Combi vs System vs Regular Boilers — Which Is Right for You?
Choosing the right boiler type is crucial for comfort, efficiency and long-term cost savings. At ARA Services Ltd, our Gas Safe engineers help London homeowners decide whether a combi, system or regular boiler suits their property best. Here’s everything you should know in 2025 — including how to choose the right boiler size for your home.
Boiler Types Explained
Combi Boilers combine heating and hot water in one compact unit — ideal for flats and small homes.
System Boilers use a hot-water cylinder but no cold-water tank, perfect for medium-sized homes with multiple bathrooms.
Regular (Conventional) Boilers rely on both hot and cold tanks — best for larger properties with traditional pipework.
For an idea of how much installation costs might vary, see our guide on boiler installation costs in 2025.
Get Boiler AdviceCombi vs System vs Regular — Quick Comparison
| Feature | Combi Boiler | System Boiler | Regular Boiler |
|---|---|---|---|
| Hot Water Supply | Instant, on demand | Stored in cylinder | Stored in tank |
| Space Needed | Minimal | Medium | High (2 tanks) |
| Best For | Flats & small houses | Families with 2 bathrooms | Large, older properties |
| Efficiency (2025) | 94–96 % | 92–94 % | 90–92 % |
How to Choose the Right Boiler
Consider your household size, water usage and available space. Learn more in How to Choose the Right Size Boiler for Your Home or explore running costs in Gas vs Electric Boilers — Pros, Cons & Costs (2025 Guide).
If your boiler is over 10 years old, consider whether upgrading is worth it — our analysis on high-efficiency boilers shows the potential savings.
And if cost is a concern, you may qualify for financial help — check out boiler installation grants and government schemes available in 2025.
Related Boiler Guides
FAQs
Is a combi boiler cheaper to run?
Yes — it heats water on demand, reducing energy waste for smaller homes.
For more on energy efficiency, see how to save money on heating bills with a new boiler.
Do system boilers work with solar panels?
Yes — they pair well with renewable systems like solar thermal panels and heat pumps.
Learn about hybrid setups through the Gas vs Electric Boilers guide.
Which boiler is best for large homes?
Regular boilers are ideal for large properties with multiple bathrooms and high demand.
Explore the best boiler brands in 2025 for top performance and warranty options.