Mains Pressure Hot water System - Brown Sludge

[Michael Groves]

I got a Mains Pressure Hot water System, it's about 3 years old. The shower filters get blocked yearly, and if it gets drained for maintenance, when you purge the system, you get loads of brown sludge.
This is on the hot water side only.

How can I prevent this brown sludge build-up, and how can you clean it?

 

[steadyon]

What type of hot water system, combi boiler, unvented cylinder or thermal store?

 

[Michael Groves]

It's a system Boiler with an unvented cylinder. (UniCyl). All the plumbing was renewed during the installation.

 

[Scott_D]

Have you contacted your water supplier?
Might be worth having the cylinder drained, the immersion removed and the bottom checked

 

[Michael Groves]

Have you contacted your water supplier?
Might be worth having the cylinder drained, the immersion removed and the bottom checked

I've not contacted water company, cold water is fine, I'm guessing it's something to do with being unvented?

 

[ShaunCorbs]

That’s not normal do you have any steel pipework?

 

[Michael Groves]

That’s not normal do you have any steel pipework?

No, mixture of copper and Hep2o

 

[Scott_D]

Any pictures of your setup?

 

[Chuck]

Is it slimey or gritty?

If the former, it may be some sort of 'bio-film' growth. This is a potentially serious health hazzard and needs the system draining, disinfecting and checking for root cause, such as dead-legs in the pipework or incorrect storage temperature.

If the latter, I'd expect there to be a similar accumulation in and cold water filters and toilet cisterns.

If in doubt, get a sample analysed by a lab that offers water quality tests. Expect to pay £50-£100 for a one-off test but it should give a definitive result. Call them and ask their advice about what type of test you need before placing an order.

 

[Michael Groves]

It's slimy, no dead legs, everything brand new. We have secondary return pump, runs 24 hours.