A 28
CAP. 102]
Waterworks Regulations
[1989 Ed.
[Subsidiary]
9. Every cistern shall be installed so that it is easily accessible for cleaning or repair. Where a cistern is installed inside a building and, due to limited headroom available, it is fixed with limited clearance from the ceiling or underside of the roof, a quickly detachable fitting must be used to enable it to be easily removed for cleansing and repair.
10. Safe access shall be provided to all cisterns by means of a secure permanent ladder or readily available portable ladder.
PART IV
WATER HEATERS
(L.N. 252 of 1977)
1.
(1) Subject to subparagraph (2), a water heater shall be supplied with water from a cold water storage cistern.
(2) The following types of water heaters may, with the written permission of the Water Authority, be connected direct to a main-
2.
(a) non-pressure type water heaters where no restriction of flow can be effected beyond the inlet control valve;
(b) cistern type water heaters;
(c) instantaneous water heaters where the guaranteed test pressure of the water heater is at least 14 times the static head available at the water heater.
(3) Where a water heater is connected direct to a main--
(a) every draw-off point of the water heater shall be not less than 15 mm above the lowest part of the top edge of the receptacle supplied from the water heater;
(b) if it is a water heater burning gas, the construction of the water heater shall be such that no leakage of gas into the water can occur;
(c) if it is a water heater using electricity, the construction of the water heater shall be according to the relevant British Standards.
Where mixing valves, showers or water blenders are installed, the cold water supply to these fittings shall be from the same cold water storage cistern or main that supplies the water heater and the installation shall be such that the hot water flow will stop before that of the cold water in the event of a failure in the water supply.
3.
Every water heater of the thermal storage type shall be provided with an individual expansion pipe taken from its highest point and shall continuously rise without obstruction until it discharges to atmosphere above the storage cistern at a sufficient height to prevent a constant out-flow of hot water therefrom.
4. No tap or other means of drawing off water (other than a screwed plug with a removable key for emptying the system for cleansing or repair) shall be connected to any part of the hot water system below the top of the hot water cylinder in such a way that the level of the water in the cylinder can be lowered.
5. No tap used for the purpose of drawing hot water shall be fixed at a greater distance (measured along the axis of the pipe by which the tap is supplied) from a water heater or hot water cistern, cylinder or tank, or from a flow and return system, than the distance appropriate to the largest internal diameter of any part of the said pipe as shown in the following table-
TABLE
Largest internal diameter of pipe
(a) Not exceeding 20 mm
(b) Exceeding 20 mm but not exceeding 25 mm
(c) Exceeding 25 mm
Distance in metres
12
8
3
6.
A loose jumper type valve shall be fitted on the inlet of every water heater if a non-return valve is not incorporated in such water heater.