As a homeowner contemplating modernising or installing a boiler system, understanding the necessary process for various installations can be useful. Whether you are upgrading, downgrading or simply replacing your current boiler, be aware that disruptions will occur. However, with appropriate preparation and insight, you can manage these disruptions effectively.
Let’s consider the twelve different boiler installations that you might encounter.
- Like-for-like replacement
- Upgraded boiler
- Downgraded boiler
- Installation of combi boiler
- Installation of heat-only boiler
- Installation of system boiler
- Change from combi to heat-only
- Change from combi to system
- Change from heat-only to system
- Change from heat-only to combi
- Change from system to combi
- Change from system to heat-only
We’ll assume that central heating is already in place. If you’re having a completely new boiler installation where none existed before, it’s likely that there are no central heating radiators in the home. If that job is also being done, it’s a pretty big job, especially in an occupied house. You can expect it to take several days, or even more than a week for a large installation. In this article, we’re not including the time taken to install radiators, as that’s very different for every home.
Now, we’ll go into more detail about what you, the homeowner, can expect in the way of disruption, time taken and access required. We’ll also briefly cover why you might want such an installation, and the benefits it’ll bring.
1. Like-for-like boiler replacement
Why have a like-for-like boiler exchange?
A like for like change would be when you’re swapping a combi for another combi, a heat-only boiler for a heat-only, or a system boiler for another system boiler. Importantly, that would mean the change would be between two boilers with identical or similar specifications.
These replacements are typically carried out when your existing boiler becomes faulty, inefficient or obsolete. The main reason for this type of change is to maintain an effective heating system without changing the type or model. It is by far the most straightforward change, and you might be tempted to perform it to keep costs down – and that’s completely understandable.
However, it’s always worth considering whether a more substantive change would benefit you and your family. If the boiler was included with the house when you moved in, the previous occupants might have had very different needs than you do. For example, they might have been living alone, so would have had very modest hot water needs. They could have had an open fire, and rarely used central heating.
Or it could work the other way – they could have been a large family, whereas you might just be a couple or living on your own. A change from a system to a combi might make sense in such cases. You’ll certainly save money in running costs. It’s not unusual for people to downgrade from a system to a combi but leave the tanks and cylinders in place. As long as you have space to spare, it minimises upheaval, and as long as they (and the pipework) are not corroded, they can be used in the future if you decide to upgrade.
Talk to our team if you’re in doubt – we can assess your needs and do the maths to work out whether you would benefit from an upgrade or a downgrade, in terms of value for money and home valuation, and in the quality of life of you and your family.
What disruption can you expect?
The disruption caused is usually minimal, affecting only the area around the immediate boiler location. It requires limited access to the locale of the boiler and any directly linked pipework, so your daily routine will not be significantly impacted. Engineers will need access to the outside of the building opposite the back of the boiler, as well as the electrical consumer unit (fuse box). There will need to be a clear route of access between the point of entry (front or back door) and the location of the boiler.
How long will it take?
As the procedure is relatively straightforward, it can generally be expected to be completed within a day. Sometimes, it will be completed within a few hours as there can often be very little to change. Potential causes of increased time include:
- Poor access to the boiler
- Pipework inlets and outlets on the boiler being in totally different positions
- Flue being in a different position
- Electrical demands being different
- Boiler being larger or smaller than the original
- Unexpected complications being uncovered during dismantling or inspection
2. Upgrading your boiler
Why upgrade your boiler?
An upgrade is often chosen when homeowners want better efficiency, modern features or more power from their heating system. Here, we’re talking about the same type of boiler being replaced. For example, you are changing a 24kW combi boiler to a 32kW combi boiler.
If you feel like your radiators aren’t getting hot enough, or your boiler is on full all the time just keep itself ticking over, it’s likely that the demands of your household are not being met by the capability of the boiler. Upgrading a boiler can offer a multitude of benefits to the homeowner, so let’s break down some of the primary reasons:
- Improved efficiency: Bigger models operate with significantly higher efficiency when they are doing more work, transforming more of the fuel they consume into heat. This improved efficiency can actually reduce your fuel consumption, leading to lower energy bills. It may seem counterintuitive, but you can think of it in a similar way to driving a car with four people in it, compared to four cars with one person each in them. The one car might be using more fuel, but it’s doing more useful work and is therefore working more efficiently.
- Enhanced safety: Upgrading to a new boiler can also enhance safety. Older boilers may fail to meet current safety standards or could be at higher risk of carbon monoxide leaks.
- Advanced features: Modern boilers often come with advanced features such as smart controls, which allow you to control your heating system remotely from your smartphone or tablet. This lets you adjust the temperature in each room separately, contributing to both comfort and efficiency.
- Increase property value: An upgraded, high-efficiency boiler can also increase the value of the property. Prospective buyers may be attracted to the energy savings and the convenience that comes with a modern, reliable, top-performing heating system. Expect such upgrades to be more appealing, especially in colder regions.
What disruption can you expect?
This installation might cause a slight disruption, particularly if the new boiler’s size or configuration differs from the existing model. In such cases, it could require adjustments of pipework or control sets, requiring access to external areas, under the floorboards, or the loft. Depending on the extent of these modifications, you could experience some disturbance in your everyday activities.
How long will it take?
The installation of an upgraded boiler can take between a day and two days subject to the specifications of the new boiler and the adjustments required. It’s possible the boiler will require changes to the power supply, water inlet or pipework, as well as any changes to thermostats and such like. Time estimates can be made on a case-by-case basis.
3. Downgraded boiler
Why downgrade a boiler?
There are several reasons why a homeowner might consider moving from a larger capacity boiler, such as a 32kW, to a smaller one, like a 24kW model:
- Size of the property: If the home is smaller or well-insulated, or the number of radiators or bathrooms has decreased due to renovations, the existing higher kilowatt (kW) boiler may now be oversized for the needs of the property. Consequently, downgrading to a suitably sized boiler can improve efficiency and reduce energy bills.
- Financial considerations: Smaller boilers often come with a lower upfront cost, both in terms of the purchase price and installation costs. In addition, operating cost over time could be lower as a lesser kW boiler may consume less energy if appropriately sized for the house.
- Reduced energy consumption: An oversized boiler may short-cycle, i.e., turn on and off frequently to maintain the desired temperature, leading to higher energy consumption. Hence, you might want to downgrade to a boiler that’s the correct size for the home, thereby reducing energy consumption.
- Less noise: Smaller boilers are often quieter, which can contribute to a more comfortable living environment, particularly if the boiler is located near bedrooms or living areas.
Always consult with a heating engineer or energy advisor to find the right size boiler for your needs before committing to a downgrade. They can perform a heat load calculation to determine the right boiler for your home based on a variety of factors like house size, number of occupants, radiator count and insulation. Ultimately, the goal is optimum efficiency without sacrificing comfort.
What disruption can you expect?
This process is similar to an upgrade, where some adjustments might be necessary to match the new boiler specifications, such as amending or rearranging pipework. This process might involve mild to moderate upheaval, depending on the adaptability of your existing system to the new boiler.
How long will it take?
This process typically mirrors an upgrade in terms of time and can also take between a day to two days to finish. Time is added due to unforeseen alterations and major differences between the layout of the systems, rather like in a straight swap.
4. Installation of a combi boiler
Why choose a combi boiler?
Homeowners generally opt for a combi boiler to save space, as these boilers combine central heating and hot water supply. They remove the need for separate water tanks or cylinders, so there’s no need for extra hardware and pipework going to and from the loft. The most immediate advantage is that your hot water is on-demand. No hot water is stored anywhere – it just quickly heats up cold mains water automatically once you turn on the hot tap. That means you never “use up” the hot water by running a bath – it’s always available.
What disruption can you expect?
The amount of work depends on whether it’s a fresh installation or you will also be having a system or heat-only setup removed. It’s possible to keep the cylinders even if they are not being used. They’ll be taking up space, but might come in useful if you ever revert to that type of setup. Access will be required to areas like lofts, if tanks exist, and possibly under the floors to accommodate these changes.
How long will it take?
If you’re moving from a traditional system or a system boiler, it may take between one to three days due to the additional processes involved. If it’s a fresh install, connecting to existing radiators and hot water supply, it can usually be done in a day.
5. Installation of a heat-only boiler
Why choose a heat-only boiler?
A heat-only boiler, also known as a traditional or regular boiler, might be the right choice for specific homes based on several reasons.
- Bigger properties: If you have a larger home with multiple bathrooms, a heat-only boiler is often the better choice. With a large hot water tank, these boilers can easily supply multiple bathrooms with water simultaneously, something combi boilers often struggle with.
- Consistent pressure: Heat-only boilers can provide consistent water pressure at multiple points throughout the house. This is because the hot water supply doesn’t depend on the mains pressure as with combi boilers but is instead drawn from the large storage tanks.
- Immersion heater: You can combine gas heating with an electric immersion heater in the cylinder, which can keep your hot water topped up but can also be used with solar panels to provide very cheap and green hot water.
What disruption can you expect?
When installing a heat-only boiler where none existed previously, there is bound to be moderate upheaval. It requires installing a cold water storage tank, usually in the loft, and a hot water cylinder, usually in an airing cupboard, as well as the boiler itself. This process will need access to those spaces and may necessitate some movement of furniture or disruption to household routines.
How long will it take?
Installing a heat-only boiler where none existed before, the procedure could stretch from 2–4 days, given it involves the placement of two separate tanks.
6. Installation of a system boiler
Why choose a system boiler?
Investing in a system boiler can offer various benefits based on your home’s demands. There’s no need for a tank in the loft as the water is fed directly from the mains, using its pressure (which can be a problem in low-pressure areas). There are several reasons why homeowners may want to consider a system boiler:
- Designed for larger homes: System boilers can supply hot water to multiple outlets at once, which is ideal for larger homes with more than one bathroom.
- Space-efficient: Unlike heat-only boilers, system boilers do not require a header tank in the loft because they take their water supply directly from the mains. That can make installation quicker and cheaper than a heat-only setup. The cylinder does take up space, however, so these still need more room than a combi boiler.
- Compatible with solar thermal systems: System boilers can be easily integrated with solar thermal systems for more energy-efficient water heating, making them a sustainable and eco-friendly choice.
- No feed or expansion cistern: System boilers do not require a feed and expansion cistern, which can significantly reduce the risk of frost damage or leakage.
What disruption can you expect?
There will be quite a bit of disruption as pipework will need to run under the floorboards to the cylinder, which is usually upstairs. There’s no need to access the loft, however. Space on the outside of the building behind the boiler will need to be cleared to install the boiler itself.
How long will it take?
Installing a system boiler from scratch will usually take up 2–3 days, thanks to the extensive work that needs to be done under floorboards and passing pipes through walls.
7. Change from combi to heat-only
Why change?
Changing from combi to heat-only means you’ll wake up to hot water, and you’ll have the potential to heat or top up your hot water using electricity, for example with solar. It’s a useful change for growing families, especially if you have extra bathrooms.
What disruption can you expect?
This entails moving from a boiler that provides instant hot water to one that requires separate hot and cold storage tanks. It also necessitates higher upheaval with the need to install two tanks, amend existing pipework, besides needing access to important points in the house like the loft and outside.
How long will it take?
As significant adjustment is necessary with this type of installation (including potentially adding tanks), theo process normally takes 2–3 days, but possibly more.
8. Change from combi to system
Why change?
With this change, you move from immediate hot water supply to a stored hot water system. You can run hot water from multiple taps simultaneously, and you have the option of including an electric heater in the cylinder.
What disruption can you expect?
This requires the removal of the combi boiler and subsequent establishment of a system boiler, requiring the installation of a hot water cylinder, usually upstairs. The job could involve partial lifting of floorboards, or possibly the installation of pipework in the loft.
How long will it take?
This process is relatively involved and can be expected to take around two days, but more time could be required for big jobs or where certain parts are hard to access.
9. Change from heat-only to system
Why change?
This change might be necessary if you need more space in the loft, for example if you’re converting it to be a living space. It’s not advisable if you’re in an area of very low water pressure, however, as the loft tanks give the hot water its pressure.
What disruption can you expect?
This installation involves switching from two water tanks (one for hot water, one for cold) to a single hot water cylinder. This would mean removal of the cold-water storage tank and some modifications to the pipework, therefore causing a fairly significant disruption with access typically required to the loft or wherever the old tanks were stored.
How long will it take?
This type of conversion can generally be expected to take about 2 days due to the removal of the cold water tank and the installation of the new one.
10. Change from heat-only to combi
Why change?
People generally change to combi from heat-only when they have a lower demand for hot water, for example when the kids move out. You might find always-available hot water useful, especially if you don’t feel the need to have a constant supply of hot water, which you might only use rarely. Make sure your local water pressure is high enough to feed hot water at the rate you desire, though.
What disruption can you expect?
A substantial overhaul to the heating system, this switch requires abandoning the water tanks entirely which requires access to the loft or wherever the tanks are situated. This process can cause significant disruption as the combi boiler operates differently to a heat-only boiler, requiring completely different pipework arrangements.
How long will it take?
This process is significantly more labor-intensive due to the need to abandon the water tanks entirely. As such, it may take 2–4 days.
11. Change from system to combi
Why change?
The reasons are usually the same as above (heat-only to combi), although if your system boiler worked fine, your hot mains water pressure is presumably good enough to power a combi boiler too, so that’s good.
What disruption can you expect?
This process involves the removal of the system boiler and its associated hot water cylinder. As a result, significant upheaval should be expected, particularly if the existing pipework needs substantial modification to accommodate the combi system. Access to the hot water cylinder’s location will be needed, as this will need to be removed.
How long will it take?
The time taken depends on how much alteration is required to the existing pipework, but it can typically be completed within 1–3 days.
12. Change from system to heat-only
Why change?
These are similar systems as far as daily use is concerned – that is, your hot water is fed from a tank rather than heated up instantly when you turn on a tap. The main reason you’d make this change is if your water pressure is too low to give your hot water a decent flow. That can sometimes happen, for example if new housing is built nearby that shares your pipework, or if there’s been a change in the location of your local water supply tanks.
What disruption can you expect?
This installation requires removing the system boiler and establishing a heat-only boiler. This process will cause considerable disruption, as it will need the introduction of a cold-water storage tank, usually in the loft, and modify the existing pipework configuration. As such, full house access will generally be needed, including loft and potentially exterior access.
How long will it take?
As this installation involves proper setup of cold-water tanks and reconfiguration of pipework, it could take around 2–4 days to complete this task.