Combi, system or regular: which boiler is right for your home?
A combi heats water on demand and suits smaller homes with one bathroom. A system or regular boiler suits homes that need hot water in several places at once. The right choice depends on your home, so we look at the job and give you a written price.
- A few quick questions
- No obligation
The three types differ in how they store and deliver hot water. Pick by how many people use hot water at once, how much space you have and what your heating system already looks like.
The three boiler types side by side
Combi boiler
Heats water straight from the mains when you turn on a tap. No tank needed.
- Saves space, as there is no hot water cylinder or loft tank
- Hot water whenever you want it, with no waiting for a tank to heat
- Often simpler pipework in a smaller home
- Can struggle if two taps or showers run at once
- Needs good mains water pressure
- Not ideal for a large household with several bathrooms
System boiler
Heats a separate hot water cylinder and feeds the radiators directly.
- Hot water is ready at several taps at once
- No loft tank needed
- Works well in homes with more than one bathroom
- Needs space for a cylinder
- Once the stored hot water runs out, you wait for it to heat again
Regular boiler
Uses a cylinder and loft tanks. Often found in older homes with an existing traditional system.
- Suits older heating systems with existing tanks
- Hot water at several taps at once
- Can be a straight swap for a similar boiler
- Needs loft space and a cylinder
- More pipework and parts to look after
- Stored hot water can run out
Ask us to price it
Tell us about your home and we work out which type fits, then price it.
- A written price before any work starts
- No obligation to go ahead
- A local installer, not a national call centre
Questions to ask about your home
- How many bathrooms and showers do you have?
- How many people use hot water at the same time?
- Do you have a hot water cylinder or loft tanks now?
- Is there space for a cylinder if you need one?
- Is your water pressure strong at the taps?
- Are you adding a bathroom or extension soon?
When a combi is usually the better fit
A combi tends to suit flats and smaller houses with one bathroom and a few people in the home.
It frees up the cupboard or airing space a cylinder would take. You get hot water on demand, without waiting for a tank to reheat.
If you are replacing an old combi, a new one is often the easiest swap. Your installer can check that your pipework and water pressure suit it.
Choosing a boiler type
Do
- Count the bathrooms and how many people use hot water together
- Check where a cylinder or tank would fit
- Ask for a written price before agreeing to anything
- Compare the type you want with what suits your home
Don't
- Pick a type only because a neighbour has it
- Assume a combi suits every home
- Ignore your water pressure
- Rush into a decision on the day of a breakdown if you can avoid it
When a system or regular boiler makes sense
If your home has two or more bathrooms, or a busy household, stored hot water copes better when several taps run together.
A system boiler is a neat choice if you want to drop the loft tanks. A regular boiler can suit an older home where the existing tanks and pipework are staying.
Switching type can mean extra pipework, so it is worth asking what is involved before you decide.
Common questions about boiler types
Is a combi boiler always cheaper to fit?
Not always. It can mean less pipework and no cylinder, but it depends on your home. We look at the job and give you a written price before any work starts.
Can I swap a regular boiler for a combi?
Often, yes, but it can involve changing pipework and removing tanks. Tell us what you have now and we will say what the job involves in your written price.
Will I get a certificate after a new boiler is fitted?
Read our page on the boiler building regulations certificate to see what it is and why it matters.
Where can I read more about replacement?
Our boiler installation and replacement page explains how a replacement job works, from the first questions to the price.
Jobs like this
Example images of the style of work, not photos of our jobs.
How it works
Get my price- 1
Tell us about the job
A few quick questions about your boiler and what is going on.
- 2
Get your price
A written price before any work starts.
- 3
We do the work
We do the work you agreed.
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Where we work
Aylesbury and the areas around it. Every postcode listed is in our area.
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Want it sorted for you?
Tell us what's going on and we'll price the job.
- A few quick questions
- No obligation