Certification - Unvented Heating Systems

Introduction

Prior to 1985 it was illegal to install an unvented hot water storage system with a capacity greater than 15 litres directly connected to the cold water mains supply.

With the introduction of the Building Regulations 1985, a relaxation of the Water Byelaws current at the time and the Water Byelaws which came into force on the 1 January 1989, such systems may now be installed in the UK.

Testing Requirements

Because of the differences between unvented hot water storage systems and traditional vented hot water storage systems within the UK regarding the requirements for safety devices, it is essential that unvented systems comply with the Building Regulations and that installers are competent i.e. one holding a current Registered Operative card for the installation of unvented domestic hot water storage systems.

The requirements of the Building Regulations G3, state that all systems must be either:

1. approved by a member body or the European Organisation for Technical Approvals (EOTA) - operating a technical approvals scheme e.g. meeting the relevant requirements of G3;or
2. approved by a certification body having National Accreditation of Certification Bodies (NACB) accreditation and testing to the requirements of an appropriate standard that will ensure that the requirements of Regulation G3 will be met e.g. BS 7206:1990, or
3. the subject of a proven independent assessment that will clearly demonstrate an equivalent level of verification and performance to a. or b. above.

Accredited Testing

The WRc-NSF Evaluation and Testing Centre is the only UKAS accredited laboratory in the United Kingdom able to carry out the tests to establish that units comply with Part C. of G3 of the building regulations 1992.

WRc-NSF is also the only UKAS accredited laboratory in the UK able to test to all the requirements of BS 6283 Parts 1 to L', (safety devices used on unvented hot water storage systems).

WRc-NSF is one of the few laboratories in Europe which is equipped to test to the requirements of the forthcoming European Standards.

With the introduction of European Directives and with the Water Regulations now being enforced by the water suppliers, investment in technology by WRc-NSF in recent years, has established the centre as the leader in the field for testing products for drinking water supply.

For further information contact Mr Ian Broad.