How much does a new boiler cost in Teesside? (2026)

Price by house, not by postcode

The honest way to read boiler pricing is by what the house asks for. A two-bed Thornaby terrace with a modern combi in the kitchen is the cheapest job on the list: like-for-like, one day, £1,800 to £2,600 with a mid-range appliance. A three-bed Acklam or Fairfield semi with a system boiler, a cylinder in the airing cupboard and tanks in the loft is a conversion, and the extra labour of stripping tanks, capping feeds and making good is what takes it to £2,600 to £4,200. A 1960s Berwick Hills or Redcar house with a back boiler behind the gas fire is the biggest job of the three, because the fire comes out, the hearth and flue are reworked, the gas run is usually upgraded and the boiler moves entirely. Larger houses in Yarm, Wynyard and Eaglescliffe often should not go combi at all, and a system boiler with an unvented cylinder at £3,200 to £5,500 buys hot water that survives two showers at once.

What moves the number

• Brand and warranty: the same output can vary by £600 between a budget appliance with a 5 year warranty and a premium one with 10 to 12 years. Parts availability locally matters more than the badge.
• Output and hot water demand: sized from heat loss and outlets, not from what happened to be there before. Oversizing costs money twice, once to buy and again in short cycling.
• Gas supply: older houses often need the run upgrading to 22mm, adding £150 to £400 depending on route and floor construction.
• Flue route: a horizontal flue through a cavity wall is cheap. Vertical flues, long runs through loft space or scaffolding for a high terrace gable are not.
• Relocation: moving a boiler from bedroom cupboard to kitchen adds a day, new pipework and making good, typically £400 to £900.
• System condition: a chemical clean and inhibitor is included on a decent quote; a power flush at £350 to £600 is extra where sludge demands it.
• Controls: a smart or programmable thermostat and zoning add £150 to £450, and usually pay back in fuel.

Conversion or straight swap

If you already have a combi that works for the household, swapping it is the value option, and the money is better spent on a longer warranty and better controls than on changing the system type. Converting a vented system to a combi frees up a cupboard and the loft tanks, which is why it appeals, but it is the wrong move for a busy family bathroom-plus-en-suite house, because a single combi cannot serve two showers well no matter what its output claims. The other direction, keeping a cylinder and fitting a system boiler, is quietly the right answer in more Teesside houses than it gets chosen in, especially where a future heat pump is on the horizon and a cylinder will be needed anyway.

Hard water, sludge and the local premium

Teesside water is hard enough to matter. Scale on a combi's plate heat exchanger is the most common reason for hot water that goes lukewarm when the tap is opened fully, and it can shorten an appliance's life by years. A scale reducer at £60 to £150 on the mains during the install is one of the cheapest sensible additions on any quote here. Sludge is the other: decades of unprotected steel radiators, particularly in the pre-1990 estates, mean many systems need cleaning properly before a new boiler goes on, and every new install should leave with inhibitor dosed and a magnetic filter fitted.

How to compare two quotes fairly

Put them side by side and check the same six lines: appliance make, model and output; warranty years and who registers it; gas pipe work included or excluded; system clean and filter; controls supplied; and paperwork, meaning commissioning record, building control notification and warranty registration. Cheap quotes usually get cheap by dropping the gas run, the filter or the flush, and none of those are optional in reality. A verbal price over the phone for a boiler nobody has seen is not a quote.

Should the replacement even be gas

It is a fair question in 2026, with grants available for heat pumps and gas prices where they are. Sometimes the answer is yes and sometimes it is not, and it turns on insulation, radiator sizes and space for a cylinder rather than on ideology. The boiler versus heat pump guide works through it with running costs, and the replacement page covers what a gas job includes if you land there.