Vent, Valve & Volt
Vent: HVAC

Radiator or baseboard heat not working

Radiator and baseboard heat comes in three kinds: hot-water systems and steam systems that run off a boiler, and electric baseboard heaters. Let's figure out which one you have, how much of the home is cold, and what is safe for you to try. Anything at the boiler itself is a job for a heating pro.

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Before you start. If you smell gas or rotten eggs, see smoke or flames, hear a carbon monoxide alarm, or anyone feels dizzy or sick, get everyone outside and call 911 from outside. Do not touch switches on the way out.
Every question and answer on this page, in order

Question 1: What do you notice right now?

Pick the first one that fits. A working radiator is hot to the touch, so heat alone is not a warning sign.

Question 2: What kind of heat do you have?

Electric baseboard heaters are wired into the wall and have no pipes. Hot-water and steam systems both run off a boiler. This Old House says a steam radiator has an air vent on its side, and a hot-water radiator usually has a small bleed valve at the top.

Question 3: Have you set the thermostat a few degrees above the room temperature, waited, and checked that the heater's breaker is on?

Cadet says baseboard heaters generally take 30 to 60 minutes to heat a room. A tripped breaker handle sits in the middle or at OFF. Open only the hinged door on the panel.

Question 4: How much of the home is cold?

Feel each radiator or baseboard briefly and carefully, since they can be hot.

Question 5: How much of the home is cold?

Feel each radiator briefly and carefully. New York City's housing department says steam radiators can reach 220 degrees F.

Question 6: Does the heater have metal pipes or a water line running to it, or only a cable going into the wall?

Question 7: Look at that radiator's own hand valve at its base, or the thermostatic valve head if it has one. Is it fully open?

Turn it by hand only and never force it. NYCHA tells residents to turn the knob to the left to open it. A baseboard may have a damper or control louver instead, so make sure that is open too.

Question 8: Look at that radiator's hand valve at its base. Is it fully open?

Turn it by hand only and never force it. This Old House says a partly closed valve is often behind a whistling steam radiator and to check that the valve is fully open or fully closed, so for heat make it fully open. Leave the small air vent on the side of the radiator alone.

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