0755 791 0404 contact@lsaheating.co.uk

Boiler Installation London

Heating Boilers in London at Competitive Prices


Who we are

Skilled plumbers, gas units experts and heating engineers, with over 30 years experience in heating, gas and plumbing services.

What we do

Boiler installation

Regular boiler to combi boiler conversion
Unvented cylinder installation
Underfloor heating system installation
Repairing household gas, plumbing and heating units

Areas served

North London

South London

West London

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Quality Services

Checkatrade information for LSA Heating

Why chose LSA Heating

Deposit protection
Backed insurance guarantee
Trusted tradesman (vetted and monitored)
Liability insurance up to 2.000.000
Fully qualified tradesmen
Warranty on every job undertaken
Friendly advices for our customers


Vaillant approved installer

Up to 10 years parts and labour warranty


Ideal approved installer

Up to 10 years parts and labour warranty


Glow worm approved installer

Up to 15 years parts and labour warranty


Baxi approved installer

Up to 10 years warranty


Lifetime warranty for unvented cylinders
Up to 25 years warranty on underfloor heating installation

LSA Heating is member of

gas safe   power flush association   which   yell   checkatrade   vaillant advance   installer connect   club energy   glow worm   baxi


Boiler sizes

An over-sized boiler is inefficient.


Boilers should be sized to provide sufficient heat and hot water, and warm the dwelling to the required comfort temperatures when the temperature outside is below freezing. (Historically, this has been -1C although more recently -3C is being recommended).

This means that for most of the heating season, during the times of day when comfort temperatures are required, the boiler will produce more heat than can be used by the system.

The heat excess to requirements is lost via the flue through convection. The cooler air entering at the base of the boiler cools it so that it fires-up again, even if the system does not need any heat at that time. When the internal thermostat is up to temperature the burner is switched off, but the heat produced is going nowhere except out of the flue. The boiler is doing what is known as short-cycling.
If a boiler is over-sized even when it is freezing outside, the amount of heat wasted is significantly increased throughout all of the heating season.

Further calculation may be needed to ensure unnecessary over-sizing or under-sizing does not occur.

  • As a rough estimate most flats, apartments and smaller houses, with up to 10 average size radiators will require a 24 to 27kw Combi Boiler.
  • For a medium to large 3-4 bed house with up to 15 average size radiators a 28-34kw Combi Boiler would be installed.
  • For a large house with anything up to 20 average size radiators a 35kw and a 42kw Combi Boiler would be installed.

For properties where a higher demand of hot water is needed the higher the kw of the boiler the better, however combi boilers do not cope well with 2 or more hot water outlet running at the same time in the same property. Only combi storage boilers are design to run 2 shower at same time. Where this is a requirement a system boiler with an unvented cylinder should be considered.

Boiler types


How they work: Combis work as sealed systems, providing hot water for both the taps and central heating system, heating the water directly from the mains as and when it is needed – meaning there is no need for a hot water storage cylinder or a cistern in the roof space.

Advantages: Combis are quicker, easier and cheaper to fit than system boilers, as well as space saving due to the lack of a cylinder or cistern. Water is delivered at mains pressure, so you can enjoy a more powerful (although not “power”) shower.

Disadvantages: It’s a priority system so it only satisfactorily deals with one heating need at a time. While fine for small families with one bathroom, larger families will experience poor flow rates when multiple outlets are used at once. Performance is also dependant on the diameter of the pipe entering the property: if it’s less than 22mm, then a combi is a bad choice.


How they work: System boilers are fitted to sealed heating systems, but unlike Combis work on the principle of storing hot water in a cylinder, so they can feed several outlets at once at mains pressure. There’s no need for a cistern in the loft and the expansion vessel is built in.

Advantages: Ideal for larger homes with higher demands, and as they have most of their major components built in (i.e. expansion vessel and pump), installation is quicker, cheaper and neater. Flow rates are usually high as water is delivered at mains pressure, and hot water is instantaneous.

Disadvantages: Use of space for storage cylinder.

Regular / Conventional

How they work: Regular boilers are now largely bought as replacements for homes with an open-vented heating system (i.e. supplied by means of a feed and expansion cistern in the roof space, meaning the system is open to air). Like system boilers, they work on the principle of stored water and require a separate hot water cylinder.

Advantages: The water out of the taps will be at a good flow rate (not to be confused with pressure) and hot water can be supplied instantaneously. This is the ideal setup for a “power” shower, which requires a cold water feed from the cistern and a separate electric pump.

Disadvantages: They’re more expensive to install, needing more components and pipework, and also take up more space. They can suffer from low pressure if the cistern is not located high enough, meaning additional shower boosters may be required. Hot water can run out.

Note: Sealed or Open? In a sealed circuit, the system is filled to approx 1 bar pressure and then sealed. Unlike an open-vented system, there is no cistern, so an expansion vessel handles excess water. Sealed systems are more efficient.

More about us

LSA Heating was established with the aim to help people avail quality, prompt and efficient heating, gas and plumbing services. With a workforce of skilled plumbers, gas units experts and heating engineers, we strive to install, renovate and repair diverse household gas, plumbing and heating units.

Headquartered in London, LSA Heating serves the entire London and its surrounding areas. Our liability insurance gives us cover for 2million worth of damages. With our experience of over 30 years, we are equipped with proven methods, practical tools and helpful knowledge to undertake any kind of heating, gas and plumbing work.

With our dedicated and proficient workforce, we are able to meet and exceed our clients’ expectations. Not only providing them the best services at competitive rates, but we also deliver them the results they wish for. Our vision is to deliver quality, impressive upgrades to central heating systems, kitchen, bathrooms, cloak rooms, wet rooms and beyond.

More about our services


Working on boilers, underfloor heating systems, and unvented cylinders, our tradesmen install innumerable central heating systems a year. Designing bespoke heating systems, we provide our clients with exactly what they need.

Our workforce is trained to convert regular boilers into combi boilers to help you reap great benefits. We comply with the most stringent industry standards in all our installation and refurbishment services, thus giving our clients absolute peace of mind.


Our experienced bathroom specialists work closely with our clients to help them achieve the desired high-end, stylish look without spending hefty amounts. We take pride in our trained, skilled tradesmen who can design a custom-built bathroom that is sure to live up to your expectations. From installation to repairs and to refurbishment, we can undertake and complete varied bathroom jobs successfully.
We specialize in:

  • Full bathroom installation
  • Bathroom suite swap
  • Full bathroom refurbishment
  • Disabled bathroom conversion

Gas servicing

At LSA Heating, we undertake gas appliances’ inspection and maintenance jobs for our clients.


Being the core service we offer, plumbing is the foundation of LSA Heating. Whether you want to get a new tap washer installed or find a solution for your leaking kitchen drain, we have got all your needs covered. Offering plumbing services in and around London, we strive to deliver professional, lasting results.

The key aspects of our plumbing services are:

  • Water tanks
  • Waste disposals
  • Pumps
  • Showers
  • Overflows
  • Leaks
  • Hot water issues
  • Tap
  • Toilets

Boiler installations London

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Boiler installers London

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