Loss of water pressure after installing isolating valves

[eroberts]

Hi, Last weekend we ripped out our old bathroom (bath, basin, wc) and cloakroom (wc, basin).

First we tried to turn off the supply from the cold water tank to the cold taps by closing the gate valve. This wouldn't budge and the spindle actually snapped off - great - but no leaks so we weren't too concerned. We turned off the gate valve from the cold water tank to the hot water tank and the mains stopcock and drained the system - all good so far!

We then followed the advice of our DIY books and fitted isolating valves to all the hot and cold water feeds (8 in total) and then turned the water back on.

So far we've fitted a new bath with a mixer / shower tap but what used to be pretty good pressure is now dismal. We thought it was the fault of the new tap except for the fact that we also have a separate shower fed with its own supply from the hot water tank and cold water tank. The pressure of the shower has also dropped very noticeably.

We have no idea if when we've fitted the new wcs and basins, any air locks or debris in the pipes will clear and all will be well - seems strange that it's affected a sepately plumbed shower though.

I would really appreciate any suggestions - thanks in advance!

 

[ogoshi]

First thing to check is that the gate valve which you closed is now fully open.second,are the isolating valves fitted the right way round,most have an arrow showing correct direction,as inside one end is narrower than the other.third,are the isolating valves fully open,ie..screwdriver slot fully in line with the pipes.Fourth,is the mains stopcock fully open.
finally,most new bath taps(that are supplied with the suite) have 3/4" tails,but 1/2" seatings which reduce the flow greatly.

 

[eroberts]

Hiya, First thanks for the advice. After lots of faffing we eventually discovered that our new taps have a water saving device which reduces pressure!

 

[catnipsta]

Hi eroberts

You mentioned that you had a water saving device on the taps that you had installed. Could you please tell me what exactly that is? This is because I have the same problem after only fitting new mixer taps for the kitchen and the bath...I have not added any isolation valves.

 

[westbrook]

Isolating valves do have a smaller bore and do reduce flow rate. As do the flexi hoses that are now commonly connected to bath and basin taps.
Solution... Change the isolating valves for *** ( water or gas) fittings as they are the full 15 or 22mm bore.