Fernox DS40 through HW cylinder coil safe?

[Ant1]

I am about to use some Fernox DS40 to get rid of corrosion/magnetite sludge in my CH system (due to excessive hydrogen being produced).

I have a gravity fed system, the boiler is a Baxi Bermuda Back Boiler 552 an the cylinder is a coil type double feed indirect (Dublotank 100). With this kind of system, selecting either hot water only or central heating will always force the hot water flow to go through the coil in the HW cylinder.

Is this safe to let Fernox DS40 go through the coil in the HW cylinder?

If not, my only solution would be to change the jumper at the back of the timer from Gravity to Pumped system. This should allow the 3 way valve to allow the hot water flow to only go through the radiators (and not the coil) when selecting the CH setting. But would this be safe? And how can I make sure the hot water does not circulate through the coil?

Any help would be appreciated.

Thanks,
Ant

 

[OLLIE20]

You are ok to put chemical in aslong as its not a primatic cylinder and you are sure its an indirect coil, if you have a 3 way valve it wont be primatic as will be a fully pumped system, which isnt compatable with a primatic

Putting it in will not cure your sludge problem, it may help with the hydrogen for a while

 

[Agile]

Put in at the right concentration its got a good chance of dissolving all the sludge.

Why do you think it will not?

 

[OLLIE20]

If a system is Full of sludge how will putting a chemical in get rid of all the sludge?

Powerflushing after using a desludger and then treating afterward will not remove 100% of magnatite, so how will putting it over everything and just leaving it there do much?

Ive just realised its a descailer not a inhibator, but still putting it in and leaving will do next to nothing, put it in adraining will do a little, but if the system in badly sludged it needs powerflushing properly

 

[ChrisR]

As long as there's circulation it'll dissolve almost all the oxides.
As you didn't know what it was you might be surprised how active it is.

 

[OLLIE20]

As long as there's circulation it'll dissolve almost all the oxides.
As you didn't know what it was you might be surprised how active it is.

Fair enough, i will have to stand corrected as i have never used it, find it hard to believe its that good, as why wouldnt ppl just use this instead of flushing, much easier and cheaper and according to you with the same results

 

[Agile]

If you have never used DS40 then you will not realise that its an acid ( citric/malic ) which DISSOLVES metal oxides.

It is highly effective!

But its just that effectiveness that limits its usage. As it dissolves oxides its very likely to cause leaks in rads and will virtually always cause some rad valves to leak.

As a rule of thumb most people would only use it on systems no more than five years old!

I use it to desludge blocked boilers but would rarely use it on the rest of a system.

Tony

 

[Ant1]

Thanks all for the advice, it seems safe to use Fernox DS40 in the HW cylinder coil, so I'll give it a go.

Cheers,
Ant