Gunge in expansion tank.

[Bogart]

Had a quick loook in the CH feed and expansion tank as have been meaning to flush out the sysytem and refresh the inhibitor. Put in fair bit of Fernox F3 few weeks ago and due to one thing or another it is still in there.Anyway on looking into the tank saw a sort of clear coloured gunge sitting around the tank edge at the surface of the water and also sitting around ball valve level with water surface. Any ideas as to what it could be? Thanks

 

[sammathias]

Did you partially drsin the system then add the f3, via the tank?

 

[Bogart]

Yes precisely that.

 

[king of pipes]

This often happens when the f3 has not all gone into your system some has stayed in your feed and expansion tank and created this gunky mess , isolate the inlet a bungey strap on the ballvalve and clip up wet vac the tank out and wipe out with blue roll , to introduce fresh inhibitor you will need to drain down more than you did the first time so it goes into the radiators and boiler . cheers kop

 

[Bogart]

Thought I had drained down quite a bit obviously not. First job to remedy after the festivities. Thanks

 

[Bogart]

Drained tank and here is a photo of what I was talking about. As you can see is an opaque white sludge that comes away in strings. I would love to know what it is and why it occured on a new tank weeks after installation.

 

[Bogart]

Just spoken to fernox who have told me it is a biological growth and to treat my system with AF10 they also said was not caused by the F3 being in so long but have been advised to flush through and remove the F3.

 

[Bogart]

Now I see that Sentinel do a product X700 which is about half the price of the Fernox one and covers the same amount of CH capacity so think will opt for that.