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Boilers Explained All In One Place

Boilers are responsible for your home heating and hot water. Since we rely on our boilers every day, it can be all too easy to take them for granted. But how much do you know about  what is generally the most essential appliance in your home?

To assist you in getting a better understanding of boilers from typical costs, installation, servicing and more, here is our comprehensive guide to boilers.

Types of Boiler

Boilers are generally categorised in to three main types: Combi boilers, System boilers and Regular boilers. Deciding which of the three types of boiler is the right one for your home can be a stressful task, so to help you choose which one will be most suited to you, we've put together an informative guide.

Combi boiler – A combination or Combi boiler combines both a high efficiency water heater with a central heating boiler in one single unit. Combi boilers heat water instantly from the incoming main water supply meaning you have hot water on demand, with next to no waiting time. Because of this, you don’t need a hot or cold water storage tank in your roof space.

With the hot water being delivered at mains pressure through the Combi boiler, you can also benefit from powerful showers in your property without needing an additional pump.

Homes most suited to Combi boilers

  • Smaller properties up to 3 bedrooms

  • Limited loft space

System boiler – system boilers are relatively quick and easy to install as the main heating and hot water components are built into the boiler itself. Although if used along side an existing vented system they will require plenty of dedicated space.

But when used in conjunction with an Unvented hot water cylinder there is no need for additional feed and expansion tanks, making it a more compact system. Also enabling you to benefit from hot water delivered at mains pressure from the cylinder.

System boilers are also incredibly energy efficient and are even compatible with solar water heating systems, which results in a better carbon footprint than other boiler types (and lower energy bills).

Homes most suited to System boilers
  • Limited loft space

  • Households with high simultaneous hot water usage

  • Homes with multiple bathrooms


Regular boiler – regular boilers also known as heat only boilers are most commonly used in homes that already have a conventional heating and hot water system. Regular boilers require a cold water storage tank in your loft space to feed through to the hot water cylinder this will generate the water pressure at the hot water outlets. A separate tank is also required to maintain water levels of your central heating system.

Unlike Combi and System boilers, regular boilers do not operate as a sealed system, making them most suited to existing older installations that may not cope under the high pressures of a sealed system.

Homes most suited to regular boilers
  • Households with high simultaneous hot water usage

  • Homes in areas with low water pressure

  • Homes with multiple bathrooms



Boiler manufacturers

The top and trusted list of boiler manufacturers in the UK include:

  • Alpha Heating Innovation (Kent)

  • Ariston Boilers (Buckinghamshire)

  • BAXI Heating UK (Warwick)

  • BIASI UK Ltd (West Midlands)

  • Buderus (Worcester)

  • Chaffoteaux & Maury (Buckinghamshire)

  • Glow-worm Boilers (Belper)

  • Heatline Boilers (Belper)

  • Ideal Boilers (East Yorkshire)

  • Keston Boilers (Hull)

  • POTTERTON (Warwick)

  • Ravenheat (Leeds)

  • Saunier Duval (Nottingham)

  • Valliant Ltd (Belper)

  • Viessman Ltd (Shropshire)

  • Vokèra Ltd (Colney)

  • Worcester Bosch Group (Worcester)


Boiler efficiency

Installing an energy efficient boiler in your home can help save hundreds of pounds on your heating bills.

How do you know whether or not your boiler is energy efficient?

The age and type of boiler you have normally contributes to how energy efficient it is. The Energy Trust estimates that using an A rated boiler as opposed to a G rated boiler, for example, will save you on average £340 a year on your energy bill.

If your boiler is over 15 years old, this will usually be classed as an old system boiler and will be up to 90% less efficient that modern A rated condensing boilers.

Energy efficiency in boilers is now expressed in a percentage and is rated by the ‘SEDBUK’ system (Seasonal Efficiency of Domestic Boilers in the UK). SEDBUK calculates a boiler’s efficiency by analysing their efficiency in converting fuel into heat. Since October 2010, only boilers that meet an 88% standard of efficiency can be installed in homes. If you’re unsure as to your own boiler’s efficiency, click HERE to arrange a boiler assessment with us today.

Why upgrade to a condensing boiler?

Currently, the most popular boiler type in the UK is a condensing boiler. The law requires all newly fitted central heating boilers, to be condensing boilers.

Condensing boilers come in all three boiler varieties Combi, System and Regular. However, the new and A Arated condensing boilers will use a third less fuel than older boiler types which help to cut your heating bills further by up to a third.

They also boast an impressive 90% efficiency rating compared to the poor 60% energy efficiency rating of older back boilers.

If you’re unsure as to which variety of condensing boiler you would like to install, give us a call or book a Boiler Installation survey by clicking HERE to have a qualified installer help you choose the most appropriate type of boiler to suite your needs.

What ever the boiler you currently have in the home, make sure it receives regular servicing. The best boiler is one that is well cared for.

Cost of a new Boiler

Depending on the specification and brand of boiler you are looking to buy, prices vary from £600 to £2,000 not including installation costs and associated accessories.

To get an accurate estimate of current boiler prices in Nottingham, visit a price comparison site to help you find the best deals. If you are looking for a specific boiler type or brand, contact a boiler manufacturer to find out the most up to date prices and figures for current boiler types.

Cost to replace my boiler?

Over time, old boilers can become unreliable and even pose a health hazard to you and your family. For that reason, it’s recommended that you get regular boiler assessments to let you know when your boiler needs replacing.

If you are looking to replace your current boiler, here is a rundown of the typical costs involved:

  • Be sure to get a boiler replacement quote from your local boiler and heating engineers as they will be able to offer the most competitive rates with the same guarantees. Depending on the work it may take to replace your existing boiler, you can expect to pay in the region of £2,300 for a typical boiler replacement, according to the Energy Trust.

  • If you choose to go directly with your energy supplier when replacing your boiler, you may be faced with costs between £2,500 and £4000, again this is according to the Energy Trust.


What to expect from your boiler installer

Whether you choose a local Heating Engineer in Nottingham or choose to buy your boiler directly from the manufacturer or energy supplier, the process of installing a boiler in your home is generally carried out in the same way.

Firstly, a contractor will begin by laying down a floor protector to minimise damage to your property. Your current boiler and or cylinder installation will then be checked for any possible gas or water leaks. Generally if your current boiler is still in working order now is the ideal opportunity to cleanse the the existing pipework with either a Chemical flush or a Powerflush. After this, your old boiler as well as any water tanks and cylinders will be removed to accommodate the new modern boiler system.

Once this is complete, the new boiler installation is carried out including size alterations to the gas pipework, a route for the new condensate pipework and any updated system controls, for example, timer, programmer, thermostat, smart controls. The system will then be tested for leaks using a compressor.

Performance checks are then carried out, on the boiler including a flue gas analysis, gas rate and gas inlet pressure test to ensurethe boiler installation meets the manufactures requirements. System controls will also be tested to ensure the new installation is operating as it should.

Now your new boiler is set up and safely in place, your installer will present you with a Homeowner Gas Certificate which must be kept safely by you. Before your installer leaves, they will fully explain how to use your new boiler thermostat or programmer and will answer any queries you may have.

Again, as with boiler replacement costs, the costs of installing a new boiler in your property will vary widely depending on certain factors such as the size of your home and whether or not you choose a local engineer or your energy supplier to carry out the installation. Additional fees may be added to any installation done by your energy supplier or boiler manufacturer as part of their service package with its customers.

Gas Safe Engineer

A Gas Safe Engineer is an individual who is legally permitted to work on your boiler or on any other gas appliance that you may have in the home. The Gas Safe accreditation is the ultimate symbol of gas safety in the UK and a qualified boiler installer or boiler service engineer must be on the Gas Safe register to provide these services.

If you are ever unsure as to the authenticity of a Gas safe engineer, always look out for the yellow ‘Gas Safe’ triangle on their ID card. If an engineer does not sport this triangle, they will not be fully qualified to work on a gas appliance and may put you and your family at risk from possible fires and carbon monoxide poisoning as a result of a poorly fitted appliance.


Boiler servicing

Regular and trusted boiler servicing in your home is of vital importance. A faulty or poorly maintained boiler can have fatal consequences for you and your household, since fires and carbon monoxide poisoning can happen as a result of incorrect boiler servicing.

You can arrange for an annual boiler assessment through your local heating engineer for around £70, but prices may vary depending on your location and boiler type. To ensure you are always receiving a safe and proper boiler service, take note of the below checklist:

  • Your boiler must be serviced EVERY year

  • A good boiler service should take at least 30 mins (If this is any shorter, ask why this is the case)

  • Your home should be fitted with a carbon monoxide detector

  • You are entitled to a copy of the written report concerning your boiler maintenance

  • Last and perhaps most important of all, the person assessing your boiler MUST be registered as a Gas Safe Engineer.


Hopefully, this guide to all things boiler-related has proved helpful when it comes to the replacement, service and maintenance of your boiler. If you are in the Nottingham area and considering installing a new boiler, or perhaps need some professional advice regarding your current boilers efficiency, don’t hesitate to contact the team at APJ Lawson Gas Services. Our highly qualified heating engineers pride themselves on delivering top quality service every time.


Give yourself peace of mind about your boiler, call us or book a Boiler Installation survey today.

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