What To Do When One Hot Water Radiator Doesn’t Get Hot

Does one of your hot water radiators refuse to heat up, even when the rest of the system seems to be working fine? Chances are, there’s air trapped in the radiator, preventing the hot water from filling it properly. This is a problem you can generally solve yourself by bleeding the air out of the radiator. Follow these steps:

  1. Obtain a radiator key. If you don’t have a key for your radiator, you may be able to find one at a local hardware store. Some bleed valves even fit a plain screwdriver, so try this out before you buy. (The bleed valve is typically located just an inch or two from the top of the radiator.)
  2. Place a pan under the radiator to catch any water that drips out.
  3. Turn the key about a quarter turn to the left. You should feel air seep out. When water starts dripping out, turn the key back to its starting point.

Now that your radiator has been bled, hot water should fill it properly, so it should get warm when your heat is on. If the radiator still does not get hot, there may be an issue with the pipes leading to the unit. Have your heating contractor out to inspect the system and figure out what’s wrong.

It’s a good idea to bleed all of your radiators at the beginning of the heating season. If you release a lot of air from the system, you may have to add water back to the boiler to increase pressure. If you’re not familiar with how to do this, contact Metro Heating & Cooling.