Commercial · London & Herts
Radiator repair in London
The short answer
A radiator that's cold at the top needs bleeding to release trapped air. Cold at the bottom usually means sludge. One radiator cold while others are hot often points to a stuck valve or an unbalanced system. Leaks are usually at the valves or joints, but pinholes in a corroded radiator mean it needs replacing.
Radiators that don't heat properly waste energy and leave rooms cold. We repair leaks, replace valves, bleed and balance systems, and replace radiators that are beyond repair.
We work on everything from traditional cast-iron radiators to modern designer models and towel rails, for homes and commercial premises.
How it works
Radiator repair: what happens when you call
- 01
Call or message us
Tell us about the radiator problem. Phone, WhatsApp or book online, 24 hours a day. We'll ask a few quick questions and tell you when we can be there.
- 02
Diagnosis and quote
The engineer finds the cause of the radiator fault, explains it in plain English and gives you a clear quote before any work starts.
- 03
Repair and clean-up
We repair or replace the radiator and rebalance the system, test everything, tidy up and talk you through how to avoid it happening again.
FAQs
Radiator repair questions, answered
Why is my radiator cold at the top?
Air is trapped inside. Bleed the radiator with a radiator key while the heating is off: open the bleed valve until air stops hissing and water appears, then close it. On a sealed system, check the boiler pressure afterwards and top it up if it's below 1 bar.
Why is one radiator cold when the others are hot?
Check the thermostatic valve isn't turned off or stuck. TRV pins often seize after summer. If the valve is fine, the radiator may need bleeding, or the system may need balancing so hot water reaches every radiator evenly. Cold bottoms suggest sludge, which a power flush clears.
Can a leaking radiator be repaired?
Leaks from valves, the bleed screw or pipe joints can usually be repaired by tightening, re-sealing or replacing the valve. A leak from the radiator body itself, often a pinhole caused by internal corrosion, means the radiator needs replacing.
What customers say
All 165 reviewsEljo from Urgent Plumbers London Ltd is one of, if not the most responsive tradesman I've come across - replied to queries and messages quickly without fuss, and clearly explained issues/reasoning with any work required. Always arrived when he said he would too and was happy to provide all relevant documentation (Gas Safe etc) when asked - would recommend. Quoted for boiler service/replaced our boiler when it was found to be un-serviceable.
Urgent Plumbers were fantastic when my boiler leaked. It was at the worst time possible -early on a Sunday morning when I was rushing out to work. He was so calm , turned up quickly as promised and then was so efficient at working out and fixing the problem. He was also so kind as I was terrified how much it would all cost for a Sunday emergency call out Thank you so much - you're an absolute hero
I'm really pleased with the service. All in the same day the gentleman came to fix an issue in the bathroom. A leaking pipe fixed. Very friendly and professional. I totally recommend their service. Thanks again 😊
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Radiator repair near you
Radiator repair? We can help today.
Call any time, day or night. We'll tell you when we can be there and give you a clear price before we start.