If you rent out a property in Hertfordshire, a gas safety certificate isn't optional — it's a legal requirement. Yet we get calls every week from landlords who aren't sure what they need, how often they need it, or who should carry out the inspection. This guide covers everything clearly.
What Is a Landlord Gas Safety Certificate?
A landlord gas safety certificate — officially called a CP12 — is a document issued by a Gas Safe registered engineer after they've inspected all gas appliances, flues and fittings in your rental property. It confirms everything is safe and working correctly.
The certificate must be issued every 12 months. Miss that window, even by a few days, and you're in breach of the Gas Safety (Installation and Use) Regulations 1998.
What Does the Inspection Cover?
During a CP12 inspection, a Gas Safe registered engineer will check:
- Boiler — condition, combustion, flue integrity, safety devices
- Gas hob or cooker — burner condition, ignition, stability
- Gas fires or decorative flame effects — ventilation, heat output, CO emissions
- Pipework — visible pipework for leaks, corrosion or poor installation
- Flues and ventilation — that combustion gases are safely expelled
If an appliance fails, it will be marked 'at risk' or 'immediately dangerous' on the certificate. Immediately dangerous appliances must be disconnected — tenants cannot be allowed to use them.
What Are Your Legal Obligations as a Landlord?
Under UK law, as a landlord you must:
- Have all gas appliances and flues inspected annually by a Gas Safe registered engineer
- Provide a copy of the certificate to existing tenants within 28 days of the inspection
- Provide a copy to new tenants before they move in
- Keep records of certificates for at least two years
There is no grace period. If your tenants move in on 1 March and your CP12 expired on 28 February, you are non-compliant.
What Happens If You Don't Have a Valid Certificate?
The consequences of non-compliance are serious:
- Fines up to £6,000 per offence from the Health and Safety Executive (HSE)
- Criminal prosecution in serious cases
- Insurance claims may be void — many landlord insurance policies exclude gas incidents if there's no valid CP12
- Section 21 notices may be invalid — courts have ruled that landlords cannot evict tenants using a Section 21 notice if they failed to provide a gas safety record
Beyond the legal risk, an uninspected gas appliance is a genuine safety hazard. Carbon monoxide poisoning kills around 40 people in the UK every year — most of them in properties with faulty or poorly maintained gas appliances.
Do HMOs (Houses in Multiple Occupation) Need a CP12?
Yes. In fact, HMO landlords are often subject to additional requirements under their licence conditions. If you own an HMO in Hertfordshire — whether in Watford, St Albans, Hemel Hempstead or elsewhere — check with your local council whether any additional gas safety conditions apply to your licence.
How Long Does a CP12 Inspection Take?
A standard CP12 inspection for a property with a boiler and gas hob typically takes 45 minutes to 90 minutes. Larger properties with multiple gas appliances will take longer. We'll always tell you the likely duration when you book.
How Much Does a Landlord Gas Safety Certificate Cost in Hertfordshire?
CP12 inspection costs in Hertfordshire typically range from £60 to £110 depending on the number of appliances and the property location. Some companies offer discounts for landlords with multiple properties. We're happy to discuss rates if you have a portfolio.
Can I Be Present During the Inspection?
You don't need to be present, but you must ensure the engineer has access to the property and all gas appliances. Coordinate access with your tenants in advance — if the engineer can't get in, you'll still be charged a call-out fee.
What If the Boiler Fails the Inspection?
If the boiler or another appliance fails, the engineer will explain the fault and your options. Minor issues may be repairable on the day. More serious faults may require a return visit or a new appliance. If an appliance is classified as 'immediately dangerous', the engineer is required to disconnect it — with your permission, or if they cannot reach you in an emergency.
Book Your CP12 in Hertfordshire
We issue same-day CP12 certificates for landlords across Hertfordshire — covering Watford, St Albans, Hemel Hempstead, Stevenage, Rickmansworth, Hertford, Barnet, Edgware and all surrounding areas. All inspections are carried out by Gas Safe registered engineers (No. 936121).
Call us on 0208 092 1359 or get in touch to book. We'll confirm the appointment within the hour.