PLUMBING Presentation on Installation of a Domestic Cold

PLUMBING Presentation on Installation of a Domestic Cold Water Storage Cistern

Cold water Supply At the end of this part you should be able to : • State the requirements of pipes and fittings used in cold water systems. • Explain the requirements of protecting systems against frost damage.

Cold water – Health & Safety - Working in loft spaces • Cat boards are used to provide a safe area to walk and work on. • There is adequate ventilation. • There is adequate lighting to be able to work safely. • You have fire extinguishing equipment to hand. • You have a safe means of exiting the roof in an emergency. • If roof insulation is to be laid a protective mask must be worn.

Cold water – Health & Safety - Working in loft spaces If working in existing or old roof spaces you should also: • Ensure you remove any old lagging to pipework is being altered and requires jointing with soldered fittings, many older types of pipe insulation are highly flammable. • Take care if old electric cables are in the work vicinity or are to be handled • Check for wasps or bees nests in the loft area. • Be on the look for vermin (Weal's disease).

Cold water – Storage cistern requirements The cisterns are available in square, rectangular or circular shapes, and are produced in black to prevent algae growth. Because of their flexible material the base of the cistern MUST be fully supported and we shall look at the requirements for this next. (Case study p 34 in handout)

Cold water– Storage cistern requirements – Construction of a cistern stand Storage cistern are usually located in the attic space, their installation has to meet the requirements of the Water Regulations. Base bearer to span MINIMUM of three joists Check for level Deck Good practice to place sound proofing material, it also helps protect base of cistern against any sharp objects Stand legs Roof joists Brace Ceiling Loft insulation

Cold water – Storage cistern requirements – Construction of a cistern stand If the cistern is to be laid on top of roof joists insulation can be removed to help protect cistern from frost damage.

Cold water – Storage cistern requirements – Construction of a cistern stand Cistern base should span additional joists to help spread the weight of water being carried. Timber or ply base should be used for the cistern base. Chipboard must never be used as this is prone to disintegrate if it becomes damp.

Cold water – Storage cistern requirements – Construction of a cistern stand Mark cistern float valve, overflow and outlet points. Drill holes and fit valves and fittings. Ensure swarf and debris are removed from inside the cistern. Do not use oil based jointing compounds to make cistern connections as this can cause contamination to the water and may also react with some types of plastic storage cisterns. Connect pipework. Fill and test.

Cold water – Storage cistern installation requirements Cold water storage cistern cannot be installed any old how A drill used with proper hole cutters should be used NOT a heated piece of pipe

Cold water – Storage cistern installation requirements Compression outlet connector, available in various sizes. PTFE thread tape can be used IF required. No oil based jointing compound should be used. STORAGE CISTERN Two plastic washers are used to seal the outlet connector to the cistern. Washers go here

Cold water – Storage cistern installation requirements – pipework connections SIDE OUTLETS 25 mm to prevent debris entering pipework 25 mm BOTTOM OUTLETS 25 mm to prevent debris entering pipework 25 mm

Cold water – Storage cistern requirements – Installation of cistern Insulation jacket Float operated valve Service maintenance valve Vent Rubber grommet to seal open vent from cylinder Close fitting lid Overflow with dip pipe fitted a min 25 mm below level of float valve Cold feed to cylinder 25 mm from bottom of cistern Rising main Cold feed top cylinder in A/C

Cold water – Storage cistern requirements – Installation of cistern Installation kit Service valve Insulation jacket Cistern lid Float operated valve Cistern

Cold water – Storage cistern installation requirements – pipework connections Warning & Overflow pipes • Combined warning and overflow pipe with cisterns of 1000 litres or less • More than 1000 litres and a separate warning pipe is required 25 mm min Screened overflow connection 50 mm min Overflow pipe

Cold water – Storage cistern installation requirements – pipework connections It has to be stressed that there is a fundamental difference between a Warning Pipe and an Overflow Pipe: A Warning Pipe This is a smaller diameter pipe used to warn of an impending overflow. It is connected to the cistern lower than the Overflow Pipe This is designed to take the discharge from the cistern when the inlet valve is running full bore and prevent the inlet valve from becoming submerged. Both pipes to have screened outlets and terminate conspicuously preferably outside. Storage cisterns to have separate warning / overflow pipes from feed and expansion cisterns used for central heating.

Cold water – Storage cistern installation requirements – pipework connections Warning & Overflow pipe on cistern capacity over 1000 litres 50 mm 25 mm 50 mm

Cold water – Storage cistern installation requirements – pipework connections Feed to Domestic Cold Water Domestic Hot Water Cold Feed (indirect) • If cistern supplies both hot and cold water supplies outlets must be positioned so that the hot water supply will run out before the cold …. Why ?

Cold water – Storage cistern requirements – Installation of cistern Incorrect pipework positioning for rising main. . Why ? AIRING CUPBOARD

Cold water – Storage cistern requirements – Installation of cistern Correct pipework positioning AIRING CUPBOARD

Cold water – Storage cistern requirements – Installation of cistern Overflow pipes must be suitable to carry the water temperature that may discharge through them. For example cisterns for solid fuel heating which may discharge boiling water should only be installed in copper. Overflow must be one size larger than the supply it protects with the minimum size 22 mm. Must have a suitable fall to the discharge point and be well supported.

Cold water – Storage cistern requirements – Installation of cistern Water Regulations state 350 mm minimum distance Make sure that storage cisterns and pipework meet the minimum distances required by regulations, to prevent frost damage and allow servicing of cisterns.

Cold water – Storage cistern requirements – Installation of cistern STRAIGHT SERVICE VALVE FITTED TO BALLVALVE BENT SERVICE VALVE FITTED TO BALLVALVE GATE VALVE FITTED TO CISTERN COLD WATER SUPPLY OUTLET

Cold water – Storage cistern requirements – Installation of cistern When the system has been filled and tested for leaks, water levels and performance the system should be flushed and cleaned. Fit pipe and cistern insulation and labelling to valves. DHWS CFE VALVE CLOSE TO TURN OFF HOT WATER SUPPLY

Cold water – Storage cistern requirements – Installation of cistern Work book time