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Your options with a boiler replacement

If you’ve decided that you need a new boiler, the next step is considering what your options are. But a new boiler is a big investment, and you’ll want to get it right. We know how daunting it can be when you’re faced with so many different brands, types and sizes of boilers - not to mention all of the jargon about efficiency and output! So, we’ve put together this guide to help you get a better understanding of what it is you need and want, before you invite an engineer into your home for a survey. So if you’re feeling overwhelmed with your options, this blog’s for you!

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A man looking at different doors.If you’ve read our blogs: Does my boiler need replacing? and 6 signs you need a new boiler. And you’ve decided that you need a new boiler; the next step is considering your options with a boiler replacement.

But a new boiler is a big investment, and you’ll want to get it right.

We know how daunting it can be when you’re faced with so many different brands; types; and sizes of boilers. Not to mention all of the jargon about efficiency and output!

So, we’ve put together this guide to help you to get a better understanding of your options, before you invite an engineer into your home for a survey.

Why are you in the market for a new boiler?

Before you begin your search, it’s a good idea to identify why you’re in the market for a new boiler in the first place.

Has your boiler packed in completely? Or are you trying to resolve a particular heating problem?

There’s lots of reasons why people invest in new boilers.

Finding your ‘why?’ will help The Heating people to understand what you’re hoping to achieve; so that we can make appropriate recommendations for you.

We generally find that there are four main reasons why people are looking for a new boiler. Do any (or a few of these) apply to you?

  1. You’re hoping to replace your boiler with something more energy efficient, to save money and reduce your carbon footprint;
  1. You’re dissatisfied with your current heating system (for example, you regularly run out of hot water);
  1. You have no heating or hot water because your boiler has stopped working and repair is not possible, or economical;
  1. You’ve noticed warning signs that your boiler may be on its last legs, such as:
  • Your boiler is in it’s ‘golden years’
  • Your energy bills have crept up without explanation
  • Replacement parts are hard to find because of the age of your boiler
  • Your heating system isn’t working like it used to
  • You never have enough hot water
  • Your boiler is regularly breaking down
  • Your boiler or radiators are noisy
  • The flame in your boiler has changed from a blue to a yellow colour
  • Your boiler smells odd when it is on
  • You’ve noticed a leak either from your boiler or from pipes
  • Your boiler is not working at all.

If any of the above applies to you; the next step is to think about what you currently have; and what you want to replace it with.

Do you want to swap like for like? Or are you thinking about a totally different type of boiler?

To answer this question, you’ll need to think about factors such as your satisfaction with your current heating and hot water system. And how many parts of your current system need replacing.

Questions to ask yourself about your current set up

Before considering any boilers, you should arm yourself with some key information:

Are you connected to the UK’s gas network?

Question marks by a piece of paper.Approximately 4.3m households are not connected to the UK’s gas network. If this is the case for you, an oil-powered central heating system could be a great alternative to gas for heating your home.

But if you are connected, gas central heating systems are a logical choice.

How many people live in your house?

Are you always squabbling over who’s used all the hot water? If so, it might be that you’ve outgrown your current heating system.

Large families are likely to use lots of hot water, so a heat-only or system boiler might be more appropriate.

Conversely, if you’ve got a smaller family, you might be producing more energy than you need – increasing your bills and generating unnecessary emissions.

In this case, you might be better off with a combi boiler.

How many bathrooms do you have?

If you have several bathrooms that are being used at the same time; then it’s likely you have high demand for hot water.

This suggests that a heat-only or system boiler could be a good option.

Do you have free space, such as a loft or airing cupboard available?

The three different types of boiler (more on these later) all require different amounts of space.

If you have high demand for heat and hot water; and you have a home with a loft and storage space; then a heat-only boiler might be for you.

If you have high demand for heat and hot water at the same time, but you don’t have a loft, then a system boiler could be a better option.

If you have a relatively low demand for hot water and heat at the same time; a combi boiler could be for you.

How many radiators do you have?

A mother and child sat above a radiator.A key factor (but certainly not the only one) in determining the size of boiler you need is the number of radiators you have.

At its simplest, the more radiators you have, the bigger the boiler you will need.

But in general, you want to be choosing the smallest suitable boiler that will offer you the greatest level of economy, so you’re not paying for energy that you don’t need.

The Heating People complete whole house heat loss calculations as standard for all boiler installations; to ensure that you get the perfect size boiler for your needs.

If an engineer wants to determine your boiler size just by counting radiators – RUN! This is completely accurate. The number of radiators is simply a factor that should be borne in mind alongside scientific calculations.

Now that you’ve got an idea about the factors to consider, you are in a better position to determine whether you want a similar replacement, or a whole new system.

Replacing like for like vs a new type of boiler

The first thing to consider is whether you want to replace like for like, or whether you want to take the opportunity to change to a completely different type of boiler system.

If you’re generally happy with what your old boiler offered when it was working well, then a replacement boiler similar to the old one could be a good option.

A replacement boiler is a different (and hopefully more up-to-date) version of the model you already have, which means you’ll already have a lot of the necessary parts in place.

Remember that newer models of the same type of boiler will still be more energy efficient, and may be more powerful than your old one.

Your other option is to get a new boiler, which means that this is the first time you’ve had this specific model, and you’ll need all-new infrastructure installed along with the machine. If so, if this will probably be a bit pricier than a replacement boiler, as you’ll be starting from scratch.

On the flip-side, getting either a new boiler or a replacement boiler will mean that you’re likely to save money on your bills over time. We’re in it for the long-run.

You might like our related blog: 6 top tips for buying a new boiler.

What’s the difference between a condensing and a non-condensing boiler?

A confused woman next to a Vaillant boiler.There’s a common misconception that a ‘condensing boiler’ is a type of boiler, when in fact, it isn’t.

The terms ‘condensing boilers’ and ‘non-condensing boilers’ are confusing because they actually describe the technology within the boiler itself, rather than what sort of boiler it is.

You won’t have to choose between condensing and non-condensing technology, because boilers now use condensing technology as standard.

So whatever type of heating system you opt for, it will be condensing.

Condensing boilers are more energy efficient than their non-condensing counterparts, and can typically extract 90-92% of heat from fuel, compared to 50-80% that a non-condensing boiler can.

This is a good thing because a more efficient boiler will need to burn less fuel to run, and will therefore cost you less on your energy bills.

What are the different types of boiler system?

Diagram of the 3 types of boiler.We pride ourselves on our expertise in finding the heating system that’s right for your home. Although there are many different makes and models of boiler, they all fall into three basic types:

Heat-only or ‘conventional’ boilers

Heat-only or conventional boilers are often thought of as the traditional way of heating a home.

They provide both heating and hot-water with the use of an additional cold-water tank and hot-water cylinder.

Heat-only boilers usually have a large feed tank in an attic or loft. This tank receives cold water from the mains and feeds it down to your boiler.

Once the fuel is ignited, the heat exchanger warms water which is transported to the hot-water cylinder by a pump.

This stored hot-water is then sent to your taps and radiators when you need it.

Heat-only boilers are either sealed or open vented.

In sealed systems, the boiler doesn’t have a feed and expansion tank and is closed to the atmosphere.

Whereas open vented systems are open to atmospheric pressure and do have a feed and expansion tank, helping to accommodate water loss from leakage or evaporation.

The water tank in the loft maintains the right water level whilst a pump circulates the hot water to your home’s radiators.

Advantages of a heat-only boiler

  • Minimal disruption to install if you already have a conventional system in place.
  • Work well in large households with multiple bathrooms.
  • Can supply large amounts of hot water to multiple outlets at the same time.
  • Can be fitted with an additional electrical immersion heater to provide you with back-up hot water in case your boiler ever suffers a breakdown.
  • Easy to integrate with renewable heating systems, such as solar.
  • They are a low pressure system which can benefit older radiators.

Disadvantages of a heat-only boiler

  • Takes up the most space of all 3 boiler options because it requires an external tank and cylinder.
  • They require more third-party components to make the system work. And these component parts generally have a shorter guarantee, often just 12 months, whereas the boiler will often have ten years or more guarantee.
  • Lack of instant hot water – takes time to heat.
  • Generally the least efficient type of boiler because they have the fewest control options.
  • Hot water is stored in a hot water cylinder which will result in heat loss and wasted energy.

The Heating People can work with all manufacturers of boiler, but most frequently install Worcester or ATAG heat-only boilers.

Combination or ‘combi’ boilers

A man thinking a bout a combi boiler.‘Combi’ is short for ‘combination’ boiler because it provides both your heating and hot water from one all-in-one (combined) unit.

Combi boilers are the most popular type of domestic boiler sold in the UK.

They don’t need any external tanks or cylinders because they heat water directly from the mains when you turn on a hot tap.

They typically have two heat exchangers, one for your heating (radiators) and the other for your hot water supply.

The primary heat exchanger focuses on your radiators and carries hot water around your home. The secondary exchanger is for heating the water that comes out of your taps. 

Advantages of combi boilers

  • Space-saving because the boiler itself is the only component part.
  • Never run out of hot water.
  • Can be more efficient due to not having stored water and being compatible with low temperature systems.
  • Fewer third party components required.
  • More control options than a conventional system.

Disadvantages of combi boilers

  • Slower delivery of hot water, so it takes longer to fill a bath.
  • Generally unsuitable for larger homes.
  • Difficult to integrate with renewable energy.
  • In the event of breakdown, both heating and hot water will be off.
  • Not suitable in low pressure water areas.

Read more pros and cons of combi boilers here.

The Heating People’s favourite combi boilers are the Vaillant ecoTEC Exclusive 835 with IQ and the ATAG Economiser iC combi boiler as they both have built in flue gas recovery making them more efficient than other boilers.

System boilers

A woman on a sofa researching on a laptop.System boilers feature aspects of both a heat-only boiler and a combi.

Like a heat-only boiler, a system boiler needs a hot water storage cylinder to heat and store hot water for your taps.

But it doesn’t need a tank in the attic because, like a combi, it takes its water supply directly from the mains.

This cold water is then heated via a heat exchanger, which transfers energy from the gas jets to the water. Once heated, the water is pumped into a large hot water cylinder, where it is stored until required.

Since there is a large store of hot water always available, a steady supply can be maintained even if multiple taps or showers are in use at the same time.

Advantages of system boilers

  • Work well in large households with multiple bathrooms.
  • Can supply large amounts of hot water to multiple outlets at the same time.
  • Don’t require as much space as conventional boilers.
  • Can be fitted with an additional electrical immersion heater to provide you with back-up hot water in case your boiler ever suffers a breakdown.
  • Easy to integrate with renewable heating systems such as solar.
  • Fewer third party components required.
  • Wider range of control options available, compared to conventional boilers.
  • They can be installed to low temperature, high efficiency heating systems.

Disadvantages of system boilers

  • Require more space than a combi boiler.
  • Lack of instant hot water – takes time to heat, although this can be minimised with the correct controllers.
  • Can run out of hot water if controls are not set up properly.

The Heating People generally use ATAG system boilers due to the advanced control options available; high build quality; and relatively low cost.

You might like our related blog: Pros and cons of system boilers.

How much does a boiler replacement cost?

The price of replacing a boiler costs less than you might think. It obviously depends on what you are changing from, and what you are changing to.

But as a rough guide, a boiler replacement costs between £1800-£3500.

How long will it take to replace my boiler?

How long a boiler replacement will take, will vary depending on what work is needed; if your boiler is moving location; or if you have a like-for-like boiler swap. But as a guide, it usually takes between 1-3 days.

Final thoughts…

We hope that you’ve found this blog helpful.

If you’re thinking that it might be time to say goodbye to the old, and hello to the new, contact us today to book your free survey.


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