Do I need a check valve on the cold water supply to my washing machine ?

Question

I have a washing machine connected to the cold water supply and I have noticed that there is no check (non return) valve installed. Do I need this or is it just a precaution. Also, does the supply to the outside tap need one too?

Many thanks

Answer 1

the water regulations state that washing machines, if they are approved as in the water materials and fittings directory, are already fitted with backflow prevention ie a check valve so NO one is not needed

garden taps fitted before 1999 can be fitted with a double check vale inside the house, or use a tap that has a double check valve incorporated into it, or use a hose union backflow prventer (type HA) or a double check valve after the tap outlet.

a new install needs an isolator and double check valve inside the house other stuff to consider as well

Answer 2

Not normally needed. They are only necesssary where there is risk of contamination of the water supply from the hot water supply or from foul water, eg bidet. That said it doesn't hurt especially if there is any risk of back siphonage on the waste side. Most outside tap installations I have seen don't have them. But you should have a shut off valve (remember to drain off when you use it) to stop the valve and pipework outside freezing in winter.

Answer 3

outside does and it is good practice for the washing machine to be controled by the appropriate washing machine tap . do you mean non return valve or tap or gate valve .

Answer 4

washer  no

outside good idea

Answer 5

Yes you do. No it's not a precaution & yes you do!!

Answer 6

You don't need one on either, I never bother with mine, they are a waste of time.

Answer 7

Doesn't NEED either. However some people have them for peace of mind.

Answer 8

washer doesn't need one, but I think the outside tap's covered by water byelaws & must have one.

Answer 9

Under Water Company Bylaws in the UK you should fit a double check valve on both the washing machine cold connection and also on the outside tap. These are readily obtainable and are also available as a combined double check valve and hose union bib tap for outside. The outside tap should also be provided with an internal stop valve and draincock to prevent the tap freezing in the winter. Any other connections to the mains water where contaminated water could be drawn into the drinking water system should also be provided with a double check valve.

Answer 10

I've never heard of the check valve saving the day; but having said that - I have one on mine.  I view it like a safety belt - you may never need it - but if its called for once in a lifetime, it's earned its keep.

Answer 11

If a check valve is used at all would be on incoming main water supply line and used to prevent the water from being sucked from water heater in the event of a loss of water from system to prevent damage to electric water heaters and draining the inside pipes. Up to you but 1 at entry is all that is needed.