Cold Water Pressure Problem - ideas please!

[dontknowitall]

My turn to ask a question ... cold tap on bath and wc inlet valve are giving useless water flow and pressure. Problem started a couple of weeks ago and no work done in house recently. I just want some ideas as to how to tackle this issue.

Stop tap downstairs, feeds kitchen tap and is tee'd off to cwss in loft.

Kitchen tap pressure is fine, as is ball valve on cwss and so are hot water taps in the house.

CWSS feeds hot water cylinder (downstairs) and also feeds bathroom (which is also downstairs next to hot water cylinder). No other water supplies in the house. The cold water pipe in the loft falls on the horizontal runs in the loft and then drops around 7 meters vertically downstairs (behind boxing).

The wc and cold bath tap in the bathroom are only outlets affected. The basin seems to be unaffected (strange?). I think the pipes drop in the corner of the room, run along at skirting board level, tee to feed the basin, tee to fee the wc then the bath.

There's a gate valve in the loft which supplies the cold to the bathroom.

What to do ...???

I've turned the loft gate valve with the taps in both open and shut positions, to no effect.

I'm due to return to the house but would be grateful for some ideas. My first thoughts are to drain the cwss, undo the cold pipes in the loft and use a wet vaccuum to try and stuck stuff out (e.g. blockage).

Next would be to undo some of the boxing and see if I can open the pipes in the bathroom.

Any other ideas and what would you look for? Please excuse the long post but hopefully you'll be able to understand the layout without asking loads of questions.

 

[SimonG]

Is basin on mains, had one last week, bath and wc on tank, basin on mains.

Bit of insulation in pipe? Something in the tank conn?

 

[dontknowitall]

Basin on cwss. Could be insulation in pipe or wasps in the tank connection (wasp nest recently removed).

By the way, cronic "installation" of loft insulation done back in March. Explained frozen pipe and electric wire fire risk to customer - she wasn't pleased. What else do you expect from Domestic and General? Charged £200 for one man for a couple of hours of work!!

 

[WaterTight]

Can't you backfill it on mains somehow?

 

[SimonG]

Sounds like a bit of both, a well insulated wasp!

 

[dontknowitall]

Can't you backfill it on mains somehow?

Great idea!! Many thanks for that one.

 

[WaterTight]

although that might just shift the problem elsewhere

 

[WaterTight]

Or disconnect either/both affected supplies and attatch a hose to supply pipe and run it into the bath, see if something comes out.

 

[GQuigley67]

i would try the wet vac

 

[dontknowitall]

4 weeks since this started? Blimey - talk about the rapid response team from DKIA Plumbing and Heating Corporation.

Went to do this job today. Found a flexi under a basin, undid it and loads of black bits came out (bit like wasp abdomens). Tap cleared and all hunky dory. Did the same for the cold. Then the WC. Then the bath taps. Happy customer and happy me cos I got paid.

Only thing I can think of is the monkeys/cowboys from whichever company had installed loft insulation and a wasp nest had to be destroyed. In fairness to them they lagged the pipes well and put loads of rockwool down - shame there's a gaping hole into next door's loft but there we go.

Many thanks, again for the suggestions.