Central Heating

A central heating system consists of all the pipework and radiators that are connected to the boiler. The boiler provides the heat but it's the pump (circulator) that moves the heated water from the boiler through pipework to the radiators. It is then pumped back to the boiler for re-heating.

There are many types of system that can be installed into your home which may be tailored to your own preferences. A carefully designed and installed system will give many years of trouble free heating and will be energy efficient, therefore keeping your fuel costs lower.

Your London Gas engineer will be able to help and advise you choose the best system for your home.

  • Fully pumped system
  • Combination boiler system
  • Gravity hot water pumped heating
  • Independent water and heating
  • Thermal heat store


It is important that your boiler should be matched to the size of your property. If the boiler is oversized your fuel bills will be excessive. If the boiler is undersized it may not generate enough heat in the winter months. The ideal size for a boiler is one that copes adequately on the coldest day of the year. 

Your London Gas engineer will be able to advise and help you choose the correct boiler for your home. 

All gas appliances should be checked for safety once a year, any faults or potential faults will be picked up and rectified. 
  • Condensing
  • Condensing conventional
  • Combination
  • Water heaters
  • Cast iron boilers

Underfloor Heating

Underfloor heating works by pumping a controlled flow of warm water from any heat source through plastic tubing embedded in the floor. As the emitting area is large sufficient warmth is provided even on cold winter days with no need for supplementary heating. 

Underfloor heating delivers a near perfect temperature profile between floor and ceiling due to a balanced combination of radiant and confected heat.

Benefits to underfloor heating include hygiene due to low moisture. It is possible to have energy saving from 15% to 40% and underfloor heating systems are very easy to control.

Our engineers are certified underfloor heating installers and will be able to discuss all issues with you. 


There is a large choice of radiator styles. It doesn't matter which type you choose providing the heat output of the radiator(s) meets the needs of the room. 

Before choosing your radiators you must determine how much heat each room requires. Your London Gas engineer will be able to do this when quoting. The best calculations take every measurement of every room especially the window sizes and outside wall sizes. Too big and the system will overshoot its temperature and be less economical to run. Too small and the room won't reach its desired temperature. The best place for a radiator is in the coldest part of the room which is usually under a window. 

Radiators do not burn gas, therefore turning radiators off will not save you money. In fact it will probably increase your fuel bill as this will create cold drafts in your home.


Most modern cylinders come with foam lagging bonded on to the outside of the cylinder. This is extremely efficient insulator and will keep the water hot for a long time. There are a lot of different shapes and sizes to suit the space available, but the capacity of the cylinder is important.

There are two main types of hot water cylinders: unvented hot water and vented hot water. Unvented cylinders are fed from the mains whereas vented are fed from a cold water tank usually found in the loft space.

These two types can be either direct cylinders or indirect cylinders, this refers to the way they heat the water. Direct hot water cylinders heat water directly with an immersion heater fitted into the hot water cylinder. An indirect cylinder heats the water via a heat exchanger. This is a coil of pipe that runs through the water cylinder. This coil is heated from the central heating system. 

Talk to your London Gas engineer who will be able to advise you which cylinder is best suited to your home.


Over time central heating systems can become contaminated with rust, sludge and other debris caused by internal corrosion. This corrosion can cause circulation and boiler noise problems, premature failures of heating system components and a reduction of system efficiency. Central heating systems need to be flushed and cleaned from time to time and the best way to do this is power flushing. 

To help keep your system in its best condition your London Gas engineer will offer to install a cleaning filter to your system. We are MagnaClean approved installers.

The MagnaClean magnetic filter protects the boiler; thus reducing breakdowns in the most expensive part of the system, and it prevents build up of iron oxide sludge in the radiators that would otherwise make them less efficient

Inspections and Certificates

A gas safety certificate tells you that the gas appliance or gas fitting has been checked to see if it is working safely and meets the correct safety standards. This information may also tell you when you next need to service the appliance.

It's important to get your appliance regularly serviced to make sure they are working efficiently and safely. You should also have a gas safety check done on all gas fittings and appliances every year.

Do you live in a rented property?

Your landlord is responsible for your gas safety. If you rent a property ask your landlord for a copy of the current Gas Safe record (CP12). This record shows that gas appliances have had an annual gas safety check by a Gas Safe registered engineer. Landlords must maintain all gas appliances so check the date and when it was last serviced.

Are you a landlord?

Landlords must be able to provide their tenants with an up to date Gas Safety record (CP12). By law, landlords must have all gas appliances serviced once a year by a Gas Safe registered engineer. The Gas Safe engineer will provide a Gas Safety record upon completion of the check. 

All rights reserved. London Gas

© 2022