A guide to new boiler installation

Replacing a boiler is one of the larger things you will pay for in a house, and most people do it rarely enough never to become confident about it. Here is the shape of a job done properly.

1. The survey

Anyone quoting should look at the property, not just ask how many bedrooms. They need the radiators, the bathrooms, the existing system, the flue route and your incoming water flow rate.

A quote given over the phone without any of that is a guess.

2. The quote

It should name the boiler model, state the warranty, and be a fixed price. Vague quotes with day rates and "materials extra" are where jobs grow.

Ask what is included: system flush, magnetic filter, new controls, removal of the old unit, and making good afterwards.

3. The day itself

Floors and carpets protected first. Old boiler drained, disconnected and removed. New unit mounted, connected, flue fitted. System flushed and filter installed. Then filling, pressurising and balancing.

Most straight swaps are one day. Conversions take two or three.

4. Before they leave

• The system balanced, so far radiators heat like near ones
• Controls explained to you, not just left on the wall
• The warranty registered with the manufacturer
• Paperwork handed over, including the Building Regulations notification

Questions worth asking

• How did you arrive at this size?
• Is a flush and filter included?
• Who registers the warranty?
• What happens if something fails next winter?

The answers tell you a great deal about which quote is actually the cheapest.