A Look at Regulations for Unvented Hot Water Cylinders
Unvented hot water cylinders are storage containers for warm water that get their water supply directly from the main water supply pipes that are entering the residence. These items do not have a vent pipe that could relieve an excessive amount of pressure build-up into the atmosphere. The pressure these devices have is gotten from the mains water supply rather than from a holding tank in the attic of the dwelling.
According to the regulations after the amendments were made in 2000 any person that submits a building notice or a set of full plans must provide a statement that includes the name, the make, the model, and the type of hot water storage system they are installing. The statement also needs to include the name of the person that is installing the appliance. If the system has been inspected and approved by a person with the authority to do so their name must be included in the statement.
A competent person must be hired to install these appliances. A competent person is defined as being a registered operative identity card holder. These identity cards are issued by the institute of plumbing or the construction industry training board. The only way to get one of these cards is to have an assessment done by a recognized training body from one of these two places.
The installation must allow for the hot water discharge from all safety devices on the storage tank to be conveyed visibly and safely away from the unit without causing any danger to persons who may be in or above the building. Normally the package will be supplied with a tundish that provides a visible indication of water being spewed from the safety valves located on the unit. This tundish has to be within 500mm of the safety valves that will spew the hot water. The discharge pipe from the tundish on the unit is required to be a size larger than the pipe that enters into the tundish. This larger pipe coming from the tundish will have to terminate in an area that will not let the warm water pose a burn threat to the any person. If a system does not have an internal air gap the regulations require that there be an external expansion valve on the cold water feed.
It seems at times that regulations on items like these are designed to inconvenience people. The truth of the matter is, the regulations are designed to keep people safe from possible hazards that a device might have.
Unvented hot water cylinders have regulations about who can install them and the type that can be installed. The regulations concerning unvented hot water cylinders are in place to protect the public from harm in the event of a malfunction. You can find out more by clicking this link.