Combi vs System Boilers: Which Should You Choose?

Written by

Embassy Gas

in

Introduction

Choosing the right boiler for your home in Bordon can feel overwhelming. Whether you live in a cottage on the edge of Whitehill or a modern house near Alton, understanding the differences between combi and system boilers will help you pick a heating solution that suits your household’s needs and budget.

What Are Combi and System Boilers?

Combi Boilers

Combination (combi) boilers provide heating and hot water directly from one unit. They heat water on demand, eliminating the need for a separate cylinder or tank. This makes them compact, energy-efficient and a popular choice for smaller homes in GU35 areas like Bordon and Liphook.

System Boilers

System boilers require a cylinder to store hot water but do not need a loft tank. They are ideally suited to households with multiple bathrooms, where two or more taps might be running simultaneously in Farnham or Petersfield properties.

Key Differences at a Glance

  • Space requirements: Combi boilers are compact; system boilers need a cylinder, usually in an airing cupboard.
  • Water pressure: Combi units rely on mains pressure. System boilers deliver good pressure if fitted with a suitable cylinder.
  • Hot water flow: Combi boilers supply hot water on demand; system boilers store hot water ready for use.
  • Installation cost: Combi boilers often cost less to install; system boilers can be pricier due to cylinder installation.
  • Household size: Small homes may favour combi boilers; larger properties with multiple bathrooms often suit system boilers better.

Advantages and Disadvantages

Combi Boilers

  • Pros:
    • Space-saving design—perfect for Bordon flats or townhouses.
    • No need for separate tanks—reduces heat loss.
    • Quick hot water delivery without a cylinder standby loss.
  • Cons:
    • Hot water flow may drop if multiple outlets are used.
    • Not ideal for homes with more than two bathrooms (e.g., large properties in Alton or Hindhead).
    • Dependent on mains pressure—may require a pump upgrade in some GU35 areas.

System Boilers

  • Pros:
    • Stable water pressure—ideal for filling power showers.
    • Can supply hot water to multiple taps simultaneously in Liss or Grayshott homes.
    • Cylinder allows stored hot water during peak periods.
  • Cons:
    • Takes up more space—cylinder needed, usually in an airing cupboard.
    • Higher installation costs compared to combi boilers.
    • Standby heat loss from the cylinder, unless you choose an insulated model.

Which Boiler Suits Your Bordon Home?

When making your decision, consider the following factors:

  • Household size: A family of four in a Farnham home with two bathrooms might find a system boiler more reliable during morning rush hour.
  • Space availability: Flats and smaller houses in Bordon or Alton benefit from the compact combi boiler design.
  • Water usage patterns: If you run multiple showers at once, a system boiler’s stored hot water can cope better.
  • Budget: Combi boilers often have lower upfront costs, but running costs depend on usage. System boilers may cost more to install but deliver stable output.
  • Future-proofing: Planning a home extension in Petersfield? A system boiler allows for easy cylinder capacity upgrades.

Installation and Servicing Considerations

For a smooth setup, always use a qualified Gas Safe engineer. At Embassy Gas, we specialise in both boiler installations and boiler servicing across Bordon, Whitehill and surrounding GU35 areas.

Pre-Installation Checklist

  • Assess available space for a boiler and cylinder.
  • Check water pressure—particularly for combi boilers.
  • Review existing pipework and radiators for compatibility.
  • Obtain quotes and certifications from a Gas Safe engineer.

Maintenance Tips

  • Carry out annual servicing to maintain efficiency.
  • Bleed radiators regularly to avoid cold spots.
  • Monitor pressure levels and top up if needed.
  • Consider adding boiler cover to protect against unexpected heating breakdowns.

Frequently Asked Questions

1. Can I replace my old boiler with a combi?

Yes. If your property in Liphook or Farnham has adequate mains pressure and you don’t need simultaneous hot water in multiple bathrooms, a combi is a space-saving upgrade.

2. How long does a system boiler cylinder last?

With proper maintenance, a well-insulated cylinder can last 10–15 years. Ensure annual checks to prevent corrosion and heat loss.

3. Which boiler is more energy-efficient?

Both types can achieve high efficiency (90%+). Efficiency depends on usage patterns: combi boilers reduce standby losses, while system boilers avoid flow rate drops.

4. Do I need planning permission for a new boiler?

Generally, boiler replacements and installations fall under permitted development, but always check with your local council in Bordon or Petersfield.

Call to Action

If you need help choosing or installing a new boiler, our local Gas Safe engineers are here to guide you. Call us on (01420) 558993 or book online at embassygas.com/book.

Written by Embassy Gas — your local heating experts covering Bordon, Alton, Liphook, Farnham and surrounding areas.

More posts