No Cold Water ( well not after 5 seconds ) - Please help...

27 Aug 2004
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United Kingdom
HI All

Heres the brief sequence of events......

1) Power shower pump stops working.
2) Isolate shower supply using inline valves.
3) Inline vales not completley stopping water so turn of house water supply.
4) Drain tank using upstairs tap
5) Fit new shower
6) Turn on Manis water and shower valves.

Outcome - No water pressure upstairs ! The three valves i have touched are all open, the cold water tank is full. When you first turn the tap on it seems a little slow but it then pretty much stops.

Ive tried leaving the tap running thinking it might be an air lock, ive plungered the tank on teh roof on the outlet providing water and even flushed the loo in a vauge attempt to get it to work

PLEASE HELP - I turn the upstairs taps on and get a small trickle which then pretty much dries up. The water downstairs is fine and the tank refils ok.

Any ideas ?



PS - The hot water and water down stairs is fine !
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Sounds like you may have got some gunk in the pipes. My mother once suffered from a severe drop of pressure in her upstairs plumbing. Upon investigation I found the remains of a pigeon corpse (that must have been months old), in the header tank. How the heck it got in, I havn't a clue.

I emptied the tank, (by syphoning it out with a garden hose led through the soffit). cleared all of the solids manually. Then connected a garden hose to kitchen sink tap, led it upstairs to the bathroom sink cold tap. Gave it a bit of a blast, then did the same to the Bath cold tap.

Due to the nature of the contaminant, I then cleaned the inside of the tank, thoroughly with bleach, poured about another gallon of bleach into the tank, and refilled it. I then opened up all outlets and allowed it to flush through, untill the smell of bleach had dissapeared. I don't suppose this was a recomended procedure but I needed some psychological reasurrance to stop my stomach churning.
Cheers for your reply. No dead pigeons here though.

First thoughts of an air lock were correct but simply turning the taps on didnt work.

Used the garden hose ( mains pressure ) connected to the upstairs tap and flushed the airlock back ot the tank.

All sorted now -

Hopefully the post will help someone in the future anyway.


You had a classic air lock. Easiest method withthe hot is often at the washing machine. You have the mains and hot there, with taps and hose to connect them together.

For the upstairs cold, an aquavac (or a quick suck with a dry vac with a rag in the way) will often work in a couple of seconds.
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I did something similar: turned off supply to cold cistern in loft, forgot to turn it back on again. Had shower, after 10 minutes the pump made funny noises and cut out. I used the "mains water to push the wrong way up the pipe" trick, worked a treat.

Tex, I used to work in a bar and one of my jobs was cleaning the lines. I got the solution on my hand one day and felt a familiar "soapy" texture to it. Read the label, sure enough it was Sodium Hydroxide (NaOH).

NaOH can be used as a steriliser, and as it can be used in beerlines, must be approved for food use. Not going to turn you blind if the pipes aren't flushed entirely, and has very little flavour/odour.

So I reckon that anyone else who needs to do this might find it easier if they use NaOH to kill the bugs.

Hydrogen peroxide might work too, but the problem with this is it dissociates into water and oxygen. Manganese (found in blood) makes this happen rather quickly (catalyst)... so if you have dead pigeon guts in your pipe, peroxide might cause new airlocks!
Jeez I hope NOBODY puts any chemicals in their water systems without knowing exactly what they are doing. Sodium Hydroxide is extremely dangerous stuff which can cause severe burns and swelling. It could easily cause death if in someone's throat.

Chlorine is used to sterilise water pipes, but you have to be careful to get it right and its not a DIY operation.

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