Air Locked Heating System
Air trapped in your heating system prevents hot water from circulating properly, leaving radiators cold at the top while the boiler runs normally. This common issue affects homes across Greater Vancouver — especially after system maintenance, draining, or when the boiler is refilled. Our licensed technicians diagnose and fix air locks fast.
While bleeding a radiator is a simple DIY task, persistent air locks often signal a deeper issue such as a leaking expansion vessel, faulty automatic air vent, or poor system design. Our gas-certified technicians trace the root cause and fix it permanently, not just temporarily.
What Causes Air Locks in a Heating System
Air enters your heating system through leaks, during maintenance, or when system water is replaced. Common causes include a leaking expansion vessel, corroded pipework, a failed automatic air vent, or simply refilling the system after draining. Homes with multiple floors are especially prone to air collecting in upstairs radiators.
- System refilling after repairs creates air pockets
- Leaking expansion vessel allows air ingress
- Failed automatic air vents stop releasing trapped air
- Corrosion produces hydrogen gas that mimics air locks
- Higher floors trap air in radiator tops
Our Air Lock Repair Process
We start by checking your system pressure, expansion vessel condition, and automatic air vents. We bleed all radiators starting from the lowest floor, then check for recurring air ingress after the boiler cycles. If air returns quickly, we know there's an underlying leak or component failure requiring repair.
- Full system diagnostic and pressure check
- Radiator bleeding — all floors, all rooms
- Automatic air vent inspection
- Expansion vessel condition assessment
- Root cause fix, not just symptom treatment
This is not a DIY repair
Combi boilers are gas-fired appliances regulated under the BC Safety Standards Act. Opening the unit, touching the gas valve, or working on the flue without a valid BC gas-fitter licence is both unsafe and illegal. Diagnosing the fault is helpful — fixing it should always be left to a certified technician.
Call 778-909-5731Frequently Asked Questions
Talk to a Licensed Combi Boiler Specialist
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