Unable to isolate water supples to power shower

[paull123]

Hi
Can anyone please help? I am trying to isolate the hot and cold water supplies to my Aqualisa power shower in order to change the noisy pump. I have located the the marked up gate valves which are marked up "hot and cold shower" in the airing cupboard, turned them both off but the water flow to the shower remains on even after about 5 mins draining. The house is about 7 years old so could both valves be not closing properly?
Any help really appreciated.

 

[seco services]

if they are gate valves more likely they are passing change them to full bore lever valves.

if the hot is passing then try shutting the gate valve that supplies the cylinder from the loft tank.
should be just above the cylinder on the pipe that feeds to the base of the cylinder.
or bung the supply pipe in the loft tank.

then you can change them cra**y gate valves for lever valves.

 

[kevplumb]

then you can change them cra**y gate valves for lever valves.

full bore of course

 

[paull123]

Thanks for that, are lever valves the same size fitting as gate valves?

 

[gasbanni]

Yes should be 15mm compression, turn the water off at the stop tap open all taps and wait for it to stop, flush the loo. there may be some water in the pump but look out for it as you remove the gate valves. v easy.