Regular boiler replacement
A regular boiler is also called a conventional or heat-only boiler. The Energy Saving Trust says it works like a system boiler, with a hot water cylinder, but also has two cold-water header tanks, usually up in the roof space [S1].
Who a regular boiler suits
The Energy Saving Trust says [S1]:
- it tends to suit larger homes, or homes with low water pressure;
- it needs space for the tanks;
- hot water pressure can be much lower than cold;
- it is unlikely to suit a flat.
Checkatrade adds that a conventional boiler can still give hot water if the mains pressure drops [S2].
Keeping the cylinder. The Energy Saving Trust says most heat pumps work with a hot water cylinder, so switching to a combi now may mean fitting a cylinder again later to get a heat pump [S1].
What a regular boiler costs
From Checkatrade's UK cost guide (price tables updated March 2026, read 30 September 2026) [S2]:
| Job | Checkatrade figure |
|---|---|
| Conventional boiler (supply and install) | about £3,000 |
| Conventional boiler (supply only, summary table) | £1,500 |
| Regular boiler to combi (supply and install) | about £4,000 |
A regular to combi change takes about 1.5 to 2 days [S2]. These are UK ballpark figures, not Cheltenham prices, and not a quote. The cost guide lists the extras, such as a powerflush, a system filter or new controls.
The rules
- Gas Safe. The HSE says anyone paid to work on gas appliances in a home must be Gas Safe registered [S3]. Check the engineer's ID card and licence number: our FAQ says how.
- Building regulations. An installer registered with a competent person scheme can self-certify the work. gov.uk says they give you a certificate within 8 weeks of finishing [S4].
- Condensing boiler. The Planning Portal says a replacement gas boiler will probably have to be a condensing boiler, unless there is a good reason it cannot be [S5].
- Flue. Planning permission is not normally needed when the work is all inside. An outside flue is normally permitted development if it meets the conditions, but conservation areas and listed buildings have extra rules [S6]. See the area pages for Cheltenham, Gloucester and Tewkesbury.
Get a quote
Request a free quote. We are a quote-matching service, not an installer: with your consent we pass your enquiry to one Gas Safe registered boiler installer.
Frequently asked questions
Is a regular boiler the same as a conventional or heat-only boiler?
Yes. The Energy Saving Trust says these are three names for the same type [S1].
How much does a new regular boiler cost?
Checkatrade's UK guide (updated March 2026) puts a conventional boiler at about £3,000, supply and install [S2].
Sources
- [S1] https://energysavingtrust.org.uk/advice/boilers/, accessed 2026-09-30
- [S2] https://www.checkatrade.com/blog/cost-guides/new-boiler-cost/, accessed 2026-09-30
- [S3] https://www.hse.gov.uk/gas/domestic/faqs.htm, accessed 2026-09-30
- [S4] https://www.gov.uk/building-regulations-approval/use-a-competent-person-scheme, accessed 2026-09-30
- [S5] https://www.planningportal.co.uk/permission/common-projects/boilers-and-heating/building-regulations, accessed 2026-09-30
- [S6] https://www.planningportal.co.uk/permission/common-projects/boilers-and-heating, accessed 2026-09-30