Boiler Types: Combi, System & Regular
Combi, system and regular boilers explained in plain English, and how to choose the right type for your home.
- Last reviewed: July 2026
- Reading time: 5 minutes
Key takeaway
Combi boilers heat water on demand and suit smaller homes; system and regular boilers store hot water and suit larger homes with several bathrooms.
Combi boilers
A combi (combination) boiler heats your hot water on demand, straight from the mains, without needing a separate hot water cylinder or tank. This makes it compact and a popular choice for smaller homes and flats. The main thing to consider is that hot water can be shared if several taps are running at once.
System & regular boilers
System and regular (conventional) boilers store hot water in a cylinder, so they can supply several bathrooms at the same time without a drop in pressure. This makes them well suited to larger homes with higher hot water demand. A regular boiler also uses a cold water tank, usually in the loft.
Choosing the right type
- Combi: compact, hot water on demand, ideal for smaller homes
- System: stores hot water, good for homes with several bathrooms
- Regular: suits homes with a traditional heating setup
Which is right for your home?
The best type depends on the size of your home, how many bathrooms you have and how much hot water you use at once. During your free assessment we look at your property and how you live, then recommend the boiler that will suit you best — with no pressure to choose a bigger system than you need.
- Matched to your home
- Expert recommendation
- No pushy upsell
Frequently asked questions
What is a combi boiler?
A combi boiler heats your hot water on demand, straight from the mains, without needing a separate cylinder or tank. It is compact and popular for smaller homes and flats.
Which boiler is best for a larger home?
System and regular boilers store hot water in a cylinder, so they can supply several bathrooms at once without a drop in pressure — making them well suited to larger homes with higher hot water demand.
How do I know which type I need?
It depends on the size of your home, how many bathrooms you have and how much hot water you use at once. During your free assessment we recommend the type that suits you best.
Was this guide helpful?
Your feedback helps us improve our guides.
Last reviewed: July 2026 · Reviewed by: Warmr Heating Team