Water Hammer - Upstairs water pressure faster than downstairs

[Arctic]

Hi,I changed the washers in my upstairs bathroom sink taps a couple of weeks ago and ever since I have been unable to use both taps (hot and cold) in the bathroom as there is a terrible hammer vibration/ shake coming from both whenever they are turned on.It is only affecting this one set of taps (at the same time of changing these washers, I changed the washers in my downstairs kitchen taps, which are fine since).I have turned the water stopcock off and then turning the downstairs kitchen tap on full, followed by a 1/4 1/2 turn of the stopcock to get a normal steady flow downstairs. Despite the pressure being normal downstairs, the water pressure upstairs is extremely fast.


If I turn the pressure right down at the stopcock (one quarter turn), then the flow is trickling out downstairs, which is impossible to live with, but the flow upstairs is then normal and the water hammer disappears...!


Any ideas how this can be resolved?.
Thanks in anticipation

 

[rpm]

Welcome to the forum Arctic, was there isolation valves on the pipes to the taps and are they now in the same postion as before?

 

[Best]

Sometimes turning the stopcock down will actually cause water hammer! Also the washer in the stopcock can be faulty - too hard or enlarged.
Turn it up full and turn any isolating valves on the offending taps down a bit.
I am wondering have you incorrect size of washers on that tap, or perhaps too soft?
You might need a pressure reducing valve fitted on your incoming water mains.

 

[Arctic]

Thanks for quick replies. The house is a new build, around 12 years old so there are no isolating valves on any of the plumb works - probably a cost saving exercise...

I didn't realise the washers came in different strengths and had replaced the taps in the kitchen and upstairs bathroom with the same 1/2 inch rubber washers that i bought from B&Q...

Are there different types or are all 1/2 inch washers for taps the same?

 

[Arctic]

Just checked the washers that I used for both the taps in the kitchen and the bathroom were ALTECH 1/2 inch Delta Tap Washers

 

[Best]

A lot of taps now have the smaller 3/8" size washers.
Some washers are different softness. I would have thought your B&Q washers would be okay if correct size.
Strange one! I have seen water hammer due to simply the tap washer.

 

[Arctic]

The washers appear to be the right size. Saying that, there was no water hammer before I changed the washers so it has to be either that or the water pressure. I may take the valve off and take it to a plumb centre tomorrow and ask them for the right washer for the valve? Probably worth a shot.

 

[Best]

I really can't see a reason that you have water hammer after just replacing washers.
Any air in pipes would clear quickly on mains pressure.