Reduced flow to cold bath tap - worried about back flushing

[cotswolds]

My partner has recently had a problem with slow water flow to the cold bath tap in her house (which she now rents out). I dismantled all the pipework close to the tap and found what looked like soggy loft insulation in the base of the tap and behind the aerator. Removing this has not solved the problem.

Pipework is as shown. Flow to hot taps is normal, so the blockage is probably in the elbow that connects copper to plastic, or maybe in the curving plastic pipe that goes under the floorboards, the branch exit from the tee or the short section of pipe to the elbow.

pipework

• cotswolds
• 4 Oct 2013
• 1

I know how to back flush from the bathroom, but I’m worried that if I do that, the blockage will go the wrong way at the tee and end up in the hot cylinder and affect a lot more taps.

Access at the bathroom end is good, but very difficult in the airing cupboard. The elbow is almost behind the hot water cylinder, and there’s a shower pump and associated pipework (with separate cold feed) filling the space at the side of the cylinder. Accessing the tee/elbow near the bottom of the airing cupboard might be possible, but catching any water if I try and backflush to there would be near impossible.

What’s the professional way to tackle this? I’m on the verge of getting a plumber in, something I’ve never done before (other than for gas).

 

[footprints]

Proper way is cut out the pipe as you no doubt guessed, I suspect there will be debris in the hot cylinder already it's just laying on the bottom of the cylinder and with luck may stay there.

 

[HERTS P&D]

Have you checked the tap spout?

Andy

 

[cotswolds]

Proper way is cut out the pipe as you no doubt guessed, I suspect there will be debris in the hot cylinder already it's just laying on the bottom of the cylinder and with luck may stay there.

I wondered if a plumber would use a pipe freezing kit, which would have the advantage of not having to drain the tank as well, but don't know if that's possible in the available space.

Drawing the diagram has made me realize how few places the blockage can be, so I've decided to try and dismantle the bits I haven't yet done. The elbow and the tee are compression, think I can get them undone and clear them. Then treat the plastic pipe as conduit and poke some 2.5mm T&E back along from the bathroom. Can't see why that won't work, and seems more controlled than back flushing.

Thanks for your help.

 

[Burnerman]

I'd be inclined to turn the water supply off to the loft tank by holding up the ball valve with some string, draining both the tank and the copper cylinder and then disconnecting the 22mm plastic pipe run and work from there.....its probably the only way to get the debris completely out.
You could probably cobble up some method of connecting the cold mains to the bath tap and back flush from that end.
John

 

[cotswolds]

Have you checked the tap spout?

Andy

Think I blew through it after clearing the aerator, but I'll double check next time I dismantle, thanks.

 

[mickthegas]

check the main tank,some of the insulation on the main tank might have fallen in, had this before