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DJM

Recently the cold supply to bathroom from tank lost pressure. Air lock I thought, so try the usual trick of connecting a hose with mains pressure to the affected tap. Result success - well for about a week then pressure drops off again. Repeat mains hose trick and : Success - well for a bout a week again. Played this game for a bout a month now and am getting fed up.

I can't see any leaks, the hot supply pressure remains the same all the time. Both come from the same loft tank, albeit from different supply lines. so the head of water is the same.

I am confused

. Any suggestions for reasons or remedies.

Ian · Moderator Joined: 18 Feb 2003 Posts: 32 Location: wigan

DJM · Posted: Tue Feb 25, 2003 9:06 am Post subject:

Thanks for your reply

There is a single cold water tank in the loft. Seperate feeds from the tank to support hot and cold water.

First from tank to hot water cylinder and then to bathroom upstairs and wc, kitchen and utility room downstairs.

second from tank to feed cold only the bathroom upstairs (basin, shower, wc, bidet, bath). There are some residual pipes which are capped off running to other rooms where old basins were removed before we bought the property. Mixture of copper and polypipe.

System has been working fine for the past 4 years, and has only recently started playing up. Hot water pressure seems fine, it's only the cold which is not. Had the mains hose attached in bathroom last night and the pressure is fine again, but I expect this to change by next week. All cold outlets are affected in bathroom.

hope you have some ideas, because I am stuck.

DJM · Posted: Tue Feb 25, 2003 9:08 am Post subject:

sorry, forgot to say that the hot temp has remained static. No fluctuations in temp or pressure.

Ian · Moderator Joined: 18 Feb 2003 Posts: 32 Location: wigan

DJM · Posted: Tue Feb 25, 2003 1:24 pm Post subject:

Ian,

thanks for the response.

Ian · Moderator Joined: 18 Feb 2003 Posts: 32 Location: wigan

DJM · Posted: Wed Feb 26, 2003 2:46 pm Post subject:

thanks once again for the response. Smile

ChrisR · Posted: Fri Feb 28, 2003 8:15 am Post subject:

I wonder why the need is felt to requote all the text which is available on the same screen?? I shall not.

Have you had a good look in the cistern for any material which could get sucked down into the pipe, to be ejected when you reverse the flow? I have known pieces of polythene from insulation bags do this.

DJM · Posted: Mon Mar 03, 2003 11:55 am Post subject:

OK, problem recurred so I have had a much closer look. Diary of events below

Monday : low pressure on cold, so attach mains via hose and seems to clear. Smile

Tuesday to Friday : Monitor both hot and cold water pressure - both remain OK Smile

Saturday Morning : Left hot and cold water running whilst cleaning bathroom and having shower, and after to monitor water level in water tank. No significant drop in tank water level observed, pressure OK. Silent fill providing full flow mains at constant pressure. Smile

Saturday Evening : Water pressure OK whilst family having showers. Smile

Late Saturday Night, ok early Sunday Morning : Basin cold tap pressure seems lower, but probably not in fit state to make rational judgement. Sad

Sunday Morning : Pressure on Cold very low and shower almost unusable. Sad

Between Sat evening and Late sat night no water would have been drawn as we were all out Confused

Rest of Sunday : Drained down system - which took an age and reinforces the idea that any air entering system is not via tank emptying. Noted that the hot pipe is a few mm higher than cold - again suggesting air not getting in that way or it would be hot not cold that had air lock.
Cleaned out tank completely. There was some scale an other debris in the bottom of the tank, but not so much or of a size that seemed likely to block pipes.

Attached hose to taps and pushed mains though up to empty tank. Examined tank for debris. A few small bits, but again nothing spectacular. Didn't seem likely to cause blockage. Did same to hot just for the hell of it. similar amount of debris to cold. Certainly not much.

Re-emptied and cleared tank of debris so the tank was completely clean. Re-filled tank and cleared airlocks to taps etc. Acceptable flow to both hot and cold. But noticed that cold whilst Ok was still not quite as strong as hot. Confused

As they are from same tank with same head of water any ideas why Question

Now I hope this clears problem, but I doubt it so anything else I can try Question

Sorry for long post, but I can't spend every weekend fitting hoses to taps and am beginning to despair.

Thanks