How do I bleed air from my radiators?

Bleeding air from radiators is a straightforward maintenance task that can improve your heating system's efficiency. You'll need a radiator key (available at hardware stores), a cloth or towel, and a small container to catch water.

Start with your heating system turned off and radiators cool to the touch. Locate the bleed valve at the top of each radiator - it's typically a small square or hexagonal fitting. Begin with the radiators on the lowest floor of your home and work your way up, as air naturally rises through the system.

Insert the radiator key into the bleed valve and turn it counterclockwise about a quarter turn. You should hear air hissing out - this is normal. Keep the valve open until water starts to flow steadily, then immediately close it by turning clockwise. Be ready with your cloth and container, as some water will come out. The water may be discolored initially, which is normal.

After bleeding all radiators, check your boiler's pressure gauge. In Ottawa homes with hydronic heating systems, the pressure should typically read between 12-15 PSI when cold. If the pressure has dropped significantly after bleeding, you may need to add water to the system through the fill valve, though this should be done carefully to avoid overpressurization.

If you're uncomfortable with this process or notice persistent issues like radiators that won't heat evenly after bleeding, it's time to call a professional. Problems with your hydronic heating system can indicate issues with the circulator pump, expansion tank, or other components that require licensed technician attention. For complex heating system issues in Ottawa, consider having your system inspected to ensure optimal performance through our cold winters.

---

Find a HVAC Contractor

Ottawa HVAC Pro connects you with experienced contractors through the https://justynrookcontracting.com:

• RenoMotion Inc. ✓
• Pure Flow Water Solutions inc. ✓
• B.A Gas Works ✓