New Boiler Glasgow: Combi Installs for Flats

Glasgow has a higher share of flats than any other council area in Scotland: 68.5% of households at the 2022 census. That makes a compact combi in a kitchen cupboard the most common new boiler in the city. The questions that decide the price are mostly about where the flue goes and how dirty the old system is.

Glasgow at a glance

Homes that are flats: 68.5% of Glasgow households live in a flat, maisonette or apartment, the highest share of any Scottish council area (34.4% nationally). Detached houses are just 5.1%. Source
How homes are heated: 75.3% of Glasgow households use mains gas central heating and 12.6% electric (about 37,100 homes). 3.3% have no central heating and 1.1% use a district or communal network. Oil heats 183 households. Source
Water hardness: Very soft. Scottish Water's 2025 results for the Milngavie M3 zone, which serves central Glasgow, show a mean conductivity of just 55 µS/cm, the lowest of Scotland's four largest cities. The Drinking Water Quality Regulator says most Scottish water is soft. Source
Age of homes: Only 57% of Glasgow dwellings were built after 1945, joint lowest with Edinburgh (72% across Scotland). Source
Energy ratings: 65% of homes in Glasgow were rated EPC A, B or C (SAP 2012) in 2022 to 2024, so about 35% were D or below. The Scottish average was 55%. Source

Flue positions

If the new combi can use the same flue route as the old boiler, the job is usually done in a day. If the flue has to move, it must meet clearance rules from windows, doors and neighbouring buildings, which can be tight in a back court. In conservation areas such as Hyndland, Pollokshields or the Park area, avoid new flues on the street side where possible.

Cleaning the old system

A new boiler connected to sludgy radiators will soon be blocked. Make sure the quote includes a chemical or power flush, a magnetic filter and inhibitor. With water as soft as Glasgow's, a scale reducer is rarely needed, so do not pay extra for one.

Sizing

Many Glasgow flats are smaller than they feel. Households here were among the least likely in Scotland to have three or more bedrooms, according to the Scottish House Condition Survey. An installer should size the boiler for your hot water flow and heat loss, not simply fit the largest model.

Glasgow homes and what they need

Sandstone tenement flats

Swapping an old back boiler behind a gas fire for a combi is a common upgrade. Ask for the old flue to be sealed and the fireplace made safe.

Four-in-a-block and cottage flats

Check the gas pipe from the meter is large enough for a modern combi; some need upgrading.

Suburban semis and bungalows

Houses with two bathrooms may suit a system boiler and cylinder, which also leaves the door open to a heat pump later.

Areas covered

Engineers who cover Glasgow work across areas including Partick, Dennistoun, Shawlands, Hyndland, Govan, Maryhill, Pollokshields, Cathcart, Bearsden and Rutherglen.

View Glasgow on Google Maps

Questions people in Glasgow ask

Can I get a grant for a new gas boiler?

The Home Energy Scotland Grant and Loan does not fund like-for-like gas boilers. Households on lower incomes can ask Home Energy Scotland about Warmer Homes Scotland, which can fund heating upgrades.

How much does it cost?

See our new boiler cost guide for typical UK prices by boiler type. Compare at least three written quotes for the same scope of work.

Will I need to move out during the work?

No. A straight combi swap in a flat usually leaves you without heating and hot water for a day or two at most.

Sources

Also nearby: Boiler installation in Edinburgh, Boiler installation in Dundee

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