A. Where water or water-using equipment is used with fluids or materials which could contaminate it, there must be adequate protection to stop backflow of potential contaminates into other parts of the system, especially drinking water.
What is it?
Backflow is the term used when fluids travel back towards the source - contrary to the direction which was intended.
How does it happen?
It can happen in one of two ways:
Once fluids are in a water system they can be re-distributed to other parts of the system and in some circumstances back into the public mains.
A. The Water Supply (Water Fittings) Regulations and Scottish Water Byelaws require domestic water supplies to be adequately protected from back flow.
These regulations and byelaws define fluid risk categories by the type of contaminants which may be present, and take into account the risk of harm to human health which may be caused. They also specify appropriate types of prevention devices which must be fitted to guard against backflow.
Backflow prevention devices must be fitted between the domestic plumbing system and the source of the potential contamination.
The table below gives a simple overview of the fluid categories and typical backflow protection devices which could be used.
Fluid category (FC) - Risk to health | Typical device which may be used |
| 1. Drinking water - no risk | No backflow prevention device needed |
| 2. Slight change in taste, odour or temperature - slightly unpleasant | Single check valve |
| 3. Chemicals of low toxicity -slight health hazard | Double check valve |
| 4. Toxic chemicals or carcinogenic substances - significant health hazard | Reduced Pressure Zone (RPZ) valve or break cistern incorporating a Type AF air gap |
| 5. Radioactive or very toxic substances, faecal and pathogenic organisms - serious health hazard | Break cistern incorporating a Type AA or AB air gap |
A. If you're on a meter, a higher than normal bill may mean that there is a leak on one of your pipes or appliances. You can check this yourself in a few simple steps:
1. Turn off all the taps in the house and make sure that there is no water being used.
2. Write down your current meter reading ( find out more about how to take a meter reading)
3. Take a second reading after a few hours, making sure no water has been used in the meantime.
4. Check the meter reading again. If the reading is higher, this means there could be a leak in your home.
If you're not on a meter, signs of a leak could be:
If you have a leak on your supply pipe outside of your home check with your water supplier as they may be able to help repair it. If you think you've a leak inside your property you'll need to contact a qualified plumber. To find a qualified plumber use our search for WIAPS Approved Plumber or use a WaterSafe approved plumbing business.
A. Assuming the worst has happened, and you have found a leak inside your property, the first thing you should do is turn off all stop taps (sometimes called stop cocks or stop valves).
The stop tap controls the water entering your home and is often sited under the kitchen sink, but it depends on where the water supply pipe (or service point) enters the property. Sometimes you will have an additional stop valve in your loft or airing cupboard.
A good tip is to find these stop valves and label them before any plumbing emergencies occur. Try to gently turn them off and back on again. If it won’t budge, don’t force it - you’ll need to get a qualified plumber to replace it.
The next thing you should do is open all cold water taps so that the pipework and storage system drains quickly, this will help to reduce the damage. Do not turn on hot taps (unless the leak is on the hot water). Turn off the central heating system and, if it uses a solid fuel boiler, allow the fire to die out. Switch off any electric immersion heaters, and then call a qualified plumber.
To find a qualified plumber use our search for WIAPS Approved Plumber or use a WaterSafe approved plumbing business.
If you have a leak on your supply pipe outside of your home check with your water supplier as they may be able to help repair it.
A. Cold weather can cause water to freeze. This is a problem because when water freezes in a pipe and turns to ice and expands. As the ice expands, it increases pressure on the pipes and joints, often causing pipes to split or joints to pull apart.
Check all pipes inside your home are lagged and protected before the cold weather comes, and also any bare pipes outside your home. Your local plumbing merchants and DIY stores can help you to find the right insulation. If you're not confident in doing it yourself, a qualified plumber will be able to help you. To find a qualified plumber use our search for WIAPS Approved Plumber or use a WaterSafe approved plumbing business.
You can protect your pipes and fittings from freezing by:
A. Assuming the worst has happened, and you have found a leak inside your property, the first thing you should do is turn off all stop taps (sometimes called stop cocks or stop valves).
The stop tap controls the water entering your home and is often sited under the kitchen sink, but it depends on where the water supply pipe (or service point) enters the property. Sometimes you will have an additional stop valve in your loft or airing cupboard.
A good tip is to find these stop valves and label them before any plumbing emergencies occur. Try to gently turn them off and back on again. If it won’t budge, don’t force it - you’ll need to get a qualified plumber to replace it.
The next thing you should do is open all cold water taps so that the pipework and storage system drains quickly, this will help to reduce the damage. Do not turn on hot taps (unless the leak is on the hot water). Turn off the central heating system and, if it uses a solid fuel boiler, allow the fire to die out. Switch off any electric immersion heaters, and then call a qualified plumber.
To find a qualified plumber use our search for WIAPS Approved Plumber or use a WaterSafe approved plumbing business.
If you have a leak on your supply pipe outside of your home check with your water supplier as they may be able to help repair it.
A. If you can hear noises or banging in the pipes inside your property, likely causes are -
A qualified plumber will be able to help you fix the problem, to find a qualified plumber use our search for WIAPS Approved Plumber or use a WaterSafe approved plumbing business.
A. It's important you know where your internal and external stop taps are (also known as a stop valve or stop cock), as you may need it in an emergency. You should check them every so often or immediately before you start any work on your property to make sure they will shut off the water supply when needed.
Please note that the external stop tap belongs to your local water supplier and you may need to seek permission to operate the external stop tap even in an emergency. If you turn off the external stop tap in an emergency you may need to seek permission from your water supplier to turn the supply back on. Not all water suppliers will give permission to use the external stop tap and if you operate the external stop tap and damage the stop tap, you may be liable for repairs.
How to turn off the stop tap
To shut off the water supply, turn the valve clockwise to close. It may take a few minutes for the water to stop altogether. To turn the water back on, simply turn the valve anti-clockwise. Turn it on and off slowly, never force it. Stop taps aren't used very often, so they can sometimes seize or be very difficult to turn. If you over tighten or use excessive force to operate the stop tap you may damage it.
If it appears to be made of a plastic type material it may only require a quarter of a turn to turn off the water. Normally when the lever is in line with the pipe it is on and when across the pipe off
If your internal stop tap is not turning or shutting off, you'll need to contact a qualified plumber to help to fix this.
If you're having trouble using the external stop tap, it could be that a key is needed to operate it. A universal stop tap key should work for most situations (some water meter housings need a specialist key and you will need to contact your water suppliers if it is not in the meter box), they can be purchased at plumbing merchants. A qualified plumber should also have the tools to operate your external stop tap. To find a qualified plumber use our search for WIAPS Approved Plumber or use a WaterSafe approved plumbing business.
Shared water supplies
Some properties share a water supply pipe and external stop tap. If you're on a shared supply, remember that turning off the external stop tap will shut off the water supply to all the properties on the same supply. You'll need to let your neighbours know before you shut off their supply so that you can complete your work.
Still having problems?
If your plumber can't operate the external stop tap, or you cannot locate it you should contact your local water supplier.
A. Finding internal stop taps
In a home the inside stop tap is usually located under the kitchen sink, but can also be in an airing cupboard or under the floorboards near the front door.
In business premises they are usually located in a service point/cupboard along with the property’s other services as they come into the building or unit.
Finding external stop taps
External stop taps are used to isolate all of the water supply to your home or business. Ideally it should only be used by a qualified plumber or by the water supplier.
Note: the external stop tap normally belongs to your local water supplier and you may need to seek permission to operate the external stop tap even in an emergency. If you turn off the external stop tap in an emergency you may need to seek permission from your water supplier to turn the supply back on. Not all water suppliers will give permission to use the external stop tap and if you operate the external stop tap and damage the stop tap, you may be liable for repairs. So it is worth checking before you need to use it.
The external stop tap is often located near the boundary of the premises under a small cover, about the size of a CD case. If you have a water meter, it will generally be located in the same pit or chamber as the meter.
Many external stop taps are in paths or roads, so you may need to be aware of road traffic and ensure that you do not create a hazard. For example by leaving a stop tap cover open where it may trip up a pedestrian or damage a car.
Shared water supplies
Some properties share a water supply pipe and external stop tap. If you're on a shared supply, remember that turning off the external stop tap will shut off the water supply to all the properties on the same supply. You'll need to let your neighbours know before you shut off their supply so that you can complete your work.
Still having problems?
If your plumber can't operate the external stop tap, or you cannot locate it you should contact your local water supplier.
A. If you're having problems finding or turning off your internal stop tap a qualified plumber can help.
To find a qualified plumber use our search for WIAPS Approved Plumber or use a WaterSafe approved plumbing business.
External stop taps (also known as stop valve or stop cock) can be used to isolate the water supply to your home or business. Ideally it should only be used by a qualified plumber or by the water supplier.
Note: the external stop tap normally belongs to your local water supplier and you may need to seek permission to operate the external stop tap even in an emergency. If you turn off the external stop tap in an emergency you may need to seek permission from your water supplier to turn the supply back on. Not all water suppliers will give permission to use the external stop tap and if you operate the external stop tap and damage the stop tap, you may be liable for repairs. So it is worth checking before you need to use it.
If your plumber has tried all options and you need emergency assistance, you should contact your local water supplier.
Make sure your plumber stays at your property to carry out the internal repairs that may be needed.
A. Your internal stop tap (also known as stop valve or stop cock) is the point where you can shut off the water supply to your home or business. It's important that you check to make sure the tap is working properly every so often, so that in an emergency you can shut off the water supply.
If it's leaking or broken you'll need to contact a qualified plumber to fix it for you. To find a qualified plumber use our search for WIAPS Approved Plumber or use a WaterSafe approved plumbing business.
A. External stop taps (also known as stop valve or stop cock) are used to isolate the water supply to your home or business. Ideally it should only be used by a qualified plumber or by the water supplier.
Note: the external stop tap normally belongs to your local water supplier and you may need to seek permission to operate the external stop tap even in an emergency. If you turn off the external stop tap in an emergency you may need to seek permission from your water supplier to turn the supply back on. Not all water suppliers will give permission to use the external stop tap and if you operate the external stop tap and damage the stop tap, you may be liable for repairs. So it is worth checking before you need to use it.
The external stop tap, is often located near the boundary of the premises under a small cover, about the size of a CD case. If you have a water meter, it will generally be located in the same pit or chamber as the meter. If it appears to be made of a plastic type material it may only require a quarter of a turn to turn off the water. When the lever is in line with the pipe it is on and when across the pipe off.
Some properties share a water supply pipe and external stop tap. If you're on a shared supply, remember that turning off the external stop tap will shut off the water supply to all the properties on the same supply. You'll need to let your neighbours know before you shut off their supply so that you can complete your work.
Many external stop taps are in the path or road, so you may need to be aware of road traffic and ensure that you do not create a hazard. For example by leaving a stop tap cover open where it may trip up a pedestrian or damage a car.
To shut off the water supply, turn the valve clockwise to close. To turn the water back on, simply turn the valve anti-clockwise. Turn it on and off slowly, never force it. if you over tighten or use excessive force to operate the stop tap you may damage it.
If you're having trouble using the stop tap, it could be that a key is needed to operate it. A universal stop tap key should work for most situations (some water meter housings need a specialist key and you will need to contact your water suppliers if it is not in the meter box), they can be purchased at plumbing merchants. A qualified plumber should also have the tools to operate your external stop tap. To find a qualified plumber use our search for WIAPS Approved Plumber or use a WaterSafe approved plumbing business.
Still having problems?
If your plumber can't operate the external stop tap, or you cannot locate it you should contact your local water supplier.
A. If you're unable to work your external stop tap you should contact your local water supplier
Also be very careful if your stop tap chamber is full of debris there may be sharp objects hidden.
Note: the external stop tap normally belongs to your local water supplier and you may need to seek permission to operate the external stop tap even in an emergency. If you turn off the external stop tap in an emergency you may need to seek permission from your water supplier to turn the supply back on. Not all water suppliers will give permission to use the external stop tap and if you operate the external stop tap and damage the stop tap, you may be liable for repairs. So it is worth checking before you need to use it.
A. Water pressure within the home can vary based upon the location, time of day, type and height of the property, as well as the type of appliances used and how much water is being used by other customers.
Pressure is normally higher late at night when very little water is used and most people's taps are turned off. In the morning when people are taking a bath or shower, or watering their garden on a hot evening, there is a bigger demand for water which can cause lower pressure.
Water suppliers’ statutory reference level of service for mains water pressure is ten metres head of pressure (or one bar) with a flow of nine litres a minute. This means there is enough force/pressure to push the water to a height of ten metres.
This is measured at the point where the water leaves the water suppliers’ pipework and enters yours (usually at the outside stop valve or property boundary).
As a guide, if you have a suitable single service pipe, the first tap in the home (this is usually the kitchen tap) should be able to fill a 4.5 litre (one gallon) bucket in 30 seconds, with all other taps and appliances turned off. Another way of putting it, enough water pressure to fill a cold water storage cistern in the roof space of a two story house.
It is possible to make changes to your internal plumbing to improve your water flow. For example by ensuring your stop tap is fully open. You could also check that any systems that depend on the supply pressure are set to the statutory minimum level of 1 bar/10 metres head.
For further help and advice you should contact your water supplier.
A. Maximum
There is no legal requirement in respect of the maximum supply pressure. Where the supply pressure exceeds the maximum working pressure of fittings it is the customer's responsibility to install a suitable pressure reducing valve or change the fittings for ones suitable for the existing supply pressure.
Minimum
The minimum pressure requirements as set out in the Water industry Act (1991), Water (Scotland) Act 1980 and Water and Sewerage Services (Northern Ireland) Order 2006, is that needed to supply the top-most storey of every building within the undertaker's area of supply. However, the water supplier is not required to deliver water at a height greater than that to which it will flow by gravitation through the existing water mains from the service reservoir or tank from which the supply is taken.
A. So far as is reasonably practical the temperature of water within cold water pipes should not be warmed above 20°C.
A. Defra’s guidance states that hot water should be stored at a temperature of not less than 60°C and distributed at a temperature of not less than 55°C. This water distribution temperature may not be achievable where hot water is provided by instantaneous or combination boilers.
Where practicable it should also reach your tap and be at least 50°C within 30 seconds after fully opening the tap. This criteria may not be achievable where hot water is provided by instantaneous or combination boilers.
