The ins and outs of choosing a boiler

Issues that might help you to decide that now is the time include:

• You’ve had an engineer in to see your existing boiler and have been told that it’s not going to be cost-effective to repair it, because of the combined costs of parts and labour or the scarcity of necessary spares
  
• If the options for controlling your boiler aren’t enough to adjust your heating the way you want. If there’s no thermostat, or the timer/controller is basic, you can probably cut your bills with a newer set-up. In some cases, you may only need new controls, if the boiler is still up to scratch.
  
• Some older boilers have a “dry cycle” where the boiler remains on, even when the ambient temperature set by the thermostat has been reached – the heat is usually redirected to an “overflow” radiator (commonly found in the bathroom), but means that you’re paying for heat that you’re not really using.
  
• If the boiler has a continuous pilot light (usually these boilers have a window allowing you to check that the flame is on) – burning gas 24h a day and costing you money.
  
• If the boiler is sited on the floor rather than the wall, it’s probably old and inefficient and ripe for replacement.
  
• If the boiler is “G” rated for energy-efficiency, you’ll be able to replace it with something much more efficient that will use less gas. It’s been estimated that with a “G” rated boiler, for every pound you spend on your heating, you’re wasting 30p
  
• If you are planning to sell your home, a new boiler can be a selling point that adds value
  
• If the pilot light burns with a yellow rather than a blue flame, you must call an engineer immediately to get the boiler/gas supply assessed. This is important as the boiler may be malfunctioning dangerously
  
• If there is a bad smell emanating from around the boiler, that could be a sign of a gas leak/malfunctioning boiler. Worse still would be that the boiler is emitting the colourless, odourless carbon monoxide as a by-product of the burning of gas – if you’re feeling listless or getting headaches, take a look here for more information:
  
• If you’ve been keeping track of your energy bills and have discovered that they’re becoming more expensive, even taking into account your supplier price rises, that’s also a sign of an ageing boiler
  
• If the radiators seem to be taking longer to get warm, it could be a fault with the boiler or, once again, a sign of ageing

Despite the initial cost, there’s a good chance that replacing an older, inefficient boiler with a new model, combined with thermostatic radiator valves) will save you energy and money over time. How much depends on many factors, but the Energy Saving Trust has done some calculations that can be found here:

What’s the difference between a new boiler and a replacement boiler?

Another important point to consider is the difference between a new boiler and a replacement boiler. Simply put, a replacement boiler is essentially the same make and a similar (newer) model as your existing boiler. This means that all of the pipe work should be able to be connected up straightforwardly with a minimum of fuss. A new boiler, which is a different type, make or model to your existing unit will probably require extensive revisions to the pipe work and other infrastructure – so you need to budget for this extra burden of parts and labour

All new boilers need to be condensing boilers – compared to older types, these have a larger heat exchanger and use latent heat from the flue that would otherwise escape into the atmosphere). There are three types of condensing boiler: Combination, System and Conventional.  The first of these heats water directly from the cold water main for your hot water supply and has a separate, sealed heating system that circulates hot water from the boiler around the radiators. A system boiler also uses a separate, sealed heating circuit and heats water that’s kept ready for use in a hot water cylinder. A conventional boiler (also called traditional, regular boilers, open vent or heat-only boilers) uses a cylinder and also a water storage tank.

Combi boilers are generally the most efficient, as the hot water is heated on demand, so it’s a responsive system and you only pay for what you use. The fact that there is no storage tank or cylinder saves a considerable amount of space as well as installation time and expense. Some other potential advantages are a lower risk of pipework freezing, as there are less pipes to be installed (but it’s ESSENTIAL to ensure that the condensate pipe from ANY boiler is adequately protected from freezing). These may not be the best option for homes with low water pressure, the need for multiple simultaneous baths/showers (eg larger homes) and for certain types of shower systems.

System boilers can be useful for homes with several bathrooms, as these require a hot water storage cylinder, meaning there’s always enough hot water for simultaneous use of several bath/showers. The pump and expansion vessel are part of the boiler, so a cold water header tank in the loft isn’t necessary and there’s less maintenance to be done.  Other advantages include being able to incorporate solar thermal heating into your heating system. Potential disadvantages are that the (well-insulated) cylinder needs to be sited somewhere convenient – its size dictates how much bathing/showering you can do before it runs out and the boiler has to work to refill the tank it with hot water.

Conventional boilers also tend to be a useful way to heat and provide hot water to larger households. A good deal of space is necessary to accommodate a cylinder and a storage tank and this type of system is feasible generally only if the existing plumbing is already set up for a traditional heating system. These boilers can also be linked up to solar hot water panels. These boilers work well where mains pressure is low, can supply hot water to multiple outlets – as long as the cylinder is full of hot water (so there can be a delay in providing more water if the entire cylinder’s hot water supply is used up at once). Installing such a system from scratch is likely to be expensive as there’s more hardware to be plumbed in.

What’s the right boiler for me?

In general, when deciding what to do when it’s time to pay out for a new/replacement boiler, keep in mind that combi boilers tend to be best for smaller properties with only a single bathroom (and this option is the most compact to install, as there are no additional tanks/cylinders) and cylinder-based boilers (system and conventional) work better where more space for infrastructure is available and there are more bathrooms/rooms that need to be supplied/heated

As a rough guide, you’ll need to reckon on budgeting from £2,500 upwards. Because the installation costs are always going to be the biggest component of the total price, we can’t be more exact without being able to see what needs doing. You can also compare the reliability of various boiler brands (Which? compares these every year, for example). As a company, we recommend Vaillant because we can provide you with an 8-year guarantee (provided you get the boiler serviced every year by an accredited engineer – not necessarily ours) and these are generally regarded as the easiest to access when repairs do become necessary (Note: Worcester- Bosch boilers tend to be slightly favoured overall as a brand, but NOT by installers/engineers who recognise that certain potentially common repairs are much more difficult to undertake than on a Vaillant).

 Tips

Given the points outlined above, the first thing to consider is how different the incoming boiler is from the outgoing – what changes need to be made to accommodate changes in size, pipework and infrastructure. If it’s not a like-for-like replacement, there may be additional costs for installation – but, if chosen wisely, the savings over time can offset these. For example, pipework might need to be added or re-run. Are there any related building works that should be done at the same time (making good the effects of previous leaks, for example)?

Note that there might be government grants for low-income households to access funding for energy efficiency improvements. Sometimes these are provided via your energy company, others might come from central government. You can find information about these here:

https://www.ofgem.gov.uk/environmental-programmes/eco

https://www.ofgem.gov.uk/environmental-programmes/warm-home-discount-whd-scheme

https://www.gov.uk/winter-fuel-payment

https://www.gov.uk/cold-weather-payment

Please feel free to contact us by email or telephone for more information or to book in an assessment and estimate for a new/replacement boiler.