Using Central heating WITHOUT fernox inhibitor
 

In article ,
writes:
Do the nail test I mention in my other post.

I'm trying that. The liquid coming out looked like lager (or re-cycled
lager!) but possibly slightly darker, certainly no dark sludge. The nail is
rust free overnight. How long do I leave it to show up problems?

A week should be more than enough.

If you have a second similar jar, do a control experiment.
Airate some water: 1/4 fill an old plastic drink bottle
with tap water, and shake vigourously to dissolve the air
in the water. You might notice the bottle collapse slightly
as the air is sucked into the water (the effect is more
noticable if you 1/2 or 3/4 fill the bottle, but this might
not airate the water so well). Now pour this into a second
jar with a nail, and close the lid. This nail should rust,
so when it has, if the other one hasn't, you can conclude
that the inhibitor is still working.

--
Andrew Gabriel

Using Central heating WITHOUT fernox inhibitor
 

On Sat, 05 Nov 2005 10:32:42 +0000, me9 wrote:

On 5 Nov,
"andy hall" wrote:

if you
really want to enhance the lifetime of an old system..POWER FLUSH IT


These messages brought to you by the Association of Heating Replacers
and Unnecessary Expensive Solutions for the Gullible.

I too was starting to think it was from someone indoctrinated by the
Monarch's dog's tail.

My view on power flushing is that sometimes it might be necessary to deal
with SYMPTOMS that must be dealt with separately.

Often other approaches to flushing are as effective such as using the
mains feed to flush each radiator in turn.

I'd prefer not to have one of the gadgets lest I'm considered in the same
league as a "Power Flushing fixes all problems I don't have a clue about"
member.


--
Ed Sirett - Property maintainer and registered gas fitter.
The FAQ for uk.diy is at http://www.diyfaq.org.uk
Gas fitting FAQ http://www.makewrite.demon.co.uk/GasFitting.html
Sealed CH FAQ http://www.makewrite.demon.co.uk/SealedCH.html

Using Central heating WITHOUT fernox inhibitor
 

Also the pipes were wider?

Don't think so, I had conventional pumped systems in mind, not
microbore.

Then really horrendous corrosion happens with open systems which faulty
layouts which pump over or suck air in.

True, a serial killer of radiators & clogger of pipes. Obvious and
avoidable.
A lot of people complain about repeatedly replacing radiators, but Mr.
Plumber hasn't tackled, or mentioned the cause. He regularly sells them
new rads and a powerflush too.


Occasionally systems can get into anaerobic corrosion. This is where the
oxygen is supplied by breaking down the water into hydrogen and oxygen.
The hydrogen gas then collects in a favourite radiator.
If I meet this I flush the system twice with water - draining it as far as
possible each time. The put in a double dose of inhibitor.
The causes of anaerobic corrosion seam to be:
1) trying to treat a
noisy boiler with acid and then failing to flush a neutralize it.
2) New systems which were not treated with a "new" system cleanser to
neutralize the flux.

I think this is what I know as galvanic/bi-mettalic corrosion. Caused
by acidic water, hydrogen in rads is a symptom. It is anerobic, in
that there is no need for air to enter the system.

Treating a boiler with acid descaler would only be necessary if the
boiler was scaled-up, but scaling would only occur if there was a leak
(leak in DHW cylinder coil, F&E tank incorrectly set-up & overflowing
when hot) and fresh water was coming in.

I once looked at a LTHW district heating system on a school site in
which the F&E tank (as big as a Transit) had been set up in the 60s so
that it was full when cold. I identified the cause in the 80s, when the
estimated repair costs were into 6 figures. Some of the cast-iron rads
had 40 sections, of which only 5 got hot; the other 35 were blocked
with sludge & scale. Descaling was recommended, but I left before they
did anything.