Plumbing Practical Guide - Plumbing emergencies.pdf
Post on 20-Jul-2016
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Plumbing emergencies What to do if: Water pours from the loft
1 Turn the main stoptap/ stopcock off (clockwise). It is usually close to the kitchen sink (if you cant, see pic 3.) Put buckets under the leaks, then turn on all the cold taps in the house and flush all the WCs to drain the cold-water storage cistern. 2 Find the cause of the trouble. It may be a burst pipe in the loft or a cistern overflow caused by a blocked overflow pipe. No water comes from a tap 1 If no water flows from the kitchen sink cols tap, check that the main stoptap is open. If it is, call your water supply company. You will find the number under Water in the phone book.
2 If no water flows from other taps, check the cold-water cistern. It may have emptied because of a jammed ballvalve.
If it is empty, move the float arm sharply up and down to free the valve, then clean the valve. Alternatively in frosty weather there may be an ice plug blocking a supply pipe. If the kitchen cold tap is working, check the flow into the cold-water cistern by pressing down the ballvalve. If there is no overflow, the rising main is frozen, probably between the ceiling and the cistern outlet. 3 If the cistern is filling, check the bathroom taps. If there is no flow from one tap, its supply pipe from the cistern is frozen. 4 To thaw a pipe, strip off any lagging from the affected part and apply hot water bottles. If a pipe is difficult to get at, blow warm air onto it with a hair dryer. Warning Do not use a blowtorch to defrost a frozen pipe. It may cause a fire, or melt the solder in a pipe joint and cause another leak. Hot water cylinder leaks
1 Turn off the gatevalve (clockwise) on the supply pipe from the cold-water cistern to the hot water cylinder. If there is no gatevalve, turn off the main stoptap and turn on all the taps to empty the cistern. (This will not empty the hot water cylinder, but will stop water from flowing into it). 2 Switch off the immersion heater, if there is one. 3 Switch off the boiler, or put out the boiler fire. 4 Connect a hose to the cylinder drain valve, which is located near the base of the cylinder where the supply pipe from the water cistern enters. Put the other end of the hose into an outside drain.
5 Open up the drain valve with a drain valve key or pliers. 6 Get the hot water cylinder repaired or replaced by a plumber. You cannot turn off the water If you cannot turn off the water at the main stoptap, tie up the float arm in the cold-water cistern to stop it filling, turn on all the taps (except the kitchen cold tap) and flush the WCs. You can then work on the problem pipe. To work on the rising main, locate the outdoor stoptap (page?). Use a stoptap key (available from plumbers merchants) to turn off the tap and cut off the mains supply to the house. How water is supplied to the home Whether for home improvements, or for tackling emergencies, it is important to know what type of water system you have, and where to find all the relevant system controls. The cold water supply There are two types of cold water supply in UK homes: direct cold water supply, branch pipes from the rising main lead directly to all the cold taps and WC cisterns in the house. This means that you can drink cold water from any tap. A pipe from the rising main will usually feed a storage cistern in the loft the reservoir that feeds the hot water cylinder. A direct cold water system is simpler and cheaper to install than an indirect system. BE PREPARED Make sure that you and others in the house know where the indoor and outdoor stoptaps are located, as well as the gatevalves on the supply pipes to the hot water cylinders and cold taps, and label them.
Most UK homes have an indirect system. The rising main feeds the cold tap at the kitchen sink (and possibly pipes to a washing machine and an outside tap). This water is clean drinking water. It then continues up to a cold-water storage tank in the roof, which supplies all other taps, the WCs and the hot water cylinder. There are advantages to an indirect system: water from a cold water storage cistern gives even water pressure, which produces quieter plumbing and less wear and tear on washers and valves. Leaks are also less likely, and any leak that does occur will be less damaging than one from a pipe under mains pressure. Water from a cistern is warmer than mains water, so less hot water is needed for washing and bathing. It also reduces condensation on WC cisterns. And if the house supply is temporarily cut off for work on the mains, for example- there is a supply of stored water available for use. SAFETY NOTE If your house has an indirect system, do not drink water from any tap other than the kitchen one. Water from a tank may not be clean.
1 Water mains 2 Communication pipe The water supply to most British From the mains, a pipe known homes is provided by the local as a communication pipe takes water supply company, through the water to the water companys iron or heavy plastic water mains. stoptap a control valve about 1 m below the ground at or near the boundary of each property.
3 Outdoor stoptap 4 Service pipe The stoptap, which is turned with From the water companys a big long key, is at the bottom of stoptap, a service pipe carries of an earthenware guard pipe water into the house. The pipe under a small metal cover, set into should meander slightly in the surface of the garden or the the trench to allow for ground public footpath outside. In older movement, which would other- properties, this may be the only wise pull on the fittings at each place where the water can be end. To avoid frost damage, turned off. it should be at least 750mm and not more than 1.35m below ground. 5 Rising main The service pipe enters the house, usually close to the garden sink (but sometimes under the stairs or in a garage), and from there is known as the rising main. Another stoptap for cutting off the house water supply should be fitted where the pipe enters the house. The rising main is usually a 15mm diameter pipe, but in areas where mains pressure is low, a 22mm diameter pipe is used. HOT WATER SUPPLY There are two basic hot water systems: either indirect, with all hot taps supplied from a hot water storage cylinder, or direct, where cold water is heated on demand. The latter is usual when all the cold water supplies come direct from the rising main. Back boilers and separate kitchen boilers have largely been replaced by modern boilers that supply both hot water and central heating. Instantaneous hot water systems Single point water heaters may be heated by gas or electricity and are usually sited next to the point they serve. In the case of electric heaters, such as an electric shower, they must be wired to the mains via an isolating switch. Many homes are now being fitted with multipoint water heaters most commonly combination (combi) boilers. A combi boiler combines the functions of a central heating boiler and an instantaneous multipoint water heater.
Indirect systems You can identify an indirect system by the two water tanks in the loft. The second, smaller one has a vent pipe over the top. This is called a header tank, or feed and expansion tank; it keeps the primary circuit topped up. The level of water in the header tank is low enough to allow the water to rise above as it expands when it gets hot without overflowing. The primary circuit With an indirect water system, the hot water cylinder contains a coil of pipe, which forms part of a run of pipework attached to the boiler. This is heated directly by the boiler. Indirectly, it heats the water in the cylinder. The coil, or heat exchanger, is actually part of the central heating circuit: its water heating function arises out of its main job, which is to heat the radiators. This heating pipework is known as the primary circuit and the pipes that run to and from the boiler are known as the primary flow and return. Primary circuit water constantly circulates while the boiler is on. The hot water tank itself works in the same way as one in a direct system. The secondary circuit Water in the hot water cylinder is supplied from the cold-water cistern, which keeps the cylinder constantly topped up as hot water is used. A vent pipe from the top of the hot water cylinder hangs over the cold-water cistern, allowing air to escape. Pipes to the hot taps lead from the vent pipe. Because these branch pipes leave above the cylinder top, the cylinder cannot be drained through the hot taps. This means you dont need to turn off the boiler if the household water supply is temporary cut off. This system is known as a vented system. It is open to atmospheric pressure and operates under low pressure. A pump can be fitted to boost flow to showers or taps. Unvented (sealed) got water systems This system is the same as the indirect system, except that it is connected to the mains. This gives mains water pressure to hot taps and showers. Many safety features are built into this type of system to allow for the greater pressure and expansion of the water. No cold water storage cistern or header tank is needed, so there is no pipework in the loft. Direct systems In older houses with a direct system (often back boilers or solid-fuel boilers), the water is heated directly by circulation through the boiler. Water is fed from the cold-water cistern into the bottom of the cylinder and then to the boiler. The flow pipe from the top of the boiler discharges hot water directly into the top of the cylinder, forcing colder, denser water at the bottom through the return pipe back to the boiler. The hottest water, being the lightest, is always at the top ready to be drawn off.