Brown "algae" in hot water All aspects of plumbing questions and answers, help, tips and information

[fungobungo]

I have what looks like brown algae coming out of my hot water taps. I assume it's also in the boiler. How do I deal with this?

I assume that I need to drain the boiler (I may need to get a tradesman to to this) but I'm concerned that the algae will just come back after a while.

Grateful for any help!

[nitro23456]

Do you have an indirect hot water system - ie hot water cylinder with cold water tank in loft?

if so are you sure the cylinder coil hasnt broken and that central heating wayer isnt getting into your hot water? - could be gunk from this.

[fungobungo]

Yes, have a cold water tank in loft and a hot water cylinder. Don't have radiators however - have a warm air heating system in the house (yes - weird I Know!). Not sure how the air is heated - directly or via hot water. Not sure if this makes a difference re cylinder coil.

Assume a new water tank would fix this!

[chris_on_tour2002]

the gunk is almost certainly in the boiler/heating side (it will still feed the heat exchange coil in the hot water cylinder even though it is not feeding radiators). most likely is that the coil in the cylinder has ruptured.

it is possible that the gunk is getting into the cylinder from the CWSC in the loft if that is heavily sedimented, might be worth draining and cleaning it out.

if the coil has ruptured then its a new cylinder. you will have to clean and flush the whole system anyway so replacing the cylinder should solve the problem wherever the algae is coming from.

[nitro23456]

it is also worth noting that if this disappears (given how long ago this was posted), the problem is in fact still there and that the water has run clear as fresh water is drawn in to replace the treated water that you have lost.