One for the CH experts...
I've just had a complete new system installed (Baxi 105e combi, 10
rads and TRVs on all bar bathroom rad) but the installer has not put
any inhibitor in the system. The Baxi manual says that a suitable
inhibitor should be used and failure to do so "may invalidate the
warranty". The installer says that:
a) it's a sealed system so no air can get in to cause any corrosion
b) I live in a soft water area so the water is "non-agressive" anyway
(presumably referring to scale build up as opposed to corrosion?)
c) there's a school of thought that says that inhibitors can "cause
more harm than good"
d) he hasn't got any inhibitor in his own home system either!
So, do I take his advice and leave well alone or go and get one of
those Fernox "injector" tubes of inhibitor and apply it myself?
Absolutely, definitely, with no doubt whatsoever, ensure that you install
inhibitor. He is a moron, or is just looking towards his long term income
from replacing all your radiators in three years time.
Interesting that the CORGI guy who I used to test & then issue safety
certifaicate for my new place, also NEVER, EVER installs inhibitor.
He thinks it is a total waste of money, just a con by the like of Fernox.
This is not a way of incresing his income as I did the install myself, and
he didn't charge for the saftey inspectionm & certificate issue (friend of
I have a Thermal store, pressurised ... with underfloor heating, I did
install inhibitor in the boiler primary circuit, and in the UFH cicuit.
Putting the inhibitor in the primaries had me stumped for a while ... how
the hell could I put it it in? unlike the injector cartridge for the UFH,
the boiler cct was a litre of liquid ..... luckily found a way ... unscrewed
the auto air-vent on the top of the store and poured it in the store.
Then he's a typical CORGI cretin. ;-)
I'd like to hear from anyone who has used inhibitor and kept it up to
strength who's had their rads corrode through - I'm not talking about
outside surface rust.
And all cars these days insist you use inhibitor in the cooling system.
You ignore this at your peril.
*Despite the cost of living, have you noticed how it remains so popular?
Dave Plowman firstname.lastname@example.org London SW 12
On 12 Dec 2003 09:39:54 -0800, email@example.com (Andy) wrote:
There will already be some in there and corrosion can take place
anaerobically as well.
Scale build up is a hard water phenomenon and won't happen in any
heating system, sealed or not as long as there are not leaks which
cause new water to be added. Once any calcium and magnesium salts are
deposited, that's it. Some soft water is mildly acidic, however.
The one that he and his mates (plumbers all call each other 'mate' -
it's a requirement) attend at the plumber's merchants every morning as
they buy their materials for the day and swap old wives tales and how
they can make more money by having to replace radiators.
He can buy his radiators at trade prices.
You can usefully add the contents of one of these as the cheapest
insurance policy that you can buy. In fact it's not insurance, but
return on investment.. If you are going to do this properly, the
water should be tested each year and more inhibitor added if
necessary. Typically this will be every 2-3 years.
The gel stuff works well, but I would recommend not using the
instructions on the box where it tells you to inject against the
pressure. This can get messy,
A better solution is to pick a large radiator and turn off both
valves, noting the position of the lock shield valve.
Place a vessel under one radiator valve union and carefully undo it to
drain out 2-3 litres of water. Careful because if the water is
rusty, it will stain. Add the contents of the tube through the
injector refit the vent and open the valves. Run the heating for a
while and then bleed this radiator.
I should mention that before doing this that it would be a very good
idea to flush the system. If the installer doesn't believe in
inhibitor he probably didn't bother to do that either. There could
well be acidic flux residue in there. All you need to do is to drain
and flush the system through using the filling loop. Fernox make a
gel flushing agent called Superfloc which you can then add as above.
Run this with the system hot for a few hours and then drain and flush
thoroughly. Add water and inhibitor.
In my experience soft water was more of a problem...
I bought an 8 year old house in a very soft water area. Shortly after moving
in I found most of the rads were weeping at the back where they were spot
welded and had to replace them..
Inhibitor in a sealed system is required because of the dissimilar metal
used in the system, ferrous being the biggest offender. If the system has
no ferrous, you can get away without using inhibitor. I know of some
systems in soft water areas which have copper skirting heaters, copper heat
exchanger boilers, bronze pump, etc, and they are fine after 30 years. I
know of one system in a soft water area using a Glow Worm Spacesaver, rads,
F&E tank, etc, which has been going for 24 years with no inhibitor, and all
original equipment except in its 3rd pump.
I would always recommend using inhibitor.
Checked by AVG anti-virus system (http://www.grisoft.com ).
Version: 6.0.548 / Virus Database: 341 - Release Date: 05/12/2003
Many thanks for all the advice, given me food for thought. I'll apply
inhibitor, taking extra care with the "gel stuff" as advised.
Presumably applying it approx 8 weeks after system first in use is OK?
I suppose I should have got wise to this guy earlier - during the work
things that you might have reasonably assumed would be included (given we
were paying over the going rate) seemed to become a chargeable "extra".
Anyway, live and learn.
Are you sure that the system was properly flushed? If not, then I
would also invest in some Fernox Superfloc gel as well and put that in
first. Run it hot for a few hours and then drain and flush. Put in
the inhibitor and fill.
To email, substitute .nospam with .gl
HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here.
All logos and trade names are the property of their respective owners.