Brown sludge obstucting heating circuit.

[Bydandforaye]

I have a conventional open vented heating system with a Potterton CF boiler feeding both central heating and domestic hot water.

My problem is that the Myson air separator clogs up with brown paste every two years approximately. The symptoms are extended running of the pump and increased heating times.

This problem has been around for the last 15 years since I bought the house but is something I have come to live with.

To improve hot water recovery times (four ladies in the house!) I changed the two port electric valves for a Grundfoss Plumplan unit which has two pump heads in one body and electric valves become redundant. An excellent piece of kit when working well.

Back to the problem – the brown paste builds up in the air separator and flow pipe work restricting the bore of the pipe and will eventually totally obstruct the pipe if not cleared away.

To enable a quick clean out, the pipe work has been changed with compression joints allowing easy disassembly of the air separator for cleaning.

Cleaning is achieved with a tooth brush and cold running water.

Once cleaned out and reassembled all is well for at least 18 months.

I know how to deal with this problem but what I would like to find out is why does it occur?

Do I still need the air separator?

Help please.

Many thanks

 

[Agile]

You seem to have gone to a lot of trouble to make it easy to clean without dealing with the underlying cause!

I would guess that its sometimes pumping over. You should check that ( see FAQ ) and pump a plastic bag over the vent to see if it does it when you are not looking.

Others will say fit a magnaclean but I would say correct the underlying problem and add inhibitor and you should get no further problem.

The brown sludge is iron oxide. The iron has come from the inside of the rads and one day some will start leaking.

Tony

 

[Bambergaspipe]

Do I still need the air separator?

No, installed in older systems about a hundred years ago, take it out it`s useless. That`s why we don`t use them anymore nor fit conventional systems unless unavoidable, the sludge will merely sit in your small tank feeding your hot water system, which will barely be noticeable. It took you 2 yrs to notice it in the size of a small saucer. You could have a ball with a small tank.

There maybe a chance that you may have to re- configurate your old pipework though, because years ago when they installed your system they didn`t have a clue and it was airlocking it`s ti*ts off so they introduced the `air seperator` or `airjec`. this can be solved quite easily by a competent plumber.

 

[Agile]

The air seperators are usually retrofitted to existing systems which have been wrongly configured as an attempt to reduce problems.

I have never fitted one but I have converted several problems to single vent and feed pipe to get over problems. So far all those i have done have cured the problem.

Tony

 

[Bambergaspipe]

The air seperators are usually retrofitted to existing systems which have been wrongly configured as an attempt to reduve problems.

Is that a word? if it is it`s very interesting, what does it mean?

 

[Bydandforaye]

My thanks to all those who responded so quickly.

I will check if the system is over pumping and start planning on removing the air separator in the summer.

 

[bengasman]

In other words, your whole system needs cleaning properly, servicing properly and treating with inhibitor.
I am amazed your boiler has not rotted through yet, but expect this to happen any moment now