Installing an outside tap: Washing machine waste outlet

The first step is to remove the washing machine and tumble dryer. To do this you will need to isolate the hot and cold water supplies to the machine.

Note, the red and blue levers for hot and cold, the red is in the on position and the blue is off. Take care as the washing machine isolation valves may be faulty and the red and blue levers may be simply turning on their spindles and not operating the valve correctly.

Carefully pull out the machine keeping an eye on the flexible hoses to ensure they are not stretched or damaged in any way. Once the connections are accessible at the rear of the machine slowly loosen the connections carefully one at a time. Have a cloth ready to catch any water wriggle the hose connection but ensure that the threaded nut remains attached to the machine until you are sure that the water supply has been isolated. If water gushes for more than a few seconds, out then you must assume that the washing machine isolation valves are faulty and you will need to isolate them further back by turning off the mains stopcock and draining down.

Having removed the washing machine there is now a clear area to work in. In this case the washing machine isolation valves were working and so the mains water supply does not need to be turned off. With the washing machine removed, in our case you can see how the washing machine waste outlet had been simply looped over an un-trapped vertical waste pipe outlet. In effect this is an open drain, which means that foul smells from the drainage system simply rise up the pipe into the room. Even if the pipe was capped foul smells could still enter the room via the washing machine itself. This is a serious health hazard and needed to be remedied immediately by installing a suitable waste trap.

Traditionally, a water seal trap or 'U' bend is used in waste systems to prevent foul air from the drains entering dwelling spaces. However, these traps must be installed in line with strict criteria if they are to function effectively. They are also subject to various problems, such as siphonage and evaporation, which can deplete the water in the trap, rendering it ineffective.

Hepworth's Hep vO hygienic self-sealing waste valve effectively overcomes these problems and does not rely on the water seal principal. It takes the form of a slim tube containing a purpose-designed membrane. The membrane within the valve opens to allow water to flow through it but closes to create an air tight seal when the flow ceases.

The valve can be fitted either directly to plumbing appliance's such as a wash hand basins, showers, baths etc and they can be fitted horizontally or vertically. This opens up new installation opportunities, provides design versatility and brings space savings.

In the case of appliances such as washing machines and dishwashers an in line adapter is available.

In this example the Hep vO valve will be mounted in the vertical position using a 'running adapter' to make both ends of the valve in line pipe connectors.

Cut the pipe approximately six inches above the swept Tee so that the Hep vO valve can be positioned above it.

Disassemble the connectors and push the cap and sealing rings over the vertical pipe. Push the Hep vO valve onto the pipe making sure that you have full depth insertion, then screw the cap shut to make an effective seal.

Repeat the operation for the top connection using the piece of pipe that was previously cut off, make sure there is sufficient height for the washing machine hose to loop over without touching the internal self-sealing waste valve.

Secure the assembly back to the wall with suitable pipe brackets, and loop the washing machine hose back over the vertical pipe. The waste pipe is now effectively sealed preventing foul smells from entering the room.

The task was simplified by using the Hep vO valve and 'running adapter'