Fernox DS3 vs DS40

[JackFrobisher]

I want to descale my heat exchanger. I've read the last 12 months' threads about the ways to do it and now I want some Fernox. I'm faced with two types, both of which it appears will do it: DS3 at about £10 and DS40 at about £20.

Does anyone know the difference and will I get any benefit from using DS40 at twice the price? The Fernox web site does not refer to DS40.

BTW, the heat exchanger is currently dismantled and sitting in a bucket awaiting its bath...

 

[VicS]

[ QUOTE ]
The Fernox web site does not refer to DS40.

[/ QUOTE ] Oh yes it does Its is in the "cleaners" section while DS 3 is listed as a limescale remover. DS 40 is based on organic acids DS3 on sulphamic acid

 

[JackFrobisher]

Thanks. /forums/images/graemlins/smile.gif

I thought it was odd that it wasn't on the list of Limescale Remedies.

So ... would I be right in thinking that (effectively) there's no difference?

 

[david_bagshaw]

A cheaper answer and just as effective imho is to use brick cleaner from builders merchants, obviously with heatexchanger core removed and in a bucket.

 

[savageseadog]

The Sulphamic acid DS3 version will be very gentle on the metalwork, If you've got anything other than cast iron or steel in your cooling system don't use anything stronger.

 

[VicS]

[ QUOTE ]
A cheaper answer and just as effective imho is to use brick cleaner from builders merchants

[/ QUOTE ] Well yes but brick cleaner is based on hyrochloric acid, which is a strong acid, and will remove limescale more quickly than the weak organic acids in DS 40. Unfortunately it will also attack the metal parts of the heat exchanger more quickly as well. DS3 is based on sulphamic acid which is stronger than the organic acids in DS40. That is why it will remove limescale more quickly than DS 40 might but but the organic acids will be more effective in removing iron oxde based deposits in a central heating system.

The Fernox products are inhibited to minimise attack on the metal as hydrochoric acid would be when used industrially for acid cleaning. You will find guidance with Fernox DS3 or DS40 on the concentrations to use but you will not find any guidance on the container of brick cleaner as to what concentration is suitable for descaling heat exchangers!

If you want a quick result or if the cost of some DS3 is going to make a significant dent in your boating budget and you are prepared to risk some attack on the heat exchanger use brick cleaner diluted about 1 part in 10 parts water. Keep an eye on it and stop once all the limescale is removed. Neutralise the acid with some washing soda.

 

[PembrokeshirePromise]

It was the DS3 (less strong) that I have used in the past

 

[VicS]

[ QUOTE ]
DS3 (less strong)

[/ QUOTE ] DS3 is based on sulphamic acid which is stronger than the organic acids in DS40.