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Water/plumbing question

(20 Posts)
purplepinny Fri 30-Sep-16 19:30:39

I have had this issue intermittently for the past 2 months or so. When I run the bath, the water sometimes has tiny black 'bits' in it and tonight a large black 'bit' came out of the tap. I scooped them out then turned the tap back on full and the photos show what came out. Does anyone have any idea what this is? The water from the sink taps next to the bath does not have this issue.
How do I fix this?

TheBitterBoy Fri 30-Sep-16 19:34:20

Could be a rubber tap washer breaking down, or it could be a biofilm. How often do you give your bath taps a scrub up inside? Do you get black or pink mildew around the taps especially in the winter? Bathrooms are lovely damp warm homes for mildew.

purplepinny Fri 30-Sep-16 19:44:59

Thanks! The answer is I've never scrubbed the inside of the tap. No mildew around the tap at all. There's no shower there and the bath is only used once or twice a week. It doesn't really get steamy. So, I should remove the tap and see what's inside?

TheBitterBoy Fri 30-Sep-16 20:02:10

Oh I'm not a plumber I work in Water Quality for a utility company. We get this kind of complaint quite a bit and those I listed are the two most usual causes. Do you have a hot water tank? Or a cold one in the loft? Is it just when you run the hot tap or the cold? Might be worth investigating which tap (or pipe if it's a mixer) is the source of the problem before you start dismantling anything.

purplepinny Fri 30-Sep-16 20:30:18

We have a combi boiler with hot water tank on ground floor. Bathroom is second floor. Tap is a mixer and the issue seems to be when hot water is pulled.

PigletJohn Fri 30-Sep-16 21:51:37

show us a photo of the bath tap, including one looking up the spout. How old do you suppose it is?

Are the bits hard and gritty, or soft and rubbery?

Does a magnet attract them?

PigletJohn Fri 30-Sep-16 22:02:15

have you got a spanner?

the links in here show how the grille or aerator in the spout can be removed. Any fragments tend to collect behind it.

Subject to tap age, I am also thinking of fragments of a rubber washer breaking up, but you seem to have got more than I would have expected. It might possibly be the diverter valve in your boiler, though that might mean your radiators warmed up when you ran a hot tap. So photos of the tap, and up the spout, may give clues.

If you have a combi and no water tanks, it would be strange to have black mould.

PigletJohn Fri 30-Sep-16 22:03:52


you said hot water tank on ground floor.

So it is not a combi,

What colour is the hot water cylinder?

Can you photograph that as well please (especially showing the top quarter)

PigletJohn Fri 30-Sep-16 22:05:37

(this might be quite worrying so please reply tonight if you can.)

Until sorted, I recommend that you brush your teeth at the kitchen cold tap and don't drink from any other tap.

purplepinny Fri 30-Sep-16 23:02:56

Hi piglet john. Oh dear. Quite worrying.. Hot water cylinder is green. House and boiler, taps are all 10 years old. Black bits are soft and leave black marks like a black pencil would. Very difficult to remove stain.

purplepinny Fri 30-Sep-16 23:04:16

More photos

purplepinny Fri 30-Sep-16 23:05:39

Trying to get good boiler pic..

purplepinny Fri 30-Sep-16 23:16:58

I just ran the bath taps again and it is fine. It seems to happen if it hasn't been run for a while. Don't know if the grey stuff was magnetic as I ran it away. Bath is metal so it does look like metal filings around a magnet?! Do you think my boiler is corroding?!

PigletJohn Fri 30-Sep-16 23:17:27


You have a green cylinder, which must be fed from a cold water tank higher in the house, most likely in the loft (unless you have a pump, which would be noisy)

Looking at the amount of black material, it seems to me to be too much, and the wrong texture, for a rubber tapwasher.

Unless it is attracted to a magnet, my best guess is that it is detritus from the loft tank, probably from something that has fallen in.

If you, or somebody braver, can get up there with a torch, a bucket, and a kitchen sieve, you can probably get it out.

If it is something undesirable, get somebody to turn on the COLD bathtap while you watch the loft tank. If the tap draws water from the tank, you will see the ballcock open and start to squirt water into it.

Come back and tell me if it does and I will advise further. Don't run the taps again until advised. Use the kitchen cold tap, which comes straight off the main and will be clean.

If you are lucky there might not be anything undesirable in there.

Keep the hot water cylinder hot (turn up the thermostat if you know how) because the heat pasteurises it and kills many bacteria.

purplepinny Fri 30-Sep-16 23:29:15

We're 100% sure we have no cold water tank. When we go on holiday we shut off the mains water on the ground floor and that shuts off all water immediately - no water from taps and toilets don't refill..

PigletJohn Fri 30-Sep-16 23:33:08

A green hot cylinder is vented, so it has to be filled from a tank. It is not built to stand mains pressure.

It might be that all the cold taps and the WC are fed straight from the main, this is done in some parts of the country.

purplepinny Fri 30-Sep-16 23:40:15

OK. We're in Scotland if that makes makes a difference. I'll get upto loft in the morning and check but sure there isn't one there. Thanks so much for your help. Really hoping there's no dead birds up there...

purplepinny Sat 01-Oct-16 14:01:33

I've checked and we don't have a cold water tank. Our boiler is an Ideal istor and after googling found that it is an unusual type and takes mains water in. Probably something in the tap or pipe to taps then?

PigletJohn Sat 01-Oct-16 15:05:34


it sounds like some kind of thermal store. I can't see how the black material is getting in, I'm afraid. There seems to be some kind of blending valve, but I'm puzzled by the large amount of material.

You may do better with someone familiar with this model. Sorry. It mighty help to keep the black stuff in a jar to show them.

user1475904681 Sat 08-Oct-16 11:08:44

Message deleted by MNHQ. Here's a link to our Talk Guidelines.

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