Steam Radiators

Maintaining steam radiators to avoid banging and whistling

Even as newer heating systems have been developed, many residences continue to use steam heat to stay warm during the winter. The radiators in these systems are often durable enough to have lasted several decades, and maintaining them can be much more cost-effective than replacing them. In addition, many homeowners enjoy them because they lend some rustic charm to the home and won't kick up allergens.

At the same time, steam heating systems have some drawbacks that can prove aggravating. The heat might be inefficient or uneven if the system isn't working properly. Radiators can also spring leaks or produce loud hissing or banging noises.

One of the best ways to avoid problems with a steam heating system is to have it regularly serviced by a professional. The home improvement site HomeAdvisor says an annual inspection will make sure the controls, gauges, and boiler are all working properly. This inspection might also extend to the radiators to make sure their valves are correctly adjusted.

In a steam heating system, a boiler converts water to steam, which is piped to radiators throughout the home to radiate heat. Once the steam cools down, it condenses into water which drains back to the boiler. Some radiators have a single pipe which both brings in steam and lets condensed water out, while others have one pipe for steam intake and another for water removal.

The system can operate under minimal pressure. Dan Holohan, writing for Old House Journal, says you should be able to heat your house with a pressure of just two pounds per square inch. Increasing the pressure will not only lead to a higher fuel bill, but increase the possibility of leaks.

If some radiators are not heating up, the likely cause is trapped air. The magazine Family Handyman says this issue can be remedied by bleeding air from the affected radiators. Some radiators require a special key for this purpose, while other valves can be opened with a flat screwdriver.

The valve should be kept open until water starts dripping out. It helps to have a towel or cup handy to keep too much water from spilling onto the floor.

Since bleeding air will reduce the pressure in the heating system, especially if you are working on multiple radiators, it helps to have a second person keeping an eye on the pressure gauge on the boiler. More water should be added to the boiler as necessary to maintain pressure.

A radiator will also do a poor job of heating a space if its air valve is not working properly. The Department of Energy says these devices are used to automatically bleed air from the radiator, but will prevent a radiator from heating if they become clogged.

While a non-functioning air valve may need to be replaced, it can sometimes be fixed with a simple cleaning. Bob Formisano, writing for the home design site The Spruce, says you can remove the valve from the radiator and soak it in warm vinegar to loosen any rust or mineral deposits. After rinsing off the valve and blowing into it to make sure it functions properly, you can reattach the device to the radiator.

The valve should be facing up after it has been screwed back on. This Old House recommends wrapping Teflon tape around the threads of the new valve for a more efficient seal.

It is common for a radiator to produce a knocking, clanging, or banging sound if condensed water is not draining properly. Joseph Truini, writing for Popular Mechanics, says that as steam enters the radiator this water is propelled forward at a high speed, producing loud noises when it comes into contact with valves or other plumbing fittings.

Although radiators are installed at a slight angle to allow water to drain properly, they may work themselves out of alignment over time. The Department of Energy says the thermal expansion and contraction of a radiator can cause it to gradually create ruts in the floor, allowing the radiator to sit at an improper angle.

The simplest way to restore adequate drainage is to put shims under the radiators' feet. In a single pipe radiator, the radiator should be angled toward the one pipe in the system. When two pipes are present, pitch the radiator away from the steam intake.

Periodically check your radiators for signs of leaks. If left unrepaired, this problem can cause expensive water damage to the floors and ceilings of your home.

Water leaks may occur at the valve stem, where steam enters the radiator near the floor. This Old House says that you can remove the handle and packing nut from the valve stem, wrap graphite packing around the threaded part of the valve stem, and then reattach the packing nut and handle to create a tighter seal.

Small leaks may also form elsewhere in the radiator. Holohan says one option is to drain the radiator, remove any paint or rust from the area of the leak, and apply an epoxy to the leak.

Maintenance should only be conducted when the heating system is turned off to avoid the possibility of burns or other problems. You should also consult with a professional if you are not comfortable working on a steam heating system on your own.