Landlord’s Legal Duty: Why a CP12 & Boiler Service Matters
Key Takeaways

Skip to:
The last call a landlord wants to receive is the news that their property’s boiler has malfunctioned. It’s not just an inconvenience; it’s a legal duty for landlords to ensure their property has a valid CP12 (or a Gas Safety Certificate).
In the UK regular boiler services are not a legal requirement, but are crucial in preventing breakdowns. UK landlords must have a CP12 for every gas appliance in their rental property. Failure to comply with this requirement can result in hefty fines and, more importantly, unsafe appliances.
To receive a CP12, you need a gas safe registered engineer to conduct an inspection. However, do only UK landlords require an annual CP12?
Key Takeaways:
- Every UK landlord must provide proof of an up-to-date gas safety certificate.
- Gas safety certificates only last 12 months and are the same as a CP12.
- In the UK, it is illegal to use a gas appliance if there is a suspicion that it might be faulty.
- UK Landlords must deal with gas appliances that fail inspection.
Who Requires a CP12?
Anyone using a property to accommodate a tenant is legally required to complete a CP12 check. These safety checks are required by:
- UK landlords
- Housing associations
- Hotels
- Bed and breakfasts
- Colleges
- Boarding schools
- Hostels
- And more
For properties like a hotel or B&B, an annual check is required for gas appliances serving the guests’ accommodation, even if the item is away from their rooms.

If you’re unsure whether your property requires a CP12, here are some quick tips to clarify the situation:
- Those with a family member living rent-free in their home will not require a CP12;
- If you have staff living on your property, you must arrange an annual gas safety check;
- An empty property, due to a changeover in tenants, will still require a CP12 to cover this period;
- You must organise a gas safety check when renting a flat above your commercial property (like a corner shop).
Now that we know who needs to apply for a CP12, what is it?
What’s a CP12?
For those interested, CP12 is the abbreviation of CORGI Proforma 12. From 1991 to 2009, CORGI (the Council for Registered Gas Installers) was the legally authorised regulatory body for UK gas installers.
Technically, you’re looking for a Gas Safety Certificate to file away in your mandatory gas safety records. However, those in the industry still call it a CP12 certificate.
This certificate is a report outlining the gas appliances with gas pipe work, which are tested during an annual gas safety check.
A Gas Safety Certificate, or a CP12, is a legal requirement (As per The Gas Safety (Installation and Use) Regulations 1998, Section 36 (3)(c)) for landlords and owners of domestic premises that use gas appliances in the UK. All gas appliances must be tested regularly to ensure they work efficiently and safely.
Once you have received your Gas Safety Certificate, it is valid for twelve months (a year) and must be renewed annually. As a landlord, you must provide your tenants with a copy of the gas safety certificate within 28 days of receiving the certification.
Landlords are legally required to keep a copy of the form on file for at least two years to allow any auditing to be carried out should it be deemed necessary in a Landlord Gas Safety Record (LGSR).
The engineer must be listed on the Gas Safe Register to issue this certificate. The website allows everyone to review the records to ensure their engineer is certified and registered.
But what exactly is checked during this inspection?
What Is Checked For A CP12 Certificate?
Once they have permission, your gas-safe engineer has a lot on their plate when performing their annual check. But firstly, they will need access to manufacturer documents when checking all the gas appliances in your home, so it’s pretty important to keep these after purchasing a new appliance.
Manufacturers will outline if there is any task that is vital to perform or replace. However, if you have lost the manuals or bought a second-hand appliance without one, you can access this information online in the modern world.
When they’re ready, the engineer will test how well your boiler or the gas appliances work. General checks will include testing equipment to gauge whether the appliances are appropriately operational. They will also evaluate the fuse rating for the boiler or particular appliance.
After completing this testing stage, the engineer will remove the boiler’s case and perform a visual inspection to determine any internal or external signs of distress, such as corrosion or water leaks.
Now that the heating engineer has completed the inspection of the unit, they will perform a visual test of the boiler’s flame, its safety device, and conduct a flue-gas analysis using a gas analyser, plus a visual inspection of the flu itself.
After completing this step, the engineer will check that all the safety devices are working correctly.
If there are any issues, the engineer will either assist in fixing them or advise you on how to comply with the information supplied regarding the Gas Industry Unsafe Situations Procedure.




But what happens if there is an issue with the Gas Safe Certificate?
What Happens If Your Gas Appliances Fail?
If the Gas Safe registered engineer finds that any of your appliances are unsafe and cannot immediately fix them, they will ask your permission to switch off the gas supply.
If they deem the issue dangerous, they will report it under RIDDOR (Reporting of Injuries, Diseases, and Dangerous Occurrences Regulation). The law requires that the engineer provide details of hazardous gas appliances or fittings.
Under RIDDOR, employers or individuals responsible for a workspace must report and keep records of:
- Work-related accidents which cause death
- Work-related accidents which cause specific serious injuries (reportable injuries)
- Dangerous occurrences with the potential to cause harm. There are special requirements for gas incidents.
A registered gas engineer must provide a detailed report of the appliances or fittings they consider dangerous.
The engineer is making sure the gas appliance doesn’t pose a danger and meets the required safety standards by looking at the following:
- Design of the appliance
- Construction
- Installation
- That any modifications are done correctly
- Fitting of the appliance
- And whether it has been serviced at regular intervals
Because many elements can cause a failure during a CP12 inspection, you should book it with time to spare on the last valid Gas Safe Certificate issued.
If your Gas Safe engineer can’t fix your appliance, they will attach a label to indicate how dangerous the device is for the next gas safe engineer. These labels are:
- Not to Current Standards (NCS): if the appliances technically work safely but don’t meet current safety standards.
- At Risk (AR) indicates that the appliance cannot be used and is considered dangerous to life and property. There are issues that, without repair, would endanger lives.
- Immediately Dangerous (ID): This indicates that the appliance cannot be used and is considered a danger to life and property. It should be disconnected from the gas supply immediately.
Landlords who refuse to allow an engineer to make their appliances safe will be reported to the Gas Emergency Service Provider, who has the legal right to enter a property to make a dangerous situation, safe.
Also, if you have experienced a dangerous gas-related event, you have 14 days to report it to a Health and Safety Executive.
How Much Does a CP12 Inspection Cost?
Pricing for a CP12 inspection can vary between £60 and as much as £150 plus vat. Several factors can affect the price, including the size of the property, whether the gas appliances are simple or complex, and whether little to no maintenance has been performed in the past.
Another factor to remember is the location of your property. Gas Safety Certificate costs can be 10% to 25% higher if it is located in an urban, high populated areas.
The cost of the CP12 does not include any repairs you may need to complete the Gas Safety check.
So, is it worth it to get a CP12 completed annually? After all, it seems more trouble to complete than simply ignoring it.
Do I Have To Book a CP12 Annual Inspection?
The short and only answer to the question is – yes! It is always imperative that you book a CP12 annually.
Gas appliances are a resource we use daily, but gas can be dangerous.
There are two main gas accidents that can take place, which include:
- Active explosions
- Carbon monoxide poisoning
While explosions are generally rare, according to the HSE (Health and Safety Executive), they have doubled over the last five years. (Important Note: The HSE itself does not explicitly state that explosions have doubled in their official reports. However, the analysis by CE Safety of HSE data provides evidence supporting this claim, specifically regarding gas explosions in the workplace.)
Another fact to consider is that 34% of unintentional carbon monoxide poisoning between 1995 and 2021 was caused by gas leaks.
According to the NHS, 60 people in England and Wales die annually due to accidental carbon monoxide poisoning.
Another important fact we’ve mentioned before is that most UK insurance companies will need an up-to-date CP12 certificate before providing insurance to landlords.
Suppose you’re not convinced yet of the value of keeping your CP12 certificate up to date. In that case, landlords who fail to provide one can face multiple penalties, especially if someone is injured or dies from a gas-related incident.
These penalties include:
- Being sent to prison
- Receiving a fine up to £20,000 and possibly more
- And even facing charges of manslaughter
When looking for a company to issue you with a CP12 certificate, there are several factors to consider. Firstly, make sure to conduct research about the local gas-registered engineers. While most will assume that a more minor local player will be cheaper, this is often not the case.
Also, make sure to check what services are included in the quote, some of which are:
- Same-day gas safety check
- Gas safety certificate delivered within 24 hours
- Or if you can download the certificate online
Now that you’re motivated to get your CP12 certificate issued, what does it say?
What Does a Gas Safe Certificate Say?
When issued with a Gas Safe Certificate, it will include the following information:
- Name, ID number and signature of the Gas Safe registered engineer
- The date of the inspection
- Name and address of the landlord or letting agent
- Address of the property
- Location and details about every piece of equipment tested
- All issues and any action needed to remedy them
- Confirmation from the engineer that they checked appliances correctly and that the home is in compliance with legislation.
At the bottom of the certificate will be when you must schedule your next gas safety check.
Your Gas Safe Certificate is usually distributed at a later stage, but on the day the engineer issues proof via a bulky pad with ink-blot paper, you’ll get some sort of proof that a successful inspection was done, but this isn’t the certificate.




Before the engineer starts the inspection, you should ask to see their Gas Safe card.
This card will include the following:
- Photo confirming the engineer’s identity
- Name of the company
- Validity dates of the engineer
- Their licence number
- And the Gas-Safe security hologram
As the landlord, you will receive the certificate or a digital copy within 24 to 48 hours of the inspection.
Also, by digitising the certificate, you can instantly share it with anyone. When new tenants are moving into your property, you should get a CP12 inspection completed before they move in. New tenants are legally required to have a copy of the CP12 within 28 days of occupying the rental.
The Gas Safe Certificate should be included in the letting pack of documents (documents recording the property’s condition).
Now that we’ve covered all the legal requirements, can a landlord instruct their tenants to complete this work?
Responsibilities of Landlords
Legally, landlords cannot delegate any gas safety responsibility to their tenants. If it is written in the rental agreement, this is not legally binding.
According to the Smoke and Carbon Monoxide Alarm Regulations 2015, landlords must install at least one working Carbon Monoxide alarm in a room where gas appliances are being used.
However, if the tenant has brought in and installed their own appliances, they must inform the landlord and ask for permission, and keep records of their correct installation and safety.
If they have multiple properties, landlords can potentially receive a discount on the total cost of the certification.
The simple truth is that having a Gas Safety certification means having peace of mind and ultimate safety.
Boiler Servicing to Protect Your Investment
As landlords, ensuring the ongoing functionality and safety of our boiler systems is a crucial aspect of property maintenance. Annual boiler servicing plays a vital role in achieving these objectives.
What Happens in a Boiler Service
A Gas Safe registered engineer will come out to your property and give your boiler a thorough once-over. They’ll check for:
- Combustion tests including the flue using a gas analyser.
- Ensure the correct gas and flow temperatures are present.
- Check all seals.
- Ensure all safety devices are operational.
- Clean and check all electrical connections.
- Clear the condensate trap, if required.
- Check all gas and water connections to the boiler for leaks.
- Check your system filter.
- Provide advice on correct operational use.
A service certificate is then issued detailing what has been done and any follow on works (if applicable).
What Doesn’t Happens in a Boiler Service
Although a Boiler Service covers a lot to ensure the boiler is running correctly and efficiently, they will not:
- No boiler repairs are made during the service.
Why Should I Swallow the Yearly Cost of a Boiler Service?
Regular boiler servicing isn’t just about safety and legal compliance; it’s a smart financial move too. A well-maintained boiler runs more efficiently, which means it uses less fuel to heat your property, leading to lower energy bills. This can be particularly useful when the tenancy agreement includes a clause where the Landlord covers the bill, including gas.
Plus, catching minor issues early can prevent them from developing into costly breakdowns, saving you from hefty repair or replacement bills down the line. Think of it as an investment in the long-term health of your boiler, your tenant’s comfort, and your own financial peace of mind.
Remember, a boiler service isn’t just a box to tick – it’s about protecting your investment and your tenants. So, make sure you book yours annually with a Gas Safe registered engineer. Your boiler (and your wallet) will thank you.
Still, Have More Questions?








About the Author