Unvented Hot Water Storage Systems to BS6700

Installation, commissioning and servicing of unvented hot water storage systems are classified as a controlled service. Building regulation G3 applies. All work on these systems must be carried out by competent persons who hold a current registered operative ID card issued by an approved and accredited body.

It is important to note that it is an offence to install an unvented system without notifying the local authority. In addition the water undertaker under the Water Regulations 1999 must be notified.

Most unvented hot water systems are required to be tested/serviced at intervals between 12 and 24 months by a competent person.

In the event of an incident involving pressured hot water storage facilities the landlord/owner must be able to prove all reasonable steps had been taken to ensure the equipment is safe.