Grandfathers’ Rights : Ventilation with no interlock
As you will know, under certain conditions – installation dating from before 2001 – it is permissible to operate gas appliances in a kitchen without an interlock.
However, it is not MCFT policy to support this approach – in the 20 years that the new regs have been in, there has been more than enough time to implement the new system, especially as it’s usually, not particularly onerous or expensive.
The particular aspect we need to be wary of is, by our involvement or enabling of such an ongoing situation, and as the customer’s deemed “gas experts”, we might be viewed as complicit in the event of a problem.
To that end, we have reviewed the Gas Manual to add a page on how and when this is allowed and making it very clear that it is the Duty-holder (customer or intermediary managing their assets eg CBRE) who take full responsibility for the decision not to fit an interlock.
To that end, when completing a gas certificate, you must ask to see evidence of their assessment :

To my mind, if they pursue this route, they should also demonstrate a process for verifying that “system of work” is being followed – who checks, when, where is this recorded?
If you do not see this evidence – and to be clear – you must not do any of this work for them or you will be taking personal responsibility for any incidents - then you cannot issue a gas certificate.
As you know, whilst we always try and help customers get around problems, we are clear that none of that will include cutting corners or circumventing the rules – or, as in this case, taking partial responsibility for something which could end badly.
Our procedure will be
- Issue a warning notice AR (take photo) – draw attention of customer to pg 13 in MCFT Gas Manual
- Site to produce and display suitably worded signs (take photos)
- Site to produce written safe system of work and procedures (take photo)
- Evidence of permanent source of supply air (take photo)
- Engineer to produce quotation for interlock system to be fitted.
(for large interlock system MCFT will introduce a specialist sub-contractor.)
Please come back to me or to any on the committee with any concerns or feedback from customers.
Chris Craggs

