Problems adding Fernox F5

dizzyscot

Hi all,

I'm just wondering if anyone who has added Fernox to their CH system can advise where I am going wrong. I have sludge in my system resulting in the boiler kettling and some of the radiator not heating up properly. I want to add some F5 to see if it helps. I tried to add it via the filling loop as it seemed a very straightforward method, but unfortunately it hasn't worked. When the can is attached to the filling valve and the nozzle is pressed, the Fernox is not being discharged from the can. Any ideas?

Many thanks in advance.

Lorian

What do you have, cartridge or bottle?

dizzyscot

Thank you for replying

Its Fernox Express F5, which is a pressurised canister with a nozzle that attaches to the filling loop.

Lorian

valve needs to be open after the can is connected....

https://www.youtube.com/watch?v=pi7hd7rM8X0

I presume you are going to drain, flush, re-fill and re-dose at some point?

Mr.Generous

If you have a towel warmer type radiator in the bathroom just buy normal bottles - they are very easy to top up. Before you try and add pressured stuff release a bit of pressure from a rad via a drain !!!! or bleed valve to make it easier. Most combi's should be between 1 - 1 1/2 bar from cold.

Ha it blanks out drain (word for a rooster - 4 letters, ends in ock)

dizzyscot

That was the exact video I used to show me how to do it! It makes it look so easy. I connected the nozzle to the filling loop, opened the value, and pulled the wee lever but the contents weren't discharged. It's as if the pressure isn't strong enough to get it into the system.

Mr.Generous

see my post, drain off some pressure first.

dizzyscot

I think the boiler is sitting at 2 bar so I will reduce the pressure and try again.

Yes Lorian, I'm going to leave it in for up to a week, drain, flush well and refill, then add F1.

Thank you both so much for your help. Hopefully I'll have more success tomorrow.

Cheers :beer:

dizzyscot

Morning everyone.

So I drained the system a bit so the pressure in the boiler reduced to 1 bar when cold. But it's still not working! Should I reduce the pressure further?

Le_Kirk

Mr.Generous wrote: »

Ha it blanks out drain (word for a rooster - 4 letters, ends in ock)

If you type draincock or stopcock it is fine and most people understand what you mean.

Rubidium

dizzyscot wrote: »

Morning everyone.

So I drained the system a bit so the pressure in the boiler reduced to 1 bar when cold. But it's still not working! Should I reduce the pressure further?

Are you disconnecting the wrong end of the filling loop and trying to expel the contents of the can into the mains water pipe?