Boiler Repair South London
Gas Safe registered engineer covering Wandsworth, Clapham, Brixton, Lewisham, Greenwich and surrounding South London areas. Same-day call-outs, honest diagnosis, fixed price before any repair begins.
Boiler repair you can rely on across South London
When your boiler breaks down, you need a qualified engineer quickly — not a week's wait and a vague estimate. R.W. Miller Plumbing & Heating offers boiler repair across South London, covering SW4, SW8, SW11, SW12, SW17, SW18, SE1, SE5, SE15, SE21, SE22, SE24 and surrounding postcodes. Reion is Gas Safe registered (number 919881) and carries parts for the most common boiler faults on every call-out.
The Boiler Faults Reion Repairs Most in South London
Diverter valve failure
Stops the boiler switching cleanly between heating and hot water, so one works but not the other. Usually a same-day part swap.
Ignition lockout
A fan, sensor, or electrode fault trips the boiler into a safety lockout. The most common cause behind a 'no heat, no hot water' call-out.
Expansion vessel failure
Pressure creeps up when the heating runs, then drops overnight. Thames Water's hard water corrodes the vessel membrane faster in Wandsworth, Lambeth, and Southwark.
Pump failure or seizure
Radiators stay cold even though the boiler fires. Hard water corrosion is the leading local cause of a seized pump.
Limescale on the heat exchanger
The usual cause of kettling and banging noises. A system flush with an inline scale reducer resolves it for good.
PCB (control board) fault
Erratic fault codes or a boiler that ignores the thermostat. We test the board before replacing it. A full PCB isn't always needed.
Gas valve fault
Boiler won't ignite or cuts out under load. This is Gas Safe-registered work only. Never attempt it yourself.
Every visit starts with a thorough diagnosis. The £80 diagnostic fee covers the first hour on-site — this includes identifying the fault and carrying out any minor adjustments. If parts or additional labour are needed, a fixed price is agreed before work begins. No hidden charges, no surprises on the invoice.
Whether your boiler has lost pressure, is making unusual noises, won't fire up, or is displaying a fault code, call 07375 813996 and speak directly with Reion. Not a call centre — the engineer you speak to is the engineer who arrives.
Signs your boiler needs a repair
What to expect when you call
Same-day call-out
Call 07375 813996 and we aim to reach you the same day across all South London postcodes. We carry common spare parts on every visit so many repairs are completed on the first call-out.
Full diagnosis
The £80 fee covers a complete inspection of your boiler and heating system. We identify the exact fault accurately before recommending any repair work.
Fixed-price quote
Once we know what is wrong, we give you a clear fixed price before touching anything further. You decide whether to proceed — no pressure, no obligation.
Repair and test
We complete the repair and fully test the system before leaving, including flue gas analysis where required. A job sheet confirms everything done.
Frequently asked questions
How much does boiler repair cost in South London?
Can you repair all boiler makes and models?
How quickly can you respond to a boiler breakdown in South London?
Is it worth repairing my old boiler or should I replace it?
Do you offer 24-hour emergency boiler repair in South London?
Diagnose your boiler fault
Not sure what's wrong? Look up your boiler's error code for a step-by-step breakdown of what it means and what to do next.
All boiler fault guides →Trusted by homeowners and landlords across South London
Reion came out the same day to fix a boiler fault that had left us with no hot water. Quick diagnosis, clear explanation of the problem, and had it fixed within the hour. Excellent service.
Called about a leak under the kitchen sink. Arrived within two hours, sorted it cleanly and charged exactly what was quoted. Will definitely use again.
Used R.W. Miller for the annual gas safety certificate on my rental property. Professional, punctual, and had the CP12 over the same day. My go-to for all landlord checks.
Central heating stopped working in January. Called in the evening and Reion was with us first thing the next morning. Fixed within 30 minutes. Highly recommend.
Very professional service. Transparent about pricing before starting work. Cleaned up afterwards too. Would not hesitate to use again.
Boiler not working? Call South London's Gas Safe engineer
Gas Safe registered (919881). Same-day response across South London. Fixed price before any repair starts. Call 07375 813996 or send a message and we will get back to you fast.