Shower doesn't work after refilling cold water storage tank

[405 TD Estate]

I was boarding the loft out and emptied the cold water storage tank to make it lighter so i could get the boards underneath.

I did this by turning the cold water to the house off and running water out the bath. Later turning the cold water on allowed the tank to fill as normal.

This morning the shower didn't work at all to start with, but the bath and sink taps did although not as much water as normal came out, as if there's less pressure. Puttign the shower in the bottom of the bath and running it improved things a bit but it's still poor - any ideas?

I think it may be trapped air but how would that stop the shower working and how do I get it out?

The tank is filling normally.

[Andy Burns]

Sucking and/or blowing through the bath taps may dislodge any airlock, if that fails, temporarily connect a hosepipe from a mains-fed tap into the tank-fed one(s) and give them a quick squirt.

[AlanC]

Could be some crap from the bottom of the tank was sucked down the pipe when you emptied it. Same procedure for clearing an airlock might cure it.

Is it OK to board under the cold water storage tank? I thought that this area was normally left clear (no insulation etc) to allow some wamth from the house to keep the water from freezing.

Alan

[Paul Matthews]

Probably an airlock as you suspect. Why would it stop the shower working? I don't know your plumbing, but if it is anything like mine the storage tank is in the loft and the hot water cylinder is upstairs.

There are then options for how the plumbing goes - do you know where the feed pipes run for the shower? If they loop up such that there is a high point, especially if that high point is close to the storage tank, you may just not have enough water pressure to get past the air - think syphon.

How to sort?

You could shut the water off again, drain again and fit bleed valves at the high points, but that is a lot of work,

I would go with Andy - use mains pressure cold water to blow the air back through the plumbing. I used to get airlocks regularly in my old house, and managed to perfect a grip on the mixer tap in the kitchen where I could seal round the tap with my hand, but I left speace between the hot and cold outlets. Opening both hot and cold blew the air back. Job done.

A shower may be more awkward!

[Dave Baker]

What sort of shower? A completely separate one from the bath or do you just mean one that's part of the bath taps?

but the bath

Probably crap from the bottom of the loft tank has partially blocked the pipes. Old tanks get a layer of sediment and limescale in them and you might have washed chunks of this into the outlet. If you connect a mains cold tap to the affected taps or shower with a hose you might be able to blow the crap back up into the loft tank.

Might be worth draining the loft tank again and cleaning it out too.

[405 TD Estate]

Yes the feed for the shower goes straight upto the loft and I guess loops round since the tank must feed it. I will try connecting the shower hose to the mains cold water to back-fill the pipes as it were.

There was insulation all under the tank before I boarded out the loft

- it's so breezy up there and the tank is on a tall stand so that i can't see any heat rising from the floor keeping the water warm. The tank has an insulating jacket on it.