De Dietrich System Imbalance / Air Lock

Furnace runs but some radiators remain completely cold

Possible Causes

Air trapped in specific radiators, Closed lockshield valves, Incorrect balancing of De Dietrich heating circuit, Blocked branch pipe

Safety: Radiators may be hot; use a cloth when bleeding.

Steps:

Bleed cold radiators: Use a radiator key to release air until water flows.
Check valves: Ensure both TRV and lockshield valves are open on cold radiators.
Balance system: Slightly close valves on radiators that heat quickly to force more flow to cold ones.

Professional help: If a radiator remains cold, a technician should check for blockages or pipework issues.

Easy 2/5