The Ultimate Guide To Boilers

Boilers are responsible for your home heating and hot water. Since you rely on our boilers on a daily basis, it can be all too easy to take them for granted. But how much do you really know about one of the most essential appliances in your home?

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

Types of boilers

There are three main types of boiler: combi boilers, system boilers and regular boilers. With three types to choose from, picking the right one for your household can be a confusing task. To help you decide which one will be best suited to your home, take a look at the three main types of boilers below:

Combi boiler – A combination or ‘combi’ boiler combines both a high efficiency water heater with a central gearing boiler in one single unit. Combi boilers heat water instantly from the main water supply so you don’t need to wait for the hot water tap to heat up. Because of this, you won’t need a hot or cold water storage tank in your roof space.

Because hot water is delivered at mains pressure from combi boilers, you can also have the added benefit of powerful showers in your property without needing a separate pump.

Best homes for combi boilers?

  • Smaller properties
  • Little or no loft space


System boiler – system boilers are fairly quick and easy to install as the main heating and hot water components are built into the boiler itself. As with combi boilers, there is no need for a tank in the loft with system boilers, since all the major system components are built in.

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).

Best homes for system boilers?

  • Those with more than one bathroom
  • Little or no loft space


Regular boiler – regular boilers (otherwise known as traditional or ‘heat only’ boilers) are most appropriate for homes that already have a conventional heating and hot water system. Regular boilers also require a cold water storage tank in your home’s loft space to feed through to the hot water cylinder. A separate tank is also required to maintain the water levels of your central heating system.

Unlike combi and system boilers, regular boilers cannot cope with high water pressure, making it a good option for properties with an old radiator system and ones that may need to replace their existing boiler.

Best homes for regular boilers?

  • Homes that use a lot of hot water at the same time (large family properties)
  • Areas with low water pressure
  • Those with two or more bathrooms


Combi Boiler

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 (Derby)
  • 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 EfficiencyBoiler efficiency

Installing an energy efficient boiler in your home can help you save hundreds of pounds on your heating bills every year. But how can you tell whether or not your boiler is energy efficient?

The age and type of boiler you have in the home normally contributes to how 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 around £340 a year on your energy bill. If your boiler is older than 15 years, this can 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 usually 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. As of October 2010, only boilers that meet an 88% standard of efficiency can be installed homes. If you’re unsure as to your own boiler’s efficiency, arrange for a home boiler assessment.

Best boilers

Currently, the most popular boiler type in the UK is condensing boilers and by law, all newly fitted central heating boilers are required to be condensing boilers. Condensing boilers come in the three boiler varieties (combi, system and regular). However, new and A-rated condensing boilers now use a third less fuel than older boiler types which help to cut your heating bills (and your carbon footprint) by a third.

They also boast an impressive 90% efficiency rating compared with the poor 60% energy efficiency rating of older boilers. If you’re unsure as to which variety of condensing boiler you would like to install, consult a qualified installer to ensure you choose the most appropriate type for your home’s size and the fuel you use etc. Whichever boiler you currently have in the home, make sure it receives regular servicing. The best boiler is one that is well cared for.

Boiler prices

Depending on the size, type and brand of boiler you are looking to buy, prices can vary from £600 to £2,000 (note that this does not take into account installation costs). Be aware, also, that a high-price boiler will not always guarantee a reliable and high quality boiler.

To get an accurate estimate of current boiler prices in the UK, be sure to 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.

Boiler replacement costs

Over time, old boilers can become unreliable and even pose a threat to you and your family’s safety. For that reason, it’s recommended that you get regular boiler assessments to 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. Depending on the work it may take to replace your existing boiler, you can expect to pay around £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. This is due to extra services provided by your supplier such as boiler cover and other add-ons included in the replacement cost package.


Boiler installation and costs

Whether you choose a local Bristol plumber or choose to buy your boiler directly from the manufacturer or energy supplier, the process of installing a boiler in your home is carried out in a similar way.

First, a contractor will begin by laying down a floor protector to minimise damage to your property. Next, they will check your current boiler for any possible gas or water leaks. After this, your old boiler as well as any water tanks and cylinders will be removed to accommodate a modern boiler system. Once this is complete, the new boiler is fitted and tested for leaks using a compressor. Further checks are carried out, including a ‘gas rate’ analysis to check the performance of the boiler.

Once 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.

Gase SafeGas Safe engineer

A Gas Safe engineer is simply an individual who is legally permitted to work on your boiler or on any other gas appliance that you may have in the home. A Gas Safe accreditation is the ultimate symbol of gas safety in the UK and a qualified boiler installer or servicer 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, make a 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 must 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.


Government boiler scheme

In January 2013, the government launched the free boiler scheme to help reduce energy consumption in the UK and to provide low-income households with grants. The free boiler scheme is part of the ECO (Energy Company Obligation) which was formed in 2012 and will run until 2017. The boiler scheme essentially states that if your boiler is 10 or more years old and you receive a qualifying benefit (see below), you could be entitled to grant funding towards the cost of a new A-rated boiler.

Read through this eligibility checklist to find out if you qualify for a free boiler or insulation grant. Are you in receipt of any of the following?

  • Child tax credit
  • Working tax credit
  • Pension credit
  • Job seekers allowance
  • Universal credit
  • Employment and support allowance


Boiler scrappage scheme and boiler grants

As of March 2010, the UK’s boiler scrappage scheme, which helped homeowners upgrade to a more energy efficient heating system, unfortunately closed. However, homeowners may still be entitled to help with their boiler costs under the ECO scheme as mentioned above.

If you meet the criteria under the ECO boiler scheme, eligible households with an old non-condensing boiler (10 years or more) can qualify for a non-repayable boiler grant. This was set up to give low-income households a helping hand and ensure that more homes throughout the UK can reduce their home heating costs.

Hopefully, this handy guide to all things boiler-related has proved helpful when it comes to the service and maintenance of your own boiler.

If you are in the Bristol area and are considering installing a new boiler this coming winter, or perhaps need some professional advice regarding your current boiler’s efficiency, don’t hesitate to contact the team at Watertite Plumbing & Heating Ltd. Our highly qualified firm of plumbers and heating engineers pride themselves in delivering top quality service every time. Give yourself peace of mind about your boiler today and get in touch with one of our friendly and reliable team members.