Removing corrosion/magnetite sludge: Sentinel X400 or x800?

[Ant1]

I need to clean my central heating system due to corrosion/magnetite sludge producing excessive hydrogen (did the test with the match which confirmed this was hydrogen).

What is the best product to get rid remove corrosion/magnetite sludge? Is Sentinel X400 more appropriate than X800? What is the difference between both products?

Thanks for your help,
Ant

 

[Agile]

X400 takes 4-6 weeks.

X800 takes 2-4 hours!

But neither remove sludge. Both are chellating agents which try to get loose particles into suspension.

If you want to actually dissolve the sludge you need citric which is sold for the purpose as Fernox DS40. The older type in the plastic tub is far better than the square cardboard box!

Tony Glazier

 

[Ant1]

Thanks Tony, exactly the answer I was looking for. Will buy from of those Fernox DS40, I was not aware of this make.

Regarding inhibitors, is there a big difference between the Fernox and Sentinel products?

I usually use Sentinel x100 but Fernox range seems very similar. Have you got any preferences yourself?

Cheers,
Ant

 

[Agile]

I prefer Sentinel as they seem easier to use but that may be because I largly stick to them so that I best understand their characteristics.

Before you decide to use citric acid be aware that unless its used very carefully it can expose weak sections of rads and cause them to leak!

Tony

 

[Ant1]

Thanks again Tony, all my radiators are quite recent (apart from one), had them upgraded around 3 years ago. Hopefully they should hold.

I already ordered Fernex DS40 with Fernex Superconcentrate Protector F1, thought I would change from Sentinel x100 for a try.

I bought the version of DS40 that comes in the plastic tub. Then I noticed on the Fernex web site (they are only selling the powder version) that DS40 cannot be used with single feed indirect cylinders, e.g. ‘Primatic’ or similar.

I have a gravity fed system, the cylinder is a coil type double feed indirect (Dublotank 100), does this mean I cannot use DS40 with my CH system? Thanks for confirming (if you know), I might be able to cancel my order.

Ant

 

[Ant1]

Actually I should be fine, did not know the difference between single and double feed cylinders (//www.diynot.com/forums/viewtopic.php?t=206316).

It would be great if anyone could confirm that DS40 is ok for double feed cylinders.

Cheers,
Ant

 

[Agile]

DS40 is fine for everything apart from Primatic cylinder or an aluminium heat exchanger in the boiler.

You are lucky to get the proper stuff in the tub!

Dont use it all at once!

I add it bit by bit and taste it to see the acid left. I stop when it has not used up all the acid. You need to circulate it at the minimum temperature or with the pump on and the boiler off.

Tony

 

[Ant1]

Thanks again for the valuable advise Tony, would never have thought it would have been safe to taste. I shall receive the DS40 tomorrow to be ready to do the work at the weekend.

 

[David937]

What boiler have you got out of interest? Hope it does not have an ali heat exchanger! And don't taste it please.

 

[Ant1]

Hi David,

My boiler is a Baxi Back Boiler 552, I think it is made of cast iron with no aluminum in it. Is my assumption correct?

Thanks,
Ant

 

[David937]

Hi David,

My boiler is a Baxi Back Boiler 552, I think it is made of cast iron with no aluminum in it. Is my assumption correct?

Thanks,
Ant

Yes.

 

[ChrisR]

would never have thought it would have been safe to taste

It's not. Tony is being silly! Apart from Malic Acid and colouring agents. they don't tell us what's in it.

Don't forget you have to neutralise after you've done the job.

If the rads are only 3 years old I doubt it's all that bad. Before you start with chemicals I'd use the mains to push out what you can. Connections are always an issue though, you have to work out where the water can go -( like throug hthe HW cylinder coil if you have a 3 port valve) that you don't want it to.

The 552 is cast iron all right. Watch for leaks at the unions where the pipes go in, after you're done. If you get a weep don't panic, you could use a leak sealer inthe water.

 

[Ant1]

Thanks David / Chris.

(like through the HW cylinder coil if you have a 3 port valve) that you don't want it to.

Are you are saying that if I have a 3 port valve, I should net let any of the DS40 go through the HW cylinder coil? But then how the product would circulate through the complete system?

 

[Agile]

The original DS40 is mostly citric acid with a little malic acid.

Lemon juice in kitchen terms.

I am not recommending that anyone drinks it but I do taste a tiny amount on my finger to estimate how much acid is left.

Still alive!

Tony