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Issuing Gas Safety Certificates for Landlords in Marlow, Buckinghamshire

As a landlord, you are legally responsible for the safety of your tenants in relation to gas safety. By law, you are required to:

  • Repair and Maintain Gas Pipework and Appliances to a Safe Standard
  • Ensure an Annual Gas Safety Check Is Carried out on Each Appliance in the Property, Including Flues and Ventilation
  • Keep a Record of Each Annual Safety Check and Make It Available at the Tenant's Request

At RS Boiler Services, in Marlow, Buckinghamshire, our engineers are qualified to complete gas safety inspections and issue landlord gas safety certificates (CP12s). For landlords with multiple properties, we offer discounts on our already-low prices. To book an appointment or receive more information, give our helpful team a call.

Gas Boilers - Flues in Voids (Updated 20th May, 2013)

The purpose of the original alert was to raise awareness of the potential dangers from certain types of flues connected to gas-fired central heating installations in some properties (particularly, but not exclusively, a large number of flats and apartments completed since around 2000) that may not have been installed properly, or may have fallen into disrepair.

Where boilers are located away from external walls, flues are more likely to run through ceiling (or wall) voids. In such cases, when the gas appliance is serviced or maintained it can be difficult, or impossible, to determine whether the flue has been installed correctly or whether it is still in good condition. Where a flue fault exists in combination with a boiler which is not operating correctly, dangerous levels of carbon monoxide (CO) could be released into the living accommodation.


The introduction of fan-flued gas appliances in the mid-1990s allowed gas central heating boilers to be installed away from external walls. This meant that builders could design new-build and refurbishment properties with boilers being installed on internal walls to make better use of the available space. The flues to these boilers were, in some cases, routed through voids in the ceiling space (and through stud walls) between properties above.

This practice became progressively more popular from 2000 onwards, and the vast majority of affected systems are thought to be located in new build flats and apartments completed since 2000. It is, however, possible that other types of homes may have similar central heating systems installed.

Gas engineers are legally required to check the flue after carrying out any work on the boiler. This will include a visual inspection. Similarly, when an engineer installs a boiler they need to ensure that it can be used without constituting a danger to anyone. This would include checking whether the flue is safe or not. The original installer, and every subsequent servicing or maintenance engineer, need to be able to check that:

  • The Flue Is Continuous throughout Its Length
  • All Joints Are Correctly Assembled and Are Appropriately Sealed
  • The Flue Is Adequately Supported throughout Its Length

Unless the gas engineer can make these checks, they cannot ensure that the flue from the boiler is safe in order to comply with their legal duties. This necessitates the provision of appropriate inspection hatches in the ceiling and, where relevant, stud wall.

Action Required

The revised technical guidance requires inspection hatches to be fitted in properties where the flue is concealed within voids and cannot be inspected. The homeowner (or landlord etc.) has until 31st December, 2012 to arrange for inspection hatches to be installed. Any gas engineer working on affected systems after 1st January, 2013 will advise the homeowner that the system is "at risk" (AR) in accordance with the GIUSP and, with the owner's permission, will turn off the gas supply to the boiler so it cannot be used.

In the interim period, where no inspection hatches are fitted, the registered gas engineers will carry out a simple risk assessment which should ensure that the risk from exposure to CO is managed in the short-term. This risk assessment includes:

  • Looking for Signs of Leakage along the Flue Route
  • Carrying out a Flue Combustion Analysis Check (and Obtaining a Satisfactory Result)
  • Checking for the Presence of Suitable Audible Carbon Monoxide (CO) Alarms (and Installing Such Alarms Where They Are Not Already Fitted)

As long as this boiler passes the series of safety checks, and the risk assessment does not identify any concerns about its safety, it can be left on. Suitable inspection hatches will, however, need to be fitted to the ceiling (or wall, as appropriate) by 31st December, 2012. Wherever possible, it is recommended that inspection hatches are fitted before this date. Once inspection hatches have been fitted, the gas engineer will be able to make sure that the flue is safe and was installed in line with the relevant standards and manufacturer's instructions.

If a property has concealed flues in voids and no inspection hatches:

  • If the Property Is Less Than Two Years Old, Contact the Original Builder for Assistance with the Retrofitting of Inspection Hatches and Repair of Any Flue Defects.
  • If the Property Is between Two and 10 Years Old, Contact the Home Warranty Provider as You May Be Covered by Them If There Are Defects in the Flue. The Main Warranty Providers (NHBC, Premier Guarantee, and Zurich Building Guarantee) Have, However, Advised That Cover Is Not Provided for Installing Inspection Hatches in Homes More Than Two Years Old.
  • If the Property Is 10 or More Years Old, You Should Contact a Gas Safe-Registered Engineer. You or Your Landlord Will Have to Meet the Cost of the Inspection Hatches and Any Defects to the Boiler or Its Flue. It May Still Be Worth Contacting the Home Builder Who May Be Able to Assist in Some Way, or Be Able to Recommend Reputable Building Services Companies to Carry out the Work.

An Alternative to the Above

Gas and oil-fired boilers require flues to extract dangerous gases produced during combustion from the property they are contained within. Electric boilers, however, do not use combustion to produce the heat we need to circulate through your central heating system, and as such do not require any flue at all. We have seen a huge increase in demand for electric boilers since this new guideline came into force in 2012. It is our belief, however, that many properties still run the risk of falling foul of this new legislation and a potential hazard still remains.

An electric boiler can be installed in much the same way as a conventional gas or oil-fired boiler, can be just as efficient, and can be linked together to allow multiple units in series to create enough energy to heat larger homes. They are also often a lot smaller than conventional gas or oil boilers, so small homes where space is of a premium will benefit most.

Contact us now, in Marlow, Buckinghamshire, for more details about landlord gas safety certificates.