One of the most common questions we get is how long the installation will take and how much disruption to expect. Here's a realistic guide.
Like-for-like combi replacement (most common)
Replacing an existing combi boiler in the same location: typically 6–8 hours for an experienced engineer. Most completeable in a single working day. You'll have no heating or hot water during the work — plan accordingly if you have young children or elderly occupants.
Combi replacement with additional work
If we're fitting a new flue position, adding a magnetic filter, or running new pipework: 1–2 days.
Switching from heat-only to combi
Removing the cylinder, removing the loft tank, running new pipework, fitting the new boiler: 1.5–2.5 days typically.
Full system replacement (new boiler + all radiators)
2–5 days depending on the number of radiators and complexity of pipework.
What happens to your hot water and heating
For a standard installation, you'll be without heating and hot water from when the engineer starts to when commissioning is complete — typically most of one day. We'll ensure you have hot water before we leave for the evening if working across two days.
Planning tip
Book winter installations in advance — our diary fills up quickly from September onwards. Summer installations are typically easier to schedule at short notice.