My house is 20 years old - Worcester Heatslave HighFlow Boiler - microbore
pipes to Maxtwin radiator valves (but it works!).
Any comments on best for value additive will be appreciated. (I have always
had an additive in)
I've always used Fernox MB-1 or Superconcentrate gel in systems for
over 30 years. Typically it's one dose per 2 years to maintain the
required level at a test from what I've found.
The current system is now 20 years old and remains as clean as a whistle.
There certainly have been nail in jar tests done by people in this
group and it has been found that the cheap products don't perform as
The economics are straightforward enough. Fernox or Sentinel cost
£20-25 for a treatment, so on average about £15 a year.
The cheap unbranded stuff costs around £8, so being generous £5/year.
So the discussion is about saving £10 a year on a system that would
cost £3000 or more to replace.
I am very surprised that anyone would even ask the question as to
whether it's worth taking such a risk vs, using known good products.
The discussion becomes one of chancing some unknown product and saving
£10 per annum at the risk of wrecking a £3k heating system.
Fernox and Sentinel are known good products that have been on the
market for decades and have a proven track record.
The rip off would be the person themselves using something of unknown
track record and quality and then wondering why the system has
> The economics are straightforward enough. Fernox or Sentinel cost
> £20-25 for a treatment, so on average about £15 a year.
Gledhill recommend Fernox over Sentinel as it has anti-biology growth
> Gledhill recommend Fernox over Sentinel as it has anti-biology growth
I would agree on this one. I generally use Fernox MB1. If you buy from
Screwfix, I think MB1 is about £18. Sentinel seems ok, but I don't know if
it would be a bad thing to topup with different 'brands' of inhibitor.
HRPC or whatever they are called now stock Kamco branded inhibitor for
about £10 in the same size containers that Sentinel use. Kamco say on their
training course that using some inhibitors is worse that none at all.
Geosolar, Cambridge. Gas central heating installations.
High quality ATAG boilers www.geosolar.co.uk
> There certainly have been nail in jar tests done by people in this group
> and it has been found that the cheap products don't perform as well.
Yes, I remember the photos being posted on this ng - I'm sure googling
will find them if the 'tester' himself doesn't stand up!
I think it was Andrew Gabriel but not certain.
> The whole thing's a rip off because AFAIK the main ingredient in
> Sentinel (and possibly the rest)is boric acid, which is dirt cheap and
> pretty easy to get hold of
Boric Acid? Are you sure? Are you a chemist or something?
The final pH has to be alkaline so I don't think an acid would be
I think it's sodium molybdate in Sentinel & Fernox. I also know of
sodium sulphite being used as an oxygen scavenger and sodium hydroxide
being used to adjust the pH to alkaline. Nitrites are used in cheap
stuff allegedly. However, they won't disclose what the active
ingredients are, so you can't test it without paying them a huge wad
of wonga for their test kits. Huge volumes of inhibitors must be
discharged into the drains and renewed every year when a simple test
of the levels and a top-up of the active ingredients would be most
cost effective. All water treatment companies are similar, selling
'Super Formula X' for mega-bucks when they purchase it as cheap bulk
chemicals. It has always been thus. The cost of corrosion damage makes
the inhibitors a sound investment, despite this.
I don't think the nail-in-jar test is very effective, the corrosion
rate depends on the rate at which oxygen is getting into the solution,
so removing the solution from the system does not make for an good
test. A corrosion coupon rack is the proper job way to do it (http://
>On 6 Sep, 16:35, Stuart Noble <stuart_nobleNOS...@ntlworld.com> wrote:
>> The whole thing's a rip off because AFAIK the main ingredient in
>> Sentinel (and possibly the rest)is boric acid, which is dirt cheap and
>> pretty easy to get hold of
>Boric Acid? Are you sure? Are you a chemist or something?
Boric acid seems to be very difficult to get hold of nowadays. Once
upon a time (a year or two ago) you could buy it easily from any local
'chemist', but apparently it became popular for preparing certain
"drugs ;-(", hence most local pharmacies have discontinued it -
another example of the nanny-state in action.
I'm sure it'll be available on-line from your friendly e-meds/Viagra
(they are only a few miles down the road from me)
their products are good quality
No, but I can read a safety data sheet
> The final pH has to be alkaline so I don't think an acid would be
> involved. IANAC.
Sentinel X100 is PH6.4 IIRC
> Frank Erskine wrote:
>> I'm sure it'll be available on-line from your friendly e-meds/Viagra
> Plenty on EBay, and probably available at garden centres.
No that's for making plants grow, not other things.
Fernox seem to have 3 similar offerings (at Screwfix)
Can't really see the difference!
I have used MB 1 before and Sentinel products.
I guess I will get MB1
MB-1 is the product suitable for standard systems and has been on the
market for donkey's years.
F1 has the same characteristics and can be used interchangeably with
MB-1 unless you want to use the gel superconcentrate in a sealed system
for convenience. F1 is a newer product.
Alphi-11 is a very diferent product. Apart from being an inhibitor,
it has an antifreeze component. Commonly it's used in solar heating
systems. I've used it in a secondary circuit to my workshop because
of the risk that the circuit could reach temperatures below 0 degrees
if the circuit were turned off or heat supply wasn't there. It's a
lot more expensive than MB-1 because a larger quantity is required -
e.g. I run that circuit with 20% of Alphi-11.
Dim the lights, and impress Madam with the size of your cucumber...
Boric acid has a variety of uses. Buy it where you like. Buy it from
Sentinel as a 5% solution in water if you prefer
I used to think the brain was the most interesting part of the body
- until I realised what was telling me that
> I would agree on this one. I generally use Fernox MB1. If you buy from
> Screwfix, I think MB1 is about £18. Sentinel seems ok, but I don't know if
> it would be a bad thing to topup with different 'brands' of inhibitor.
Don't mix inhibitors. Fernox is better for open vented systems. Sentinel is
fine for sealed systems, so saving money.
Going by those piccies Sentinel looks the best.