Central heating installation in Bromley

A full system in a two-bedroom flat or bungalow starts at £3,400 including VAT, a three-bedroom semi with eight or nine radiators from £4,600, and a four-bedroom house with a system boiler and unvented cylinder from £6,200. Installing central heating from scratch where there is no wet system at all starts at £5,400 because the gas run from the meter is part of the job. Those figures include the boiler, radiators, valves, pipework, controls, the flush and the Building Control notification. National guides quote around £5,250 for a three-bedroom gas installation, so we sit under the aggregator average, and unlike every other Bromley trade site in this market we publish the number.

Between £4,200 and £4,900 for most Bromley properties, including VAT, where the existing pipework is sound 15mm copper and the boiler stays roughly where it is. That covers a Worcester Bosch, Vaillant or Ideal combi, seven radiators sized from a heat loss calculation, thermostatic valves, a Boiler Plus compliant control, a system cleanse with inhibitor and a magnetic filter. Two things push it higher: microbore drops that need replacing at around £240 each, and a flue that has to move because of Part J clearances or a conservation area restriction.

They are different faults entirely. Cold at the top and hot at the bottom is air, which rises to the highest point in the panel — bleed it and repressurise to 1.2 bar and it costs nothing. Hot at the top and cold at the bottom is magnetite sludge lying in the bottom of the radiator with water flowing over it, and bleeding will not touch it; that needs the system cleaning. A radiator cold all over while the others are hot is usually a thermostatic valve pin seized down after the summer, which is under £100 to sort. And radiators nearest the boiler scalding while the far ones stay lukewarm is a balancing problem, not a fault at all.

Possibly, and it is the question nobody local answers. Bromley has over forty-five conservation areas, including five in Petts Wood plus Chislehurst, Bickley, Keston, Shortlands, Park Langley, Farnborough Village, Chelsfield and Downe, and several carry Article 4 directions that remove permitted development rights from front and side elevations. In those areas a flue terminal on a street-facing wall can require planning consent. A listed building needs listed building consent for the flue penetration and for an external condensate run. There are three usual routes round it: site the terminal on the rear elevation, run an internal vertical flue up through the roof plane, or use a plume management kit where the terminal has to sit close to a boundary or a neighbouring window. We identify which applies at survey, not on installation day.

Four documents, and you should have all of them. A Benchmark commissioning checklist, completed and stamped — a blank one voids most manufacturer warranties. A Building Regulations Compliance Certificate, which follows once we notify Building Control at Bromley Council through Gas Safe within thirty days. Confirmation that the manufacturer warranty has been registered. And your invoice showing the Gas Safe registration number, which for us is 919881 and is checkable on the register. Landlords also need a CP12 gas safety record annually. If an installer cannot produce the first two, the work has not been notified, and that becomes a problem when you sell the property.

It affects the hot water side considerably. The borough is supplied from the chalk aquifer at roughly 280 to 320 ppm, which is among the hardest water in the country. On a combi that means scale forming in the plate heat exchanger, and the usual symptom is a boiler that heats the radiators perfectly well but produces lukewarm or fluctuating hot water. The heating circuit itself is largely protected because it is a sealed loop with inhibitor in it, so the same water is not being replaced constantly. The part worth knowing is that several manufacturers make an inline scale reducer a condition of warranty above 200 ppm, so a combi fitted in Bromley without one may not be covered. We fit one on the cold mains as standard.

Yes, and it is worth asking about even if a heat pump is a decade away. The trick is designing at a lower flow temperature — around 50 to 55°C rather than the traditional 75 to 80°C — with radiators upsized to deliver the same heat output at that temperature. A gas boiler on that design condenses more of the time and costs less to run, so there is a benefit today. And if a heat pump goes in later, the emitters and pipework are already sized for it, which turns a full re-pipe into an appliance swap. The extra cost is larger radiator panels and a bigger cylinder coil, a small fraction of doing the distribution twice. We will price a conventional design and a heat-pump-ready one side by side.

Boiler Plus has been law in England since April 2018 and applies to every gas boiler installed in a domestic property. It sets a minimum ErP efficiency of 92% and requires time and temperature controls. On a combi installation it also requires one of four additional measures: load compensation, weather compensation, flue gas heat recovery, or a smart thermostat with automation and optimisation. It is a legal minimum, not an optional extra, and yet it appears on almost no quote and no national cost guide. Ask any installer you are comparing which of the four their price includes. If they cannot name it, either the installation will not be compliant or the cost is coming later.

Gas, by a wide margin, on current unit prices. Electricity costs roughly three to four times as much per kilowatt hour as mains gas, so even though electric heaters are close to 100% efficient at the point of use and a modern condensing gas boiler is around 90%, gas wins comfortably on running cost for a whole house. Electric systems make sense in specific situations: a flat with no gas supply, a property where the standing charge on a gas meter is not worth paying for one appliance, or a single room. A heat pump is the exception to the arithmetic, because it moves roughly three units of heat for every unit of electricity, which brings it close to gas on running cost and well under it on carbon.

Three to four days for a typical three-bedroom Bromley semi with eight or nine radiators, and five to six for a four-bedroom house with a cylinder. Installing from scratch where there is no wet system runs to a week, since the gas run and every pipe drop are new. A single day is enough only for a straight boiler swap onto existing pipework, which is a different job. We work in a sequence that gets the heating and hot water back on before we finish the making good, so you are not without either for the whole period.

You can carry out the plumbing side — running pipework, hanging radiators, fitting valves — but not the gas. Any work on a gas appliance or gas pipework must be carried out by a Gas Safe registered engineer under the Gas Safety (Installation and Use) Regulations. That is criminal law, not a trade convention. Unregistered gas work invalidates home insurance, cannot be notified to Building Control, and leaves you without the Building Regulations Compliance Certificate a buyer’s solicitor will ask for. It is also worth saying that the design side is where most DIY systems go wrong: undersized radiators, no balancing and no inhibitor produce a system that never quite works and cannot be diagnosed later.

Possibly, through ECO4, which is funded by the energy suppliers rather than by the installer. It generally requires a household member to receive a qualifying benefit and the property to have a poor energy rating, and it is aimed at first-time central heating and at replacing inefficient systems. The Boiler Upgrade Scheme is separate and covers heat pumps rather than gas boilers. Bromley Council also runs support schemes that change from year to year. We are not an ECO4 installer, so we will not be fitting a grant-funded system — but if you might qualify it is worth checking before paying privately, and we will tell you that rather than quote over the top of it.

Yes, for a full installation and for balancing. Every radiator has to be reachable to be hung, connected, bled and then set on its lockshield, including any boxed in, sitting behind a fitted wardrobe, in a loft conversion or in a locked room. On converted flats around Penge and Beckenham a radiator occasionally sits on a shared circuit in a neighbouring property, and that access needs arranging before we book a start date rather than on the morning. Where we genuinely cannot reach one, we say so on the quote instead of working round it.

Not automatically, and anyone who says yes without measuring is guessing. Sound radiators on a clean system will usually carry on for years. Two things do need checking. First, whether they are large enough for a condensing boiler running at a lower flow temperature — radiators sized for 82°C flow in the 1970s are undersized for 60°C, and that shows up as rooms taking too long to warm. Second, whether the drops are microbore, which is common in the Petts Wood and Orpington estates and restricts flow enough to matter. Both are answered by a heat loss calculation at survey, which is a lot cheaper than finding out after the new boiler underperforms.