Central heating engineers in London
Heating that will not come up to temperature, cold radiators, noisy pipework and full system installs.
Service overview
Most central heating complaints are circulation problems rather than boiler problems. The boiler fires, the water gets hot, and something stops that heat reaching the rooms you want warm.
Working out which of those it is takes a few minutes with a thermometer and a look at the pipework, and it saves people spending money on a boiler that was never the problem.
We handle repairs, upgrades and full system installs across London, on everything from a two-bed flat to a period house with a hundred metres of pipe run.
We work across Greater London and north Surrey, including Croydon, Bromley, Sutton, Orpington and Wimbledon. Gas Safe engineers do every gas job. See the gallery, about us or get in touch.
Get a quoteSigns you need central heating
- Radiators cold at the top, or cold at the bottom
- Upstairs warm and downstairs cold, or the reverse
- The system takes hours to come up to temperature
- Banging, gurgling or kettling from the pipework
- One radiator never gets hot no matter what you do
- Hot water fine, heating not working at all
Cold at the top or cold at the bottom
It is the single most useful thing a homeowner can tell us on the phone, because the two mean completely different things. Cold at the top is air, and bleeding the radiator usually sorts it. If it keeps filling with air, something is drawing air into the system and that wants finding.
Cold at the bottom is sludge. Iron oxide settles out of the system water and builds up in the bottom of the radiator where the flow is slowest, so the top gets hot and the bottom never does. Bleeding it achieves nothing. That is a cleaning job, and if it is happening across several radiators it points at a system that needs a power flush and proper inhibitor.
Balancing, pumps and controls
When some rooms heat and others do not, and there is no air or sludge to blame, the system usually needs balancing. Radiators nearest the pump take the easiest path and get more than their share of flow; the far end of the circuit gets starved. Balancing sets the lockshield valves so each radiator takes what it should. It is unglamorous work and it fixes a great many complaints.
The other candidates are the pump and the controls. A pump that runs but has lost its impeller performance will heat the near end of the system and nothing else. Domestic pipework is typically 15mm to most radiators and 22mm on the main runs, and a system extended over the years without upsizing the main run will struggle no matter how good the pump is.
Hot water cylinders
Where a property has a cylinder rather than a combi, hot water problems are usually the coil, the thermostat or the immersion rather than the boiler. Stored water wants to sit at 60°C, which is the temperature that controls legionella, with distribution at 50°C or above.
Unvented cylinders are a separate qualification. Building Regulations Part G3 covers them and not every gas engineer holds it. If your cylinder is unvented, the discharge arrangements and the safety valves need someone qualified to touch them.
How the visit goes
Find the actual fault
Flow and return temperatures, pump performance and radiator behaviour, before anything is replaced.
Tell you what it is
Air, sludge, balancing, pump or controls. Each is a different job at a different cost.
Do the work
From a balance and a bleed through to a full system install with new pipework.
Leave it protected
Inhibitor dosed and checked so the problem does not come straight back.
Standards this work is held to
BS 7593:2019
System water treatment: clean, dose with inhibitor, fit a filter, and verify the inhibitor level annually.
Building Regulations Part G3
Unvented hot water cylinders require separate G3 competence to install or work on.
Stored water at 60°C
Hot water stored at 60°C and distributed at 50°C or above is what controls legionella risk in a cylinder system.
Central heating: common questions
Related to Central heating
Areas we cover
We work across Greater London and north Surrey, including Croydon, Bromley, Sutton, Orpington and Wimbledon. Pick your town.
Need an emergency plumber?
Burst pipes, boiler breakdowns and blocked drains across Greater London. We aim to be with you within 60 minutes.