AIM

As permitted under regulation 4 a method of installation approved by the water undertakers

Approved contractors

As defined in regulation 1, a person who:

(a) has been approved by the water undertaker for the area where a water fitting is installed or used, or

(b) has been certified as an approved contractor by an organization specified in writing by the regulator.

Backflow

Flow upstream, that is in a direction contrary to the intended normal direction of flow, within or from a water fitting.

Interpretation given in schedule 2 paragraph 1

Cistern

A fixed container for holding water at atmospheric pressure.

Interpretation given in schedule 2 paragraph 1

Combined storage

A cistern for supplying cold water to a hot water system without a separate expansion cistern.

Interpretation given in schedule 2 paragraph 1

Contamination

Includes any reduction in chemical or biological quality of water due to a change in temperature or the introduction of polluting substances.

Interpretation given in schedule 2 paragraph 1

Distributing pipe

Any pipe (other than a warning, overflow or flushing pipe) conveying water from a storage cistern, or from hot water apparatus supplied from a cistern and under pressure from that cistern.

Interpretation given in schedule 2 paragraph 1

Expansion valve

A pressure-activated valve designed to release expansion water from an unvented water heating system.

Interpretation given in schedule 2 paragraph 1

Fluid categories

As defined in regulation 1, a category of fluid as described in schedule 1.

Schedule 1:

Fluid Category 1

Wholesome water supplied by the undertaker and complying with the requirements made under section 67 of the Water industry Act 1991/ the Water Supply (Water Quality) (Scotland) Regulations 1990 and any amendment

Fluid Category 2

Water in fluid category 1 whose aesthetic quality is impaired owing to:

• a change in its temperature, or
• the presence of substances or organisms causing a change in its taste, odour or appearance, including water in hot water distribution systems.

Fluid Category 3 

Fluid which represents a slight health hazard because of the concentration of substances of low toxicity, including any fluid which contains:

• ethylene glycol, copper sulphate solution or similar chemical additives, or

• sodium hypochlorite (chloros and common disinfectants)

Fluid category 4 

Fluid which represents a significant health hazard because of the concentration of toxic substances, including any fluid which contains:

• chemical, carcinogenic substances or pesticides (including insecticides an herbicides), or  
• Environmental organisms of potential health significance

Fluid Category 5

Fluid which represents a serious health hazard because of the concentration of pathogenic organisms, radioactive or very toxic substances, including any fluid which contains:

• faecal material or other human waste:
• butchery or other animal waste: or
• pathogens from any other source.  

Flushing cistern

A cistern provided with valve or device for controlling the discharge of the stored water into a water closet pan or urinal.

Interpretation given in schedule 2 paragraph 1

Material change of use

As defined in regulation 1. A change in the purpose for which, or the circumstances in which, premises are used, such that after that change the premises are used (where previously they were not so used)

(i) as a dwelling;
(ii) as an institution;
(iii) as a public building; or
(iv) for the purposes of the storage or use of substances which if mixed with water result in a fluid which is classified as either fluid category 4 or 5;

Notification

As defined in regulation 5, the requirement to provide the water undertaker with advanced notice of a proposal to install a water fitting .

Overflow pipe

A pipe from a cistern in which water flows only when the water level in the cistern exceeds a predetermined level.

Interpretation given in schedule 2 paragraph 1.

Pressure relief valve

A pressure-activated valve which opens automatically at a specified pressure to discharge fluid.

Interpretation given in schedule 2 paragraph 1

Primary circuit

An assembly of water fittings in which water circulates between a boiler or other source of heat and a primary heat exchange inside a hot water storage vessel, and includes any space heating system.

Interpretation given in schedule 2 paragraph 1

Secondary circuit

An assembly of water fittings in which water circulates in supply pipes or distributing pipes of a hot water storage system.

Interpretation given in schedule 2 paragraph 1

Secondary system

An assembly of water fittings comprising the cold feed pipe, any hot water storage vessel, water heater and pipework from which hot water is conveyed to all points of draw-off.

Interpretation given in schedule 2 paragraph 1

Servicing valve

A valve for shutting off for the purpose of maintenance or service the flow of water in a pipe connected to a water fitting.

Interpretation given in schedule 2 paragraph 1

Stop valve

A valve, other than a servicing valve, used for shutting off the flow of water in a pipe.

Interpretation given in schedule 2 paragraph 1

Storage cistern

A cistern for storing water for subsequent use, not being a flushing cistern.

Interpretation given in schedule 2 paragraph 1

Temperature relief valve

A valve which opens automatically at a specified temperature to discharge fluid.

Interpretation given in schedule 2 paragraph 1

Terminal fitting

A water outlet device.

Interpretation given in Schedule 2 paragraph 1

Vent pipe

A pipe open to the atmosphere which exposes the system to atmospheric pressure at its boundary.

Interpretation given in schedule 2 paragraph 1

Workmanlike manner

As defined in regulation 4(6).

The installation, connection, alteration, repair or disconnection of a water fitting must be carried out in a workmanlike manner, which is to say the work must be carried out so as to conform:-

• to an appropriate British Standardor some other national specification which provides an equivalent level of protection and performance;
• to a specification approved by the Regulator; or
• to a method of installation approved by the water undertaker.