- Area
- Greater London
- Postcode district
- DA14
- Nation
- England
- Guide price
- From £10,650 inc VAT
- Survey
- Free for installation enquiries
What to know about replacing a gas boiler with a heat pump in Sidcup
The question for a Sidcup home is rarely whether a heat pump can work, but what needs to change to make it work well: radiator sizes, pipework, controls and where the unit goes.
Installers in Sidcup take out the old boiler and flue and seal the wall opening as part of the job. Semi-detached and terraced houses in Sidcup often have an airing cupboard that can be reused for a heat pump cylinder.
Moving from mains gas to a heat pump means finding cylinder space, deciding what happens to the gas supply and comparing running costs on realistic assumptions.
- Households ready to give up gas entirely and drop the standing charge
- Combi owners who can find space for a hot water cylinder
- Boilers that are old, unreliable or due for replacement
What's included
- Free survey with heat loss calculation and cylinder siting
- Heat pump cylinder, outdoor unit and weather compensation controls
- Commissioning, MCS certificate and grant application in England and Wales where eligible
- Removal of the gas boiler, flue and any loft tanks
- System flush and radiator upgrades where the design calls for them
Rear gardens and side returns in Sidcup usually offer a sensible spot for the outdoor unit, checked for airflow and neighbours.
Grants and rules for heat pumps in England
In England the Boiler Upgrade Scheme gives £7,500 towards an air source heat pump (£9,000 if it replaces oil or LPG, from 21 July 2026 to 31 March 2027), and since 28 April 2026 a valid EPC is no longer needed. The grant is applied for by the MCS-certified installer and shown as a deduction on your Sidcup quote.
There is no VAT on installing a heat pump anywhere in the UK until 31 March 2027. In England most houses can have an air source heat pump under permitted development, provided the unit meets the MCS noise and siting standards; the old 1 m boundary limit was removed on 29 May 2025. We flag listed buildings, flats and sensitive conservation-area positions at survey.
What to budget for replacing a gas boiler with a heat pump in Sidcup
Here are typical prices for replacing a gas boiler with a heat pump in Greater London, installed and including VAT. Use the guide price tool for a figure based on your home, then a survey confirms it in writing.
| Home | Typical size | Installed guide price | After £7,500 grant |
|---|---|---|---|
| 1–2 bedroom flat or small terrace | 4–5 kW | £10,650–£14,000 | £3,150–£6,500 |
| 2–3 bedroom terrace or semi | 5–7 kW | £11,750–£15,100 | £4,250–£7,600 |
| 3 bedroom semi or small detached | 6–9 kW | £13,450–£17,350 | £5,950–£9,850 |
| 4 bedroom detached | 8–12 kW | £15,700–£20,150 | £8,200–£12,650 |
| 5+ bedroom or larger older house | 11–16 kW | £18,500–£25,200 | £11,000–£17,700 |
Installed, inc VAT: unit, cylinder, controls, minor pipework and commissioning.
How long is the heating season in Sidcup?
On the shortest day Sidcup gets about 7 hours 50 minutes of daylight, and the winter sun reaches only around 15° above the horizon at noon. Winters this far south are milder than in most of the UK, which helps a heat pump run at low flow temperatures for much of the season.
The steps for replacing a gas boiler with a heat pump in Sidcup
- Tell us about your home: postcode, property type and current heating.
- We book a survey in Sidcup; the surveyor measures rooms, windows and radiators and looks at cylinder space.
- The design and quote arrive in writing, including radiator changes and the outdoor unit position.
- On installation days the old system is removed and the new one fitted and filled.
- We commission the heat pump, show you the controls and register the installation.
Replacing a gas boiler with a heat pump in Sidcup: questions
How long does a heat pump survey take in Sidcup?
A home survey in Sidcup usually takes one to two hours. The surveyor measures every heated room, checks windows, walls and radiators, and looks at where the outdoor unit and cylinder can go.
Do you cover Chislehurst as well as Sidcup?
Yes. We arrange surveys and installation in Chislehurst, which is about 2 miles west of Sidcup, and across Greater London.
Where would the outdoor unit go on a Sidcup house?
Usually at the side or rear, on a level base with space around it for airflow and servicing, away from bedroom windows where possible. The surveyor checks positions at your Sidcup home.
Can a heat pump replace a combi boiler?
Yes, but you need room for a hot water cylinder, because heat pumps store hot water rather than heating it on demand. Most homes find a space in a cupboard, utility room, garage or under the stairs, and compact or combined indoor units help where space is tight. The survey measures the options first, so you know where everything will go before you accept the quote.
Will my hot water run out with a heat pump?
Not if the cylinder is sized properly for your household. The survey asks how many people live in the home, how many bathrooms you have and whether you prefer baths or showers, then sizes the cylinder to suit. The heat pump reheats the cylinder on a schedule, often overnight and again during the day, and an immersion heater acts as a backup.