Since 1st January 2013, the Gas Safe Register (formerly CORGI) regulations have required any registered engineer servicing your boiler to visually inspect the flue which runs through the ceiling void of your apartment.  

If the service engineer cannot visually inspect the flue, then they must advise you that the appliance is "At Risk", and will ask you to turn it off (which you can politely decline).  Note that they are still permitted to service the boiler as usual.

Why is this important?

A corroded or damaged flue pipe could leak poisonous Carbon Monoxide (CO) gas into your apartment.  Carbon Monoxide is odourless, tasteless and colourless, and can be deadly - around 40 people a year die in the UK from CO poisoning.

When Providence Square was built, the flues were concealed in the ceiling voids, and in most central apartments run within the ceiling of the shower room and bedrooms, exiting through the back wall.  

What do I have to do about it?

Firstly, we would always recommend fitting a Carbon Monoxide detector / alarm in your flat - these are relatively cheap (similar to smoke alarms) and may well save your life.

We believe there are currently five main options - please let us know if you have any others:

  • Do nothing (only if you are a resident owner, not if you rent the flat out)
  • Get inspection hatches fitted in the ceiling of your shower room and bedroom, to allow the flue to be visually inspected along its entire length
  • Replace the gas boiler with an electric boiler
  • Have a Ceiling Void Carbon Monoxide detector fitted - this is a recent development
  • Replace the gas boiler with another gas boiler - note that this doesn't solve the problem

Option 1 - Do nothing (but continue to get your boiler serviced)

Clearly not recommended, but if you are a resident owner, you are perfectly at liberty to continue to get your boiler serviced, and each time decline the engineer's request to turn it off  In this case, the engineer will ask you to sign a disclaimer/waiver so that he is not liable, and he will stick a warning notice on the boiler.

You can repeat this process every year when the boiler is serviced.  

Although this isn't ideal, it's a far better option (and much safer) than not having your boiler serviced at all!

If you rent your flat out, please this is not an option - as the landlord, you are legally obliged to make the appliance safe.

Option 2 – Keep the existing boiler and install flue inspection ports

flue floorplanThe new regulations require that each joint in the boiler flue can be inspected.  This will require cutting into the ceiling along the flue route to provide access.

In an end flat where the flue run is relatively short (2 m) the number of ports would probably be 1-2 in the kitchen.

In the typical 2 or 3 bedroom “internal” flat (flue runs of 7-8 m) this would mean 3-4 ports. Probably one in the shower room, one in the master bedroom entranceway and one or more in the smaller bedroom, depending on where the joints are in the flue. See attached floor plan.

Note: The flues are probably covered with insulation that may need to be removed to locate the joints. The situation in the top floor flats could be different.

Quotes for installing ports have been £75 per port for just cutting out a section of ceiling and replacing the cut out section into the hole with screws, and £150 per port (for 3 ports) for installing white coated steel hatches. The actual cost could vary depending on what the installer runs into.

Asbesco Ltd. has installed hatches in Providence Square.

Option 3 - Replace the existing boiler with an electric boiler

There are basically two types of electric boiler systems: Direct and Indirect.

In the direct system there is a separate flow boiler for the central heating, and a separately heated tank for the domestic hot water. This system is the simpler of the two, and would usually be a little less expensive but the tank recovery time is longer. The running costs can be reduced by installing an economy 7 timer to use cheaper electricity overnight; this would also require a new electricity meter to be fitted.

In the indirect system, the flow boiler heats both radiators and the domestic hot water through an internal coil and the tank has a faster recovery time. The tank will also usually have a separate auxiliary heater which provides some degree of back-up if the flow boiler were to fail.

Given an appropriately sized hot water tank either system should work well, although some residents have reported that their radiators heat up more slowly than with the gas boiler.

The quotes obtained run from about £3,800 to £6,000, depending on the company and the choice of equipment. Some companies may give a discount (5%?) where owners can get together to coordinate installations.

Aspect and Gas-elec have each installed new electric boiler systems in Providence Square. A new higher-capacity electricity cable is required between the boiler and your main fusebox (usually in the hall cupboard), but in most cases this can be done without damaging the hall ceiling.

Some concern has been raised as to the capacity of the electricity supply to Providence Square if everyone were to have an electric boiler fitted. FirstPort have contacted their electrical contractor, who has confirmed that this should not be a problem. Each apartment has a 100A (24 kW) main switch/fuse, and the building would have been designed for worst-case scenarios where each apartment was taking the full 100A.

Electric boiler capacities vary from 3kW (13A) to 12kW (50A), which should still leave plenty of spare capacity.

Option 4 – Have a ceiling void Carbon Monoxide monitor fitted

As an alternative to inspection hatches, it is acceptable to fit a special Ceiling Void monitoring safety shut off system.  This must be professionally installed, and will shut off the boiler automatically if any CO gas is detected in the ceiling void; these cannot be reset until a registered engineer has investigated the cause (special keycodes are required).

We're not aware of anyone in Providence Square yet having a CO void monitor fitted as an alternative to inspection hatches - please let us know if you have.

There are relatively few systems available; the cost of the equipment appears to be around £250 - more information can be found by following this link:

Option 5 – Replace the existing boiler with a new condensing gas boiler.

New gas boilers are condensing boilers that require the flue to slope upwards at a 2-3 degree angle from the boiler to the exhaust outlet. Gas boilers are therefore best mounted on an outside wall.

In an end flat where only the kitchen is between the boiler and the outside wall, a new gas boiler can be installed in the boiler cupboard with the flue running visibly over the kitchen cabinets inside the kitchen if there is sufficient clearance above the cabinets.

In the inside flats where there are several rooms between the boiler and the outside wall, installing a new flue into the ceiling void would involve considerable disruption (cutting into the ceiling in hallway and bedrooms) and is probably not a practical solution.  It is not possible to re-use the old the flue.

A seperate drain connection must also be fitted for the condensate (the boiler can produce around 4 litres per day).

It's important to note that the same regulations on flue inspection apply to any new gas boiler - inspection hatches must be fitted.  Ceiling Void Carbon Monoxide monitors are NOT permitted for new installations.

Domestic and General Heating have installed a new gas boiler in a Providence Square end flat.

Suggested points of contact

Several flat owners in Providence Square have been in contact with a number of companies who have sent engineers to view their situations and to review the alternative actions that can be taken to bring the boiler systems into compliance with the new regulations. They include:

  • Asbesco Ltd 020 3432 55962.
  • Aspect 0 800 663 22553.
  • Boilers R Us 8859 54974.
  • British Gas 0 800 197 33075.
  • Domestic and General Heating 01902 4050006.
  • Gas-elec 01372 811 5117.
  • Pimlico Plumbers 7928 88888.
  • South and Central Gas Appliances 7277 1702


Please let us know by email (This email address is being protected from spambots. You need JavaScript enabled to view it.) if you have any experience or recommendations you can share with others, particularly around the costs and disruption of any work you've had done, or any other suppliers that were good (or bad).