The gas duty is the oldest and least ambiguous of the landlord compliance obligations, and it is still the one most likely to leave a flat unlettable on the day a tenancy is due to start. Not because the rule is complicated — it is not — but because the check depends on access, and access in a Central London block depends on other people.
What the law requires
Under the Gas Safety (Installation and Use) Regulations 1998, landlords must have a gas safety check carried out annually on the gas appliances and flues they are responsible for, by a Gas Safe registered engineer. The engineer produces a record — the document everyone calls a gas safety certificate, or CP12 out of habit. The landlord must keep it and must give a copy to the tenant, and new tenants should receive it at the start of the tenancy.
There are statutory periods attached to issuing the record to tenants and to the arrangements around the annual cycle. We are not printing those numbers here, because they are precisely the kind of detail that gets misquoted and then relied on. Confirm the current periods with government guidance or your solicitor. The practical rule is simpler: do the check before it expires, and hand the record over immediately rather than when asked.
Only a Gas Safe registered engineer may carry out the check. This is not a formality you can have covered by a general handyman, and it is not something a plumber without gas registration can sign. If you are having other work done, our plumbing call-out starts from £80 excluding VAT — but gas work is a separately registered discipline, and anyone who tells you otherwise is a reason to end the conversation.
What the check actually covers
An engineer is looking at the appliances and flues in your demise, and at whether they are safe and working as intended. Broadly that means checking that appliances burn correctly, that the flue removes the products of combustion properly, that ventilation is adequate for the appliance, and that safety devices operate.
What it is not: it is not a service. A check tells you whether the boiler is safe now. A service cleans and maintains it so it stays that way and lasts longer. They are different jobs, they take different amounts of time, and a price that looks cheap is often a check only. Ask which you are buying. In a flat with an old boiler that runs all winter, the service is arguably the better investment; the check is the one the law requires.
It is also not a survey of the whole building's gas installation. In a block, the incoming supply, the riser and the meter arrangements typically sit outside your demise and belong to the freeholder. Where the boundary lies is a matter for your lease, and leases differ — check yours, or ask the managing agent to confirm it in writing.
What we charge
A gas safety certificate is £85, excluding VAT. That is a published, fixed price rather than a starting point, and it covers the annual check and the record.
It is worth being precise about what sits outside it, because this is exactly where a cheap-looking gas price usually hides its costs. A boiler service is a separate job, not a cheaper version of the same one. Any remedial work the engineer finds is quoted before it is done, not added afterwards. And if the check cannot be completed — because the flue is buried in a ceiling with no hatches, or because nobody can get to the meter — you have a building problem to solve rather than a gas problem, and we will tell you that plainly rather than book a second wasted visit.
The reason we publish the number at all is that compliance work should not need a negotiation. You have a date, you have a duty, and you should be able to put a figure in the calendar next to both without three phone calls. Where a certificate is being done alongside other work — the five-yearly EICR, say, or maintenance snags in a void — it is the same visit, the same access arrangement and the same porter booking, which is the real saving and it is a saving in your time rather than ours.
The Central London complications
Flues in voids
This is the big one in purpose-built and converted flats. Where a boiler's flue runs horizontally through a ceiling void or a duct to reach an outside wall — common when the boiler sits in an internal kitchen or cupboard, which is very common indeed in flats — the engineer has to be able to inspect it. That normally requires inspection hatches in the ceiling along the flue run. Where those hatches do not exist, the engineer cannot see the flue, cannot verify it, and is entitled to record the installation accordingly.
Landlords are frequently blindsided by this. The boiler works, nothing smells, nothing is obviously wrong, and the engineer still cannot sign the flue off. The fix is to have hatches installed, which is a small piece of building work — and in a leasehold flat, cutting hatches into a ceiling may itself need the freeholder's or managing agent's agreement, especially if the ceiling is a party structure or the flat is listed. It is worth resolving this once, properly, rather than rediscovering it every single year.
Porters, service lifts and hours
Mansion blocks in St John's Wood, Maida Vale and Little Venice generally run on rules: contractors sign in, use the service entrance, book the lift, and work within set hours. Blocks around Mayfair and Marylebone are often stricter still. An engineer who arrives without being booked in may simply not be let past the front desk, and the visit is lost. If a managing agent controls access, arrange it in the same message that you arrange tenant access.
Meters you cannot get to
Where the meter and the emergency control valve sit in a communal cupboard, someone with a key needs to be present. In converted terraces around Bayswater and Paddington the meter is very often in a hallway cupboard, under a stair, or in a basement area that nobody has opened for months. Establish where the isolation point is before the engineer's visit rather than during it.
Old pipework and long runs
A great deal of this stock has had gas run through it repeatedly over a century. Pipework threaded through voids, buried in walls, or running through a neighbouring demise is not unusual. Anything found in that category is likely to involve the freeholder as well as you, and it is a conversation worth starting immediately rather than at renewal.
When the engineer condemns something
If an appliance is found to be immediately dangerous, it will be disconnected or capped with your permission, and if permission is refused the engineer has reporting obligations of their own. If it is at risk, it will typically be turned off and labelled. Either way you now have a tenant with no heating or hot water, and that is a repairing obligation with its own urgency separate from gas safety.
This is the practical argument for doing gas checks in the autumn rather than in January. If a boiler fails a check in September you have time. If it fails in the first cold week of the year, so has every other boiler in the postcode, and you are joining a queue.
Records and portfolios
Keep the record. Keep proof you gave it to the tenant, with a date. Keep the previous years' records — a run of records tells you whether an appliance is heading towards replacement, which is far more useful for budgeting than a single sheet.
If you hold several flats, put gas on the same annual rhythm as the rest of your compliance. The five-yearly EICR will not line up with the gas anniversary every year, but in the years where they do, one attendance covering both saves a tenant access negotiation, a porter booking, and a day of your life. Agents running blocks find this obvious; private landlords often do not. Our page for estate agents and managing agents sets out how we handle scheduled compliance across a portfolio, and routine maintenance attendance can usually be bolted onto the same visit.
Gas, bathrooms and refurbishment
If you are altering a flat, gas has an awkward habit of dictating the programme. Moving a boiler is not a small job: it changes the flue route, which changes what has to be inspectable, which can change what consent you need from the freeholder. Any bathroom refurbishment that touches the boiler, the hot water arrangement or the ventilation route needs the gas work sequenced early, not squeezed in at the end. The same applies to a broader refurbishment where a kitchen moves — the gas run, the flue and the consent for both should be settled before anyone orders cabinets.
Bathrooms also engage Building Regulations in their own right, including ventilation and hot water provisions, which we cover in our guide to building regulations for bathrooms.
What to ask before booking
- Is this a safety check only, or a check and a service?
- Is the engineer Gas Safe registered, and can you see the registration?
- How many appliances is the price based on?
- What happens if the flue cannot be inspected because there are no hatches?
- Who is arranging access with the tenant, and with the porter or managing agent?
- Will the record be emailed to you and to the tenant, or only left in the flat?
How we handle it
The check is £85 excluding VAT, a fixed quote covers any defined work that follows, there is one point of contact, and the record is sent to you the same day rather than a week later. If something needs attention we tell you what is required and what is advisable, separately, so you can decide. If a flue cannot be inspected we will tell you what would need to happen to make it inspectable — including who you may need to ask — rather than leaving a note and driving off.
Start with the quote form or a message on WhatsApp. If you want gas, electrical and maintenance on one calendar across several flats, say so at the start and we will build it that way.
This is practical guidance rather than legal advice. Gas regulations and the guidance around them are updated from time to time, and you should confirm your specific obligations for your specific property before relying on them.