This section has no associated Explanatory Memorandum
17.—(1) Every unvented water heater, not being an instantaneous water heater with a capacity not greater than 15 litres, and every secondary coil contained in a primary system shall—
(a)be fitted with a temperature control device and either a temperature relief valve or combined temperature and pressure relief valve; and
(b)be capable of accommodating expansion within the secondary hot water system.
(2) An expansion valve shall be fitted with provision to ensure that water is discharged in a correct manner in the event of a malfunction of the expansion vessel or system.