Leaking Radiator — What to Do Right Now
Radiator leaks stain floors and ceilings fast, but they're rarely a full emergency — you almost always have time to protect the floor and message us before it gets serious.
Make it safe — before anything else
Close both valves
The valve at each end of the rad. This isolates just that radiator from the rest of the system — the boiler and every other rad keep working.
Protect the floor
A rusty radiator leak stains permanently. Bowl under the drip, towels around the base, lift any rug or bathmat immediately.
Don't top up the boiler
If pressure drops, resist the urge to top up. Adding water to a leaking system just adds to the flood.
Photograph before you clean
Water damage, valve position, model number. Useful for us and for any insurance claim.
What Kevin (our AI) will check first
Message Kevin and he'll ask exactly these questions before we send an engineer, so we bring the right parts on the first van.
- Where is the leak — valve, spindle, bleed screw, or the radiator body itself?
- Age and type of radiator (steel panel, cast iron, designer aluminium)?
- Any signs of internal corrosion — brown, sludgy water when you catch a drip?
- Is the system's inhibitor level right — has it been flushed in the last 5 years?
- One radiator or several — could it be an expansion / pressure problem across the whole system?
Common causes of a radiator leak
Failed valve gland
The spindle packing inside a rad valve dries out and starts weeping. Usually a 15-minute repack or a valve swap.
Pinhole corrosion
Old steel rads corrode from the inside out — usually in the bottom third. Pinholes can't be reliably patched; the rad needs replacing.
Loose union nut
The nut connecting the valve to the rad tail can weep after a temperature swing. Tighten and re-verify, don't over-torque.
Bleed screw weeping
A worn or over-tightened bleed nipple can drip. Cheap and quick to replace.
System pressure too high
If the boiler is set above 2.5 bar cold, weak spots on old rads let go. Diagnose the expansion vessel, not just the leak.
Honest cost band — why we won't quote blind
Typical
£95 – £220 for a valve repack, valve swap or bleed-screw fix
Complex
Full radiator replacement (like-for-like) £220 – £480 including drain-down, refit and refill with inhibitor.
A dripping valve looks the same as a corroded rad body from a photo. £50 diagnostic gets you a written fixed price for the actual failure, not a guess.
Fixed £50 diagnostic
Flat fee. No hourly meter running.
Fair quote or refund
Transparent pricing — refunded if we don't fix it.
Vetted UK engineers
DBS-checked, insured, real reviews.
AI-triaged in seconds
KJ chats first so the right engineer arrives.
Related emergencies
See all in the emergency plumbing hub — or the leaks & water damage hub.
Areas we cover for radiator leak
Same-day across Greater Manchester and Rochdale.
Radiator leak — FAQs
Dealing with a radiator leak? Chat with Kevin now
Real triage in seconds. £50 diagnostic visit — refunded if we don't fix it.
Related hubs: emergency plumbing, leaks & water damage, all services.
Chat with Kevin about Radiator leak