Black oily bits coming from hot tap

[CharlieMcT]

Hello there.

I wonder whether anyone could suggest what may be the issue with the hot water in my bathroom. I have asked four different plumbers who have come to the house to do work and none of them had a clue.

Basically, when I turn on the hot tap on the bath, black bits come out in the water. They are oily - i.e. if you take one between your thumb and finger and rub it, you get a black smeary mess. They stick to the side of the bath and can only be removed by scrubbing with a scourer and Cif. The issue is so bad I now can't run a bath and in order to bath my daughter I have to fill the bath half full with the electric shower (expensive!!).

We moved into the house last August, and the issue has got worse since then. The entire bathroom was refitted in October, so I don't think it's a pipe or connector in the bathroom.

Recently I was trying to fill the bath by filling buckets of water from the hot tap on the sink. But then, after the 8th bucket, the basin tap spat out the black stuff too. Only time it's done it.

We have a combi boiler, and no other tap in the house is affected.

Any ideas much appreciated! I thought about calling a boiler engineer, thinking maybe the issue is the boiler, but then I'm unsure why it would be only the bathroom hot tap(s) affected, not the en suite, downstairs loo, kitchen etc.

 

[Deleted member 120897]

I personally don’t think it’s the boiler. Sounds like a breakdown of the rubber tap washer inside the tap innards.

 

[CharlieMcT]

I personally don’t think it’s the boiler. Sounds like a breakdown of the rubber tap washer inside the tap innards.

Thanks for commenting. The taps on the bath and the basin are new, fitted recently. The problem existed before the bathroom refit and has just got worst since.

 

[Last Plumber]

I can't understand why four Plumbers can't sort it out or at least diagnose the cause.

Which Combi boiler (make and model)?
Where does the water supply come from, is it mains? just to rule out well water or tank fed and boosted supplies.

If it is a Combi off the mains, I would say chances are it is something in your internal plumbing which is degrading.

When was the Combi installed? or was that in before you?

 

[Deleted member 120897]

Would get any flexi hoses checked out to rule those out too.

 

[plumbingservices]

It's sad that the plumbers didn't identify the issue correctly. Sometimes the black substance comes from some corrosion in the main water supply, or due to excessive minerals present in the water. I think without any proper diagnosis it's very hard to tell the exact reason. Go for a professional plumber and ask them to diagnose it properly.

 

[CharlieMcT]

Thanks for the replies.

It's a combi boiler, a Worcester-Bosch Greenstar 305i MkIII, installed in 2009. Probably not been maintained well, I think.

The flexi hose makes sense. I'm wondering whether the plumber who refitted the bathroom reused the existing flexi hose rather than replacing it as I'd asked. I'll get someone round to check on that under the bath - then maybe it's a simple fix.