A gas safety check examines every gas appliance, the flues serving them, the ventilation and the installation pipework, and produces a written record. It is a legal requirement for landlords and a sensible precaution for homeowners, particularly when buying a property or after any building work.
Who should have one, and when
- Landlords – annually, as a legal duty. See landlord gas safety certificates.
- Anyone buying a property with gas appliances. A homebuyer survey will note that there is a boiler. It will not tell you whether the flue is intact in the loft void, whether the ventilation has been blocked up, or whether the previous owner’s DIY is safe.
- After any building work, particularly anything affecting walls, lofts, windows or extraction. A new extractor fan, a blocked-up airbrick or a boxed-in flue can all create a problem where none existed, and none of them look like gas work.
- Where appliances have been added or moved by somebody whose competence you cannot establish.
- In an older property where nobody knows the history, which describes a lot of housing stock.
- Where there are symptoms – see below, and act on them rather than waiting for a booked visit.
The warning signs, and what they mean
A gas appliance burning incorrectly frequently gives visual clues before anyone becomes unwell. These are worth knowing:
| Sign | What it suggests |
|---|---|
| Yellow or orange flame instead of crisp blue | Incomplete combustion. The classic visual indicator |
| Sooty or brown staining around an appliance | Combustion products entering the room rather than leaving by the flue |
| Pilot light that keeps going out | Often a flue or ventilation problem rather than a faulty pilot |
| Excessive condensation in the room when the appliance runs | Combustion products in the room – water vapour is one of them |
| Headaches, nausea, dizziness or drowsiness that improve when you leave the house | Possible carbon monoxide exposure. Treat as urgent |
| Several people or pets in the household unwell at once | The pattern that most often identifies CO. Illness that tracks with time spent at home |
Turn appliances off, open doors and windows, get everyone out, and call the National Gas Emergency Service on 0800 111 999. Seek medical advice and tell them you suspect CO exposure – there is a specific blood test. Do not go back in until it has been investigated.
What we check
The same scope as a landlord check, whoever owns the property:
- Every gas appliance, operated and inspected, with combustion analysis where the appliance type allows.
- Flues, along their accessible length, including inspection hatches where they exist. A flue that has separated in a loft void is a serious defect and it is invisible from the room below.
- Terminal positions, against the required clearances to openings, boundaries and surfaces.
- Ventilation provision – whether it exists, whether it is adequate for the appliances, and whether it has been blocked. Blocked airbricks are one of the most common findings.
- Installation pipework, visually, along its accessible route.
- A tightness test on the installation.
- Operating pressures and gas rates against appliance data plates.
- Electrical bonding at the meter.
- Safety devices on every appliance.
You get a written record listing every appliance, what was checked, what was found, and the classification of any defect.
The interaction nobody expects
One finding worth explaining, because it catches people out. Modern homes are much more airtight than they were, and mechanical extraction is much more powerful. A large kitchen extractor running in a sealed room can lower the pressure in that room enough to interfere with a flued gas appliance – in the worst case drawing combustion products back down the flue into the room.
This is why ventilation is assessed as a whole, and why a new extractor hood, replacement windows, a blocked airbrick or newly draught-proofed doors can all create a gas safety issue without anybody touching the gas. It is also why ‘nothing has changed with the boiler’ is not evidence that nothing has changed.
Bought a house with gas appliances and no history? A safety check is a small cost against what it can find.
Questions we get asked about this
Is a gas safety check a legal requirement for homeowners?
No – the annual duty applies to landlords. For an owner-occupier it is a precaution, and a sensible one after buying a property, after building work, or where the history of the appliances is unknown.
How is it different from a boiler service?
The check establishes whether appliances and the installation are safe, across everything gas in the property. A service is manufacturer-specified maintenance on one appliance. They are commonly combined and are not the same.
What if you find something dangerous?
It is classified, explained, and – with your permission – the appliance is turned off and labelled until it is put right. Where something is immediately dangerous and permission is refused, the emergency provider is notified, because at that point it affects more than the person refusing.
Do you check gas fires and cookers too?
Yes – every gas appliance in the property, along with the flues and ventilation serving them. Gas fires in particular are worth checking, because they are used seasonally and the problems develop unnoticed.
How long does it take?
It depends on how many appliances there are and how accessible the flues are. A single boiler is fairly quick; a boiler, a fire and a cooker with a loft flue run takes longer.
Should I have a carbon monoxide alarm?
Yes, in any room with a fuel-burning appliance, sited to the manufacturer’s instructions. Check the replace-by date on the casing – they have a finite life and an expired alarm gives false reassurance, which is worse than none.
What happens when you call
Call and describe it
You speak to an engineer, not a call centre. Most jobs can be narrowed down on the phone.
We look at it properly
A real diagnosis before a price, and a straight answer if it is not worth doing.
A written quote
Itemised, so you can see what you are paying for.
The job, and the paperwork
Certificates where the work needs them, and what will need attention next.
Where we do this work
Across Norwich and the whole of Norfolk. If you are on the edge of the county, call and ask — we will tell you honestly whether we are the right people.
- Norwich
- Wymondham
- Dereham
- Attleborough
- Aylsham
- North Walsham
- Cromer
- Diss
- Loddon
- Long Stratton
- Watton
- King's Lynn
Need this doing?
Call and describe the problem — you will speak to an engineer, not a call centre. Written quotes, no estimates over the phone.