Hi all,

I am just finishing off the installation of a new C/H system. The tank
and boiler instructions recommend Fernox-brand inhibitor, but there
are lots of other inhibitors on the market. Will I see a noticeable
difference between a cheaper inhibitor like Triple-X (http://
www.toolstation.com/messages.html?code=94504), and a more expensive
inhibitor like Fernox F1 or Sentinel X100? This is for a 300l heat-
bank system, so the difference in price between cheap and expensive
adds up. If the expensive stuff simply comes in a better class of
bottle, but contains a virtually identical liquid, then I may as well
get the cheap stuff!

thanks,

dan.

wrote:
Hi all,

I am just finishing off the installation of a new C/H system. The tank
and boiler instructions recommend Fernox-brand inhibitor, but there
are lots of other inhibitors on the market. Will I see a noticeable
difference between a cheaper inhibitor like Triple-X (http://
www.toolstation.com/messages.html?code=94504), and a more expensive
inhibitor like Fernox F1 or Sentinel X100? This is for a 300l heat-
bank system, so the difference in price between cheap and expensive
adds up. If the expensive stuff simply comes in a better class of
bottle, but contains a virtually identical liquid, then I may as well
get the cheap stuff!

thanks,

dan.

I don't think any of them contain anything much other than a mild acid,
like boric.

wrote:
Hi all,

I am just finishing off the installation of a new C/H system. The tank
and boiler instructions recommend Fernox-brand inhibitor, but there
are lots of other inhibitors on the market. Will I see a noticeable
difference between a cheaper inhibitor like Triple-X (http://
www.toolstation.com/messages.html?code=94504), and a more expensive
inhibitor like Fernox F1 or Sentinel X100? This is for a 300l heat-
bank system, so the difference in price between cheap and expensive
adds up. If the expensive stuff simply comes in a better class of
bottle, but contains a virtually identical liquid, then I may as well
get the cheap stuff!

thanks,

dan.

Suggest a look he

http://wiki.diyfaq.org.uk/index.php?title=Corrosion_Inhibitor

Can't remember what I used, but it seems to be doing the job. It
*wasn't* Fernox!

--
Rod

Hypothyroidism is a seriously debilitating condition with an insidious
onset.
Although common it frequently goes undiagnosed.
www.thyromind.info www.thyroiduk.org www.altsupportthyroid.org

stuart noble wrote:

I don't think any of them contain anything much other than a mild acid,
like boric.

I'm no chemist but I think that's utter nonsense. For a start the pH of
Fernox MB-1 (probably still the most common inhibitor?) is given as
8.3 - 8.8 for the concentrate [1], so it's hardly acidic. Fernox say:

"The majority of domestic central heating inhibitors are essentially
anodic passivators. This type of inhibitor reacts with the metal (anode)
being corroded to form a very thin film that prevents any further metal
being lost. The film is only maintained by the continued presence of
inhibitor in the water." [2]

So far as the OP's question is concerned, why take the risk? The cost
of the approved inhibitor is surely tiny compared to what's been spent
on the rest of the system. Also using non-approved products might
invalidate the manufacturer's guarantee on the boiler.


[1] http://www.fernox.com/?cccpage=mb_1&sub=1
[2] http://www.fernox.com/?cccpage=cor_inh&sub=2

--
Andy

In article ,
writes:
Hi all,

I am just finishing off the installation of a new C/H system. The tank
and boiler instructions recommend Fernox-brand inhibitor, but there
are lots of other inhibitors on the market. Will I see a noticeable
difference between a cheaper inhibitor like Triple-X (http://
www.toolstation.com/messages.html?code=94504), and a more expensive
inhibitor like Fernox F1 or Sentinel X100? This is for a 300l heat-
bank system, so the difference in price between cheap and expensive
adds up. If the expensive stuff simply comes in a better class of
bottle, but contains a virtually identical liquid, then I may as well
get the cheap stuff!

I've never seen any comparison done between products (sometimes wondered
myself). It's an opportunity which is wide open to fake products which
are appearing too (mostly chinese).

One thing I recall Andy Hall did where he had to use the more expensive
versions with anti-freeze was to design in the ability to drain down
and capture the water, and use it to refill the system, thereby not
losing all the inhibitor if you need to drain down to fix a leak just
after installation. My be less practical with a large water content
though.

I might be inclined to fill with only one bottle for a few weeks (sort
of simulating situation near the end of the life of the inhibitor) so
that if you do need to drain down to fix any initial leaks, the loss is
limited. Then top up to full strength after some weeks of no leaks.

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

On Thu, 25 Sep 2008 12:30:13 +0000, Andrew Gabriel wrote:

I've never seen any comparison done between products

Then you haven't been following uk.d-i-y very closely! ;-)

Rod's already posted the link to the article in our very own wiki.



--
YAPH http://yaph.co.uk

Question Authority

Andy Wade wrote:
stuart noble wrote:

I don't think any of them contain anything much other than a mild
acid, like boric.

I'm no chemist but I think that's utter nonsense. For a start the pH of
Fernox MB-1 (probably still the most common inhibitor?) is given as 8.3
- 8.8 for the concentrate [1], so it's hardly acidic.

Sentinel x100 has a ph of 6.4, and the main ingredient is boric acid.
Hardly utter nonsense

wrote

Hi all,

I am just finishing off the installation of a new C/H system. The tank
and boiler instructions recommend Fernox-brand inhibitor, but there
are lots of other inhibitors on the market. Will I see a noticeable
difference between a cheaper inhibitor like Triple-X (http://
www.toolstation.com/messages.html?code=94504), and a more expensive
inhibitor like Fernox F1 or Sentinel X100? This is for a 300l heat-
bank system, so the difference in price between cheap and expensive
adds up. If the expensive stuff simply comes in a better class of
bottle, but contains a virtually identical liquid, then I may as well
get the cheap stuff!

thanks,

dan.

Without a doubt go Fernox.
As others have said the cost is minimal when considered alongside the
capital cost of just an overhaul, let alone major works.
They have a good technical department too if you are in any doubt over which
product(s) to use.

From experience, I spent a lot of time trying to resolve issues with my
heating system and in the course of this used both Sentinel and Fernox.
I think most agree these are the most respected products - wish Andy Hall
was here as I know he would certainly back this up!

I found of the two that my system ran noticably quieter with the Fernox (I'm
talking boiler noise here not un-bled air).

HTH

Phil

stuart noble wrote:

Sentinel x100 has a ph of 6.4, and the main ingredient is boric acid.
Hardly utter nonsense

COSHH data sheets are on the Screwfix website. The hazardous
ingredients for X100 are listed as benzotriazole (2.5%) and sodium
molybdate (2.5 - 25%). No mention of boric acid, but that might not
count as hazardous. The pH is given as 6.7,

For MB-1 the only listed ingredient is triethanolamine (1 - 5%) and the
stated pH is 7.2.

So with data on only two products we can conclude that they aren't all
acidic and that at least two products contain ingredients other than
just a mild acid. So not utter nonsense - apologies - but not correct
either.

--
Andy

Andy Wade wrote:
stuart noble wrote:

Sentinel x100 has a ph of 6.4, and the main ingredient is boric acid.
Hardly utter nonsense

COSHH data sheets are on the Screwfix website. The hazardous
ingredients for X100 are listed as benzotriazole (2.5%) and sodium
molybdate (2.5 - 25%). No mention of boric acid, but that might not
count as hazardous. The pH is given as 6.7,

For MB-1 the only listed ingredient is triethanolamine (1 - 5%) and the
stated pH is 7.2.

So with data on only two products we can conclude that they aren't all
acidic and that at least two products contain ingredients other than
just a mild acid. So not utter nonsense - apologies - but not correct
either.


It's what happens when non-chemists discuss chemistry :-)
I doubt whether triethanolamine is an "active" ingredient when it comes
to corrosion, AFAIK it just maintains alkalinity. No idea why Fernox is
alkaline and Sentinel is acidic though.