Ms Sheenagh Rooney:

The CER does dispute the figures.

I would like to think there are verifiable statistics for the numbers of boilers sold, but the truth is there are not. We have tried to replicate the survey conducted in 2011, but have been unable to do so. On a more positive note, we have been engaging with the CSO to find a way to gather these numbers. It is not straightforward, but we are determined to keep going to try to come up with a verifiable number of boilers sold.

It is important to remember that gas is a safe fuel and that boilers are constructed in accordance with international standards. We are also tackling the issue that the number of boilers installed does not necessarily match the number of certificates returned. It could be the case that a boiler has been serviced by a registered gas installer and that he or she has not returned the certificate. This is an issue we have identified with the scheme and we have put much effort into addressing it. Processes are now followed, whereby if a registered gas installer continues not to return certificates, he or she will be suspended from the scheme. This initiative has led to the return of an increased number of certificates. For us, it is about concentrating our efforts on the elements of the scheme which are completely workable but require constant effort such as the work undertaken to improve elements of the scheme and enforcement.

A point was raised about best practice elsewhere. We are confident the key pillars of our system - requiring people to be legally registered, publicising the requirements to be met among the public, and enforcing, where necessary - stack up against any scheme we have come across elsewhere, including Britain and Northern Ireland. We do not tolerate illegal activity and, as we have stated, if anybody contacts us about illegal activity, we will follow up on it and have done so.