Radiator troubleshooting guides
Diagnose radiator problems including cold radiators, trapped air, balancing issues and heating circulation faults.
Common problems
Radiators are warm but the house still feels cold
Advice Hub / Radiators Radiators are warm but the house still feels cold Check time: 10–15 minutes • Difficulty: Easy checks • Safety: Low risk Quick answer If your radiators feel warm but rooms still feel cold, the issue may not be the heating system at all — it could be thermostat placement, room insulation,…
Radiator balancing explained
Advice Hub / Radiators Radiator balancing explained Check time: 5 minutes • Difficulty: Easy checks • Safety: Low risk Quick answer Balancing is the process of adjusting radiators so that hot water flows evenly around your heating system, rather than the nearest or largest radiators taking most of the flow and leaving others lukewarm. It’s…
TRV valve faults explained
Advice Hub / Radiators TRV valve faults explained Check time: 5 minutes • Difficulty: Easy checks • Safety: Low risk Quick answer A TRV (thermostatic radiator valve) is the valve, usually with a numbered dial, that controls how much hot water flows into a radiator based on room temperature. When it faults, a radiator might…
Radiator valve leaking: what to check and when to call a plumber
Advice Hub / Radiators Radiator valve leaking: what to check and when to call a plumber Check time: 5–10 minutes • Difficulty: Easy checks • Safety: Medium risk Quick answer A leaking radiator valve is usually caused by a worn seal, a loose connection, or a valve that’s not fully closed. In many cases you…
Radiator not heating after bleeding: what to check
Advice Hub / Radiators Radiator not heating after bleeding: what to check Check time: 5–10 minutes • Difficulty: Easy checks • Safety: Low risk Quick answer If a radiator is still cold after bleeding, trapped air likely wasn’t the actual cause — the real issue may be a closed valve, restricted flow, or sludge inside…
Radiator whistling or banging when heating is on: common causes
Advice Hub / Radiators Radiator whistling or banging when heating is on: common causes Check time: 5–10 minutes • Difficulty: Easy checks • Safety: Low risk Quick answer Whistling from a radiator is often caused by water moving fast through a nearly-closed valve, while banging can be linked to trapped air, pipework expanding as it…
Radiator cold at the bottom: sludge or circulation?
Advice Hub / Radiators Radiator cold at the bottom: sludge or circulation? Check time: 5–10 minutes • Difficulty: Easy checks • Safety: Low risk Quick answer A radiator that’s warm at the top but cold at the bottom points away from trapped air and more towards restricted flow or a build-up of sludge inside the…
One radiator not heating: valves, air, or balancing
Advice Hub / Radiators One radiator not heating: valves, air, or balancing Check time: 5–10 minutes • Difficulty: Easy checks • Safety: Low risk Quick answer If just one radiator won’t heat up while the rest of the system works fine, the likely causes are a closed or stuck valve, trapped air, or that radiator…
Heating upstairs but not downstairs: circulation and balancing checks
Advice Hub / Boilers & Heating Heating upstairs but not downstairs: circulation and balancing checks Check time: 5–10 minutes • Difficulty: Easy checks • Safety: Low risk Quick answer Heating that works upstairs but not downstairs (or vice versa) is usually about how hot water is distributed around the system, not a thermostat fault. Check…
Radiator cold at the top: air vs circulation
Advice Hub / Radiators Radiator cold at the top: air vs circulation Check time: 5–10 minutes • Difficulty: Easy checks • Safety: Low risk Quick answer A radiator that’s cold at the top but warm lower down usually has trapped air inside, which bleeding often resolves. If it’s cold at the bottom instead, the cause…