The short answer
A building survey reports on the visible parts of the boiler and heating system but does not test or commission them. The surveyor notes the boiler type, age, location and casing condition, the flue, the visible pipework, radiators, controls, cylinders and any cold-water tanks, and flags obvious signs of leaks, corrosion or poor installation. They do not fire up the boiler, test that it heats, or check gas safety — that is the work of a Gas Safe registered engineer. So the survey tells you the system's apparent age and condition and whether there are visible red flags, then recommends a Gas Safe service and safety check where the boiler is old, of uncertain condition, or shows warning signs. An old or end-of-life boiler is a common budget item the survey will highlight.
A boiler is one of the more expensive items in a home, so buyers ask whether the survey covers it. Here is exactly how heating is treated.
Heating check at a glance
- Boiler tested?No — visual only
- NotedType, age, casing, flue, leaks
- RadiatorsVisible condition only
- SpecialistGas Safe registered engineer
- Common flagOld / end-of-life boiler
What the surveyor records about heating
The heating system is inspected visually, from accessible positions. The surveyor identifies the boiler type (combi, system or conventional), notes its apparent age, make where visible, location and the condition of the casing and flue, and looks for obvious problems such as corrosion, staining, leaks, dripping pressure-relief pipes or signs of poor or DIY installation. They record the radiators and their condition, the visible heating pipework, any hot-water cylinder or cold-water storage tank, and the presence of controls and thermostats. For an older conventional system they note tanks in the loft and the cylinder; for a combi they note the single unit. What they cannot do is judge performance — efficiency, output and whether it actually heats the home are not part of a visual survey.
Why the system is not tested
Firing up and testing a gas boiler is regulated work that only a Gas Safe registered engineer may carry out, and it sits outside a building survey's non-intrusive, no-commissioning remit. The surveyor will not turn the system on under test, will not check the gas, and will not certify safety. The split is clear in the table below.
| Item | Building survey | Gas Safe engineer |
|---|---|---|
| Boiler casing & flue | Visual condition, age | Internal service & safety |
| Heating operation | Not tested | Test firing & output |
| Gas soundness | Not checked | Gas tightness test |
| Radiators / controls | Visible condition | Balancing & function |
Indicative split between survey and gas engineer. Source: Gas Safe Register; RICS.
When to get a Gas Safe check
The survey will recommend a Gas Safe service and safety check where the boiler is old, of uncertain age, lacks a recent service record, or shows visible warning signs. This is a sensible follow-up on most older purchases: a registered engineer will service the boiler, test it fires and heats correctly, check gas tightness and flue safety, and tell you whether it is safe, near the end of its life, or due for replacement. Because a new boiler is a significant cost, knowing the system's true state before exchange lets you budget or renegotiate. Ask the seller for past service records and any installation paperwork too — a documented service history is reassuring, and a recent gas safety record (where one exists, such as in a let property) is useful supporting evidence.
Frequently asked questions
Does the surveyor switch the boiler on?
No. A building survey does not fire up or test the heating. The surveyor records the boiler's type, age and visible condition only. Testing and gas safety are the job of a Gas Safe registered engineer, which the report will recommend.
Will the survey tell me if the boiler needs replacing?
It will flag an old or end-of-life boiler and recommend a Gas Safe check, but it cannot confirm performance by sight. A registered engineer can tell you whether the boiler is safe and serviceable or due for replacement.
Are radiators and heating controls checked?
Only visually. The surveyor notes the condition of radiators, visible pipework and the presence of controls and thermostats, but does not test that they heat or function. A heating engineer can confirm performance if there are concerns.
Sources & further reading
Figures on this page are typical UK ranges drawn from published sources and depend on the specific property and survey level. They are guidance, not a quotation.