TRICKY PLUMBING PROBLEM

zxcvbnm12

a lady rang me today to say that her tank was overflowing in the attic and that she could hear a gurgling noise at the kitchen sink.anyway i called as quick as i could and when i got there she had drained the tank to its normal level through the bath taps and she said the ballcock wasnt the problem.i opened the press under the kitchen sink and i could hear water flowing through the pipe when everything in the house was off/full.i find it strange that the tank is overflowing and the water noise at the kitchen sink is also rattling my brain.any ideas?

Billy Bunting

if the tank is overflowing then the mains will keep filling it, thus the noise.

zxcvbnm12

no the ballcock stops perfectly so thats not the problem

Davy

zxcvbnm12 wrote: »

no the ballcock stops perfectly so thats not the problem

Why did she think her tank was overflowing then?

zxcvbnm12

because the water was flowing out the overflow.sorry if i havent described it great.

Solnskaya

Are there any thermostatic or mixer taps where the flow may be crossing from the cold to the hot pipe through the tap body? Or, is there a cylinder in the hot press? Somewhere within the system the cold feed must be crossed up with a hot feed and is backfilling the attic tank through the hot pipe. Have a look into the tank with a flash light and you should see the disturbance of water being forced in through what should be outflow pipe, or press your finger over the pipe flange to feel for reverse pressure. This could also possibly occur if the internals of the cylinder had failed and were allowing a backflow but it's more likely at a tap. (Unless she has had other work done recently and some muppet got his connections mixed up.)

Regardless, a mains fed pipe must be feeding a tank fed pipe, if you get my drift. Turn off the main house feed stopcock for confirmation of diagnosis-mains off, tank should stop filling, and I don't mean via the ballcock.

Davy

The noise at the sink, is it water running in the rising mains, or just the sound of waste, eg washing machine/dishwasher happened to be on and she assumed it was related to the overflow

Solnskaya

On a more basic level, have you confirmed all the facts? Is the ballcock really working correctly? Is there a central heating tank above the main water tank, if so, is its ballcock working? Have any pipes been altered/renewed recently?

Solnskaya

Davy wrote: »

If it was, the ball valve is faulty in some form.


The noise at the sink, is it water running in the rising mains, or just the sound of waste, eg washing machine/dishwasher happened to be on and she assumed it was related to the overflow

Possibly, but not definite. a mains pipe crossing to a tank fed pipe pipe would also create this. Can and does happen.

zxcvbnm12

ya there is a mixer tap at the kitchen sink.this tap is only about 6 months old.all i could think of was that the mains was too powerful at the tap and it broke some seal on the tap and was pushing the hot back through the cylinder and re filling the tank from the 350.but then i was thinkin wouldnt it drive the water up the vent pipe as it would be an easier path?

zxcvbnm12

to answer the questions.it is definately the mains flowing under the sink that i can hear and not waste pipe.the ballcock is definately stopping and the heating tank is in a diff part of the attic and that is fine

JohnnieK

Is there a toilet overflowing? Could be an external overflow pipe somewhere that can't be seen

zxcvbnm12

no i made sure everything that needed water was full and had stopped filling,the "water flowing noise" was still going at the kitchen sink.i told em not touse any water for a few hours and she rang about 2 hours later saying that the overflow was pissing water again

JohnnieK

Then it has to be the ballcock. Tell her not to run any taps and call you when it happens again. Is the overflow off the main tank or F&E tank?

zxcvbnm12

the o flow that leaks is the one on the big tank.when everythin was full i spent about 10 mins in th attic and there wasnt a drip from the ballcock.the noise was still at the kitchen sink all this time so i cant see why it cud be the ball cock

JohnnieK

Something else must be teed into that over flow pipe. Or maybe its intermittent fault with the ballcock. It might be the case that you will have to stay up at the tank for a good bit longer to observe best bring your radio.

zxcvbnm12

i tracked the overflow and its definately going out on its own.the only thing that puzzles me is that if it was the ballcock,shoulndnt the water noise at the sink stop when the ballcock is stopped.thanks for ur help anyway johnnie.im gonna sleep on it

JohnnieK

Thats a good idea. Why dont you stick a valve on the mains at the tank and turn it off for a while and see if the noise stops. Good night..

DublinDilbert

Is there any chance that the washing machine is taking in mains cold & hot from the tank? Many machines in old houses are plumbed this way. The water could be crossing over inside the washing machine. The noise you hear at the kitchen sink might be the water flowing via the washing machine.

slavetothegrind

washing machines have individual valves and paths for hot and cold it wouldn't be possible to force cold mains back through the tank fed hot inlet.

can you fit an isolating valve on the kitchen mixer tap to close off the mains feed to it?

Stove Fan

As has been said I would disconnect/isolate the water connections to the mixer tap and see if it continues. If not I would suspect the heating coil in the cylinder for a pinhole leak. What would happen is water from the heating header tank filling the main storage tank and overflowing. Particually if the heating tank is higher.

James:)

sullzz

Is there a pressure reducing valve on the heating , I wonder would the coil be leaking and sending water back into the attic tank , try turning off the cold feed to the cylinder and check if it comes out the expansion pipe . Or if there is a header tank check to see if that's constantly filling

zxcvbnm12

ya the heating tank is higher than the big tank but i looked into that and there was no movement or disturbance in the tank.i will be calling there tomoro and i will blank the hot and mains at the mixer tap and if the problem still arises at least i will know the mixer tap is not the problem.

JohnnieK

How did you get on with that haunted overflow pipe?

zxcvbnm12

sorry about the delayed reply.well i called to the house and put on 2 penny valves on the hot and cold on the mixer tap at the kitchen sink.the minute i turned off the penny valves the noise stopped.i turned them back on and went up to the attic.i shined a light into the tank and cud see pressure coming out of the 350.so after all that it was the tap that was the problem.thanks for all the help anyway

JohnnieK

I have learned something new myself here today

Solnskaya

Solnskaya wrote: »

Are there any thermostatic or mixer taps where the flow may be crossing from the cold to the hot pipe through the tap body? Or, is there a cylinder in the hot press? Somewhere within the system the cold feed must be crossed up

Blows on fingers and sits back smugly:D

zxcvbnm12

ya,u were bang on to be fair solnskaya.the thing that i thought was a bit wierd was why it wudnt drive it up the expansion instead of the cold feed because it wud have an easier path.ah well tis sorted now,thanks again to ye all

DanWall

Has it got the one lever type faucets on the sink. There is a limited pressure differential that these can take between the cold mains pressure and hot water pressure from the header tank. It could be flowing from the tap back up the hot water supply to the header tank