How Long Does It Take to Fit a New Boiler? (2026 Guide)

Here's a realistic guide to how long different boiler fitting jobs take:

• Like-for-like combi boiler swap: 4–6 hours — The quickest job. The new combi goes in the same location as the old one, using existing pipework. Most of our Manchester and Salford jobs are completed in half a day
• System boiler replacement: 5–7 hours — Similar to a combi swap but the hot water cylinder remains. Slightly longer due to additional pipework and cylinder connections
• Back boiler removal and combi installation: 1–2 days — Removing a back boiler behind a gas fire and replacing with a new wall-mounted combi is more complex. Pipework needs routing from a new location and the gas fire surround may need removal
• System to combi conversion: 1–2 days — Removing the hot water cylinder and header tank, re-routing pipework and installing a new combi. More complex than a like-for-like swap
• First-time central heating installation: 2–5 days — Fitting a new boiler and a full central heating system including all radiators and pipework is the most involved job and typically takes multiple days

Several factors can affect how long it takes to get a new boiler fitted:

• Boiler location — Moving the boiler from one wall or room to another requires additional pipework and takes longer than fitting in the same spot
• Flue route — If the new boiler requires a longer or more complex flue route through walls or a roof, this adds time
• Pipework condition — Older or corroded pipework may need sections replaced during the fitting, adding to the overall time
• Sludge and scale — Very dirty systems require a more thorough power flush before the new boiler can be connected, adding 1–2 hours
• Radiator issues — If radiators need balancing or bleeding as part of the recommissioning process, this adds time
• Gas supply — If the existing gas supply isn't adequate for the new boiler's output requirements, the gas meter or supply pipe may need upgrading

When our engineers arrive to fit your new boiler, here's the typical sequence of events:

1. Arrival and setup — Engineers introduce themselves, lay protective sheets and confirm the scope of work
2. System drain down — The central heating system is drained to allow safe removal of the old boiler
3. Old boiler removal — The existing boiler is disconnected from gas, water and electrics, then removed from the property
4. New boiler positioning and mounting — The new boiler is positioned, mounted on the wall and aligned to existing or new pipework
5. Pipework connections — All gas, hot water, cold water and central heating connections are made
6. Flue installation — The new flue is fitted through the wall or roof
7. Chemical flush — The system is flushed with cleaning chemicals to remove any remaining sludge or scale
8. MagnaClean filter fitting — A magnetic filter is fitted to protect the new boiler from future sludge build-up
9. Thermostat installation — The Hive Mini Smart Thermostat is fitted and connected
10. Commissioning and testing — The boiler is fired up, all functions tested and every radiator and hot water outlet checked
11. Engineer handover — We walk you through operating your new boiler and thermostat before leaving

Yes — in many cases we can fit a new boiler same-day or next-day in Manchester, Salford and Greater Manchester. Next Gen Boilers Ltd hold boilers in stock at our Irlam depot, so there's no waiting for deliveries.

For same-day boiler fitting: Contact us before midday. If we have the right boiler in stock and an engineer available, we'll do our best to fit the same day.

For next-day boiler fitting: This is available in most cases across Greater Manchester. Call 07305 687 331 to confirm and book your preferred date.

If you're without heating or hot water due to a boiler breakdown, we prioritise emergency fitting jobs — call us and explain the situation.