Central Heating Cost Calculator
A full system is the boiler plus everything around it. This prices the lot — radiators, pipework, controls and the flush — rather than just the appliance.
Open the calculator →Price a heating system in 30 seconds
5 steps. Covers boiler type, radiator count, whether pipework is new or existing, controls and region.
How this calculator works
A heating quote is really four numbers: the boiler, the radiators, the pipework and the controls. Radiators are priced here at £260 fitted, the middle of the £150–£400 range, because the spread depends on size and whether the drop already exists. Swapping like-for-like on existing tails is the cheap end; moving a radiator to a new wall, or upsizing it because a room was always cold, adds pipework and making good, so it is worth telling the installer which radiators you actually want changed rather than leaving it as a round number.
Pipework is where quotes diverge most. Reusing sound existing pipe keeps a system change close to a boiler swap; a full first-fix means floors up throughout and is a different job entirely — and the making good afterwards is usually excluded, so ask.
On paperwork: boiler work is notifiable under Building Regulations. Your Gas Safe engineer registers it and you should receive a compliance certificate within about 30 days. Keep it — a conveyancer will ask. One thing that quietly moves the total: a full system upgrade is the moment to fit thermostatic radiator valves and a modern programmable or smart control, because doing it while the system is drained costs a fraction of retrofitting later, and it is what lets a new boiler actually run at its rated efficiency. If you are choosing the boiler itself, our best boiler brands guide weighs reliability and parts backing, and where wet underfloor heating is on the table for part of the house, the underfloor heating cost calculator prices that against radiators.
Central heating installation costs (2026)
| Item | Typical 2026 cost | Notes |
|---|---|---|
| Combi boiler (mid-range) | £1,800–£2,800 | Supplied and fitted |
| System boiler + cylinder | £2,500–£3,800 | For multiple bathrooms |
| Regular (heat-only) boiler | £2,200–£3,500 | Traditional tank layout |
| Radiator, per unit fitted | £150–£400 | Size and drop dependent |
| Pipework, per property | £500–£2,000 | Reuse through to full first-fix |
| Smart thermostat | £150–£300 | Zoning and remote control |
| Thermostatic radiator valves | £15–£35 each | Part L expects these |
| Power flush | £300–£700 | Often a warranty condition |
| Magnetic system filter | £80–£150 | Protects the new boiler |
Figures match our central heating installation guide and include VAT at 20%. Making good floors and decoration after a full first-fix is normally excluded — confirm before you sign.
Central heating calculator FAQs
Three to five days for a whole-house system with new pipework and radiators. A straight boiler swap onto sound existing pipework is one day. The variable is the first-fix: lifting floors throughout adds days and considerable making good afterwards.
On an existing system, usually yes, and many manufacturers make it a warranty condition. Sludge from an old system will foul a new heat exchanger quickly. If the system is genuinely clean a chemical flush may be enough — ask the engineer to justify which they are quoting. Whichever you have, insist the system is dosed with inhibitor afterwards and a magnetic filter fitted on the return, because those two cheap steps are what actually keep a new heat exchanger clean and are the usual condition attached to the longer warranties.
Combi for most 1–2 bathroom homes: no cylinder, no tank, hot water on demand. A system boiler with a cylinder is better where two showers might run at once, or where mains pressure is poor — a combi cannot deliver more than the incoming main gives it. It is worth having the installer check your incoming mains flow rate before deciding, since a combi that looks fine on paper can disappoint in a home with a weak main, and that single measurement settles the combi-versus-system question more reliably than bathroom count alone.
Yes. Boiler work falls under Part L and the flue under Part J. Your Gas Safe engineer notifies it through the Gas Safe building regulations scheme and you should receive a compliance certificate within about 30 days. Ask when to expect it, and chase if it does not arrive.
Related cost guides
- Central heating cost guide — full 2026 pricing
- Boiler replacement calculator — price the boiler on its own
- Heating repair calculator — if it is a fault, not a replacement
- Building regs for boilers — notification and certificates
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