How often should you bleed your radiators and check boiler pressure?

These tasks are more about efficiency, longevity, and comfort. Not a huge deal if you miss one, but it pays off over time.

Staying on schedule matters beyond the repair bill: a consistent maintenance record is one of the factors in a home's Roots Home Health Score, and well-kept homes typically sell faster and closer to asking price.

How to do it

Air trapped in a radiator leaves it cold at the top while the boiler works harder to heat the rest of the house. Bleeding releases the air; topping up the pressure keeps the system circulating.

1. With the heating off and radiators cool, hold a cloth under the bleed valve at the top corner of each radiator.
2. Turn the valve a quarter with a radiator key until air hisses out, then close it as soon as water appears.
3. Work from the lowest radiators up, and the ones nearest the boiler last.
4. Check the boiler pressure gauge afterward and top up to the normal range (usually around 1.0–1.5 bar) if it dropped.

Alternatives & optional extras

• Radiators cold at the bottom instead of the top signal sludge, not air; that needs a power flush, not bleeding.
• If pressure keeps dropping after topping up, there's a leak somewhere to trace.

Time: 30 minutes · Typical cost: $3–$8 for a radiator key

What you'll need

• Radiator bleed key

If you skip it

Trapped air leaves radiators cold at the top and forces the boiler to run longer to heat the house, wasting fuel.

Other boiler / radiators maintenance

• Schedule boiler service — once a year, ideally in September

Related systems to keep on schedule

• Furnace / heating system — start with: replace hvac air filter, every 3 months
• Mini-split / ductless AC — start with: clean mini-split filters, once a month
• Air conditioner — start with: schedule ac tune-up, once a year, ideally in April
• Tankless water heater — start with: descale tankless water heater, once a year