radiator unit is imbalanced.  Under normal conditions, the radiator should warm up without such force of air.  So if you hear this hiss, please let us know.

air valve for steam radiator_hoffman 40

There are many types of air valves with different functions and for different locations. This one is a "Hoffman 40"

air valve on steam radiator_adjustable type

This air valve is an adjustable type, which means you adjust the size of the steam hole. In short, this valve can be installed on pretty much any radiator along the steam line.

Pitch perfect?  For radiators to operate efficiently and quietly, they must be pitched at an angle towards the supply valve.  If it is straight or slanted towards one side, the radiator may not be able to return the water collected inside the boiler, causing the clamor that keeps eyes wide open at night.


Finally, read the book by its cover.  Contrary to what our parents lectured, you can almost certainly read this radiator by its appearance.  If it's rusted, has a broken handle, or just looks like it has seen better days, your instinct to change this valve is keen!


If you've found an issue described above, or need any help in doing so, give us a call and we'll be happy to give you a hand.