Smelly / Slimey water in central heating header tank

[Rule Zero]

Hello.

I had a major boiler repair at Xmas and the engineers had to drain and re-fill the central heating system during the repair, they used Fernox when they re-filled it.

About a month later, the smell from the central heating header tank had become overpoweringly awful, like rotten eggs. The tank is in the top of an airing cupboard in a bedroom, as there is no loft.

So, I drained the system down completely, let clean water flush it through for a bit, then let it re-fill with clean water and added a bottle of Sentinel X100 and X200.

Now, nearly a month later and the smell is returning, the water in the tank seems quite slimey also. All rather unpleasant.

Any ideas why this is happening and what I can do to fix it? It is going to get very expensive and inconvenient to have to re-fill all the water and Sentinel each month.

Many thanks

Lisa

 

[seco services]

can you see into the tank ? no foreign bodies in the bottom.

 

[Rule Zero]

can you see into the tank ? no foreign bodies in the bottom.

Hi, thanks for replying.

Yes, I can get access to see in to the tank using some steps and a torch.

When I emptied it I did have a good look, there is some scale and sludge, but nothing else that could be called 'rotting matter'.

How about if I empty the tank, and give it a good clean with bleach. Would there be a problem if some of the bleach got into the central heating system?

lisa

 

[Onetap]

About a month later, the smell from the central heating header tank had become overpoweringly awful, like rotten eggs. The tank is in the top of an airing cupboard in a bedroom, as there is no loft.


Now, nearly a month later and the smell is returning, the water in the tank seems quite slimey also. All rather unpleasant.

http://www.fernox.com/problem+solving/how+to+sheets/avoiding+bacterial+contamination


It is difficult to stop bacteria breeding in the F&E cistern since it is stagnant and the water should never get hot enough to kill all the bacteria. Sterilize it as the Fernox recommendations. You'll probably find similar advice on other chemical treatment sites. I'd plan on turning it into a sealed system in the long term.