Choosing a new boiler, Boiler Buying Guide

1. Combination boilers

Combination (Combi) boilers are now the most popular boiler types in the UK. They are small and convenient, fit into cupboards, under kitchen counters or other alcoves. The combi boiler is a “smart boiler”; it warms up watter directly from the mains and there is no waiting time. Your hot water will be endless.

In terms of usage, they are more economical than other boilers as combi boilers do not use a hot water tank or cylander to heat up first. Additionally, combination boilers don’t let the same water go cold, so you don’t have to re-heat the water when you have not used it.

However, the reason some may choose another boiler with a tank and cylinder, is because if your home has multiple hot water outputs at the same time, a combination boiler may not be able to keep up with the demand so your hot shower may suddenly turn cold if hot water is being used at multiple location in the house.

Saying that, Speedy Gas recommends combination boilers above all. Vaillant boilers and Worcester Bosch boilers are probably the highest specification boilers at very convenient costs. We will help you choose the right boiler for your home to avoid hot water issues like this.

If you live in a 1-3 bed house or flat, without several bathrooms, or are short for space to fit a tank, then a combination boiler will be the right choice for you.

2. Sealed system boilers (unvented)

A system boiler aka,”closed or sealed system boilers” work solely on the basis of stored hot water, ready to feed. You will need to have some more space for an system boiler installation to fit the hot water storage tank and airing cupboard.

Despite this added space, a system boiler does not need as much space as an open vent or heating only boiler, which also needs a second boiler in the loft.

The benefit of a system boiler installation is you can run hot water from many points at one time, without any effect on your hot water. You will also get good hot water pressure.

Is this boiler for me?

A system boiler is a good selection for a large home or family with a lot of hot water needs, which would not be suitable with only a combination boiler. You will, of course, have to have the space to build in an airing cupboard and fit the tank.

An additional downside is the initial waiting time for the tank to warm up. But saying that, there are many solutions for this such as timed thermostats and automated systems.

3. Open vent and open vent sealed system boilers

The open vent boiler is what many homes currently have (if you have not replaced it with a Sealed System or Combi Boiler in the last few years).

This is simply a heating system which requires 2 tanks, one in the loft of the house and another in the airing cupboard. So we are talking about a space guzzler.

The way it works is one tank pulls water from the mains and then supplies and feeds the storage cylinder which is heated by the boiler.

Multiple showers, taps and other hot water outputs can be run at the same time. But beware as this open vent boiler system will require time to heat up.

Many people switch from an open vent boiler system to a sealed system oiler (above). This is a relatively cheap transition and will also remove the tank from your loft.

Is this boiler for me?

If your budget and home size allows it, we recommend switching to a combination boiler. But if a combi boiler does not meet your homes’ requirements, then the most cost-effective method is to simple swap over to a Sealed System Boiler (Number 2 above). You will save space and have plenty of hot water.

4. How much will a new boiler cost?

Boiler installation costs can vary depending on the type of boiler you have installed and what replacement boiler you choose. A good gas boiler will cost about £1000, or even cheaper if you buy from companies like Speedy Gas, who get the sale direct from the manufacturer. You can check out our page on boiler installation prices or call us directly.

The one major unknown is really the installation costs. The actual labour on a good plumber in London will determine the price. Every home is different, every client has new specifications and new gas or water lines may need to be run, removal of old tanks etc.

Boiler costs in London have gone up over the last 20 years, but in the last 5 years we have seen a marked drop as the top companies such as Vaillant, Worcester Bosch and others get more competitive.

All in our benefit!

For precise costs and prices on a boiler installation, give us a call on 020 8123 9211 and we will give you the figures.

Good heating!

You may also be interested in our page: Vaillant boiler installation