These notes explain the options we discuss when advising on a replacement boiler. The right choice depends on your existing heating system, the space available and how much hot water you need at the same time.
Your existing system
A regular heat-only system commonly has a hot water cylinder and feed/storage tanks in the loft. A system boiler works with a hot water cylinder and a sealed heating circuit, without the heating feed-and-expansion tank in the loft. Suitable system design and water treatment help protect pipework and radiators.
A cylinder system can provide stored hot water for busy households. Where fitted, an immersion heater can offer a separate way of heating the cylinder if the boiler is unavailable. In warmer weather the hot water can be programmed separately from room heating.
Renewable and Solar Water Heating
If you wish to look into Heat Pumps and/or Solar Water power you will generally require a large hot water cylinder which basically out-does Combi Boilers only advantage of removing the existing hot water cylinder, which was first designed for Landlords to utilise the generations old “airing cupboard” and incorporate the space into a rented room!
What a combi boiler does
A combi heats water when a hot tap is opened, rather than using a separate hot water cylinder. Removing storage tanks can free space in a flat or smaller house. The boiler still needs suitable space, fuel, mains-water supply and drainage.
A combi can suit a home with modest simultaneous hot water demand. If several outlets or showers need hot water together, a regular or system boiler and cylinder may be more suitable. We assess demand and the incoming water supply before recommending the type and output.
Changing from a regular or system boiler
A general refurbishment is often a convenient time to change the system, provided the existing boiler is working safely. Conversion can require new pipes, access beneath floors and openings in walls. Additional radiators and changes to the heating layout also affect the work and the price.
Condensing boilers
Modern condensing boilers recover heat from the flue gases. They need a suitable condensate drain; if one cannot be reached in the existing position, relocation may be needed. We consider this during the survey rather than treating it as an unexpected extra.
Costs and warranties
Installation prices are agreed after a site visit, taking account of the boiler, fuel supply, existing pipework, conversion work and making good. Please use our current rates page for servicing and call us for an installation quotation. We can explain standard and extended warranty options and servicing requirements.
Is a combi right for you?
A smaller home with limited storage space may benefit from a combi. A larger home or one with high simultaneous hot water demand may be better served by a cylinder system. We explain the pros and cons so you can choose a system suited to your home, rather than changing type automatically.