Couple of months back I had to drain the CH system to remove an existing
radiator and cap off the flow & return, while extension works (new kitchen)
are being carried out. When refilling the system, although I had a bottle of
Fernox (about £15), I thought I wouldn't put it in for a couple of months,
until I had refitted the radiator and added one in a new location, which
would involve draining down alll over again, and wasting the inhibitor.

With the colder weather upon us, the central heating has been switched on
again and it's going to be another month or two before the radiators in
question are reconnected. How long is it acceptable to run the system
without inhibitor in it. If necessary I could put it in this weekend, but if
it's not reeally necessary for a couple of months then I'll wait.

Thanks


--
KEVIN BRADY, Oxford
_____________________
replies to newsgroup only
mail to reply address is automatically deleted from server

On Fri, 4 Nov 2005 15:00:01 +0000 (UTC), "Kevin Brady"
wrote:

With the colder weather upon us, the central heating has been switched on
again and it's going to be another month or two before the radiators in
question are reconnected. How long is it acceptable to run the system
without inhibitor in it. If necessary I could put it in this weekend, but if
it's not reeally necessary for a couple of months then I'll wait.

My central heating system is over 30 years old and for the last 6
years (At least) has run without inhibitor. It's possible it's never
had inhibitor in it.

As long as you put the Fernox in next spring I personally wouldn't
worry.

sponix

With the colder weather upon us, the central heating has been switched on
again and it's going to be another month or two before the radiators in
question are reconnected. How long is it acceptable to run the system
without inhibitor in it. If necessary I could put it in this weekend, but
if
it's not reeally necessary for a couple of months then I'll wait.

It depends. Some people run without inhibitor, although can be a disaster if
serious corrosion sets in. I'd probably not want to run several months
without it, although I would be happy for a week if there was no chance of
freezing. You could buy some "value" inhibitor in the meantime, particularly
if a "couple of months" turns into "a few years" due to the chronic tuit
shortage.

Toolstation will do you a dose of inhibitor for 3.35 inc VAT.

http://www.toolstation.com/index.html?code=94504

Christian.

In an earlier contribution to this discussion,
sPoNiX wrote:

On Fri, 4 Nov 2005 15:00:01 +0000 (UTC), "Kevin Brady"
wrote:

With the colder weather upon us, the central heating has been
switched on again and it's going to be another month or two before
the radiators in question are reconnected. How long is it acceptable
to run the system without inhibitor in it. If necessary I could put
it in this weekend, but if it's not reeally necessary for a couple
of months then I'll wait.

My central heating system is over 30 years old and for the last 6
years (At least) has run without inhibitor. It's possible it's never
had inhibitor in it.

As long as you put the Fernox in next spring I personally wouldn't
worry.

sponix

AIUI, it depends on the composition of your tap water. You *may* get away
without inhibitor, but it's always *safest* to use it.

To the OP: Is yours a vented system? If so, can't you save the water and put
it back into the header tank so as not to lose the inhibitor? That's what I
do.
--
Cheers,
Set Square
______
Please reply to newsgroup. Reply address is invalid.

To the OP: Is yours a vented system? If so, can't you save the water and put
it back into the header tank so as not to lose the inhibitor? That's what I
do.

You can even if it's a sealed system.

For my secondary circuit that provides heating to my workshop, I
decided to use an inhibitor containing an anti-freeze - Fernox
Alphi-11. To achieve what I felt to be a good margin of minimum
temperature, several containers were needed and it is fairly expensive.
I therefore fitted two filling points. One is in the house and
mains water can be used in the normal way. The other is in the
workshop together with a drain point. The expansion vessel is also in
the workshop. I can isolate the garage part of the circuit from the
house with two valves.

I made up a filling gizmo consisting of a garden sprayer with several
plumbing fittings attached to the wand to adapt it to fit the filling
point. I can drain part or all of the system and collect the water.
I can then pump it back in using the sprayer. There is enough oomph
in these things than I can just about get 2 bar, so in effect I can
repressurise using the old water.

Since the sprayer is about the same cost as a dose of regular Fernox,
it may well be worth something like this during extended plumbing
operations.

Thanks everyone for the advice - its a vented system, but I think a few quid
on some value inhibitor will protect my conscience for the next few months.

Wishing you a good weekend.


--
KEVIN BRADY, Oxford
_____________________
replies to newsgroup only
mail to reply address is automatically deleted from server

"Kevin Brady" wrote in message
...
Couple of months back I had to drain the CH system to remove an existing
radiator and cap off the flow & return, while extension works (new
kitchen) are being carried out. When refilling the system, although I had
a bottle of Fernox (about £15), I thought I wouldn't put it in for a
couple of months, until I had refitted the radiator and added one in a new
location, which would involve draining down alll over again, and wasting
the inhibitor.

With the colder weather upon us, the central heating has been switched on
again and it's going to be another month or two before the radiators in
question are reconnected. How long is it acceptable to run the system
without inhibitor in it. If necessary I could put it in this weekend, but
if it's not reeally necessary for a couple of months then I'll wait.

Thanks


--
KEVIN BRADY, Oxford
_____________________
replies to newsgroup only
mail to reply address is automatically deleted from server


When I tried using Fernox I had nothing but trouble. The sealing washers on
the radiator vent valve fittings all disintigrated over a period of time and
started seeping. I drained the stuff out and re-filled the system with
fresh water. My understanding is that a given volume of water carries only
so much oxygen and once it has reacted with the inner surfaces of the
heating system then no further corrosion can take place anyway.

Jerry

My understanding is that a given volume of water carries only
so much oxygen and once it has reacted with the inner surfaces of the
heating system then no further corrosion can take place anyway.

That is true for a sealed system as long as there are no leaking joints
which can achieve negative pressure relative to the atmosphere. This
can happen if the system pressure is allowed to fall to much.

For open vented systems, if there is any amount of pump over or suck
down, then oxygen will be rapidly introduced. Even of "perfect", the
header tank is exposed to the air and air will dissolve. Given that
there will be expansion and contraction, there will be introduction of
oxygen.

There should be no reason for vent valves to fail. It would be worth
fitting a different type.

Omitting a good quality inhibitor is inviting an expensive replacement
of radiators later.

In article . com,
"andy hall" writes:
My understanding is that a given volume of water carries only
so much oxygen and once it has reacted with the inner surfaces of the
heating system then no further corrosion can take place anyway.

That is true for a sealed system as long as there are no leaking joints
which can achieve negative pressure relative to the atmosphere. This
can happen if the system pressure is allowed to fall to much.

Actually, it's worse than this. Even when the water pressure
is higher than atmospheric pressure, oxygen will still enter
the system through a leak when the partial pressure of oxygen
in the water is lower than than in air, and this will nearly
always be the case as the oxygen in the system will be continuously
removed by reaction with iron (rusting). A leak which is too small
to leak enough water out to notice will leak air in much faster
(even when water pressure is higher than air pressure). To an
oxygen molecule just outside the leak, your heating system will
look like it's nearly a vacuum, inviting it in. Even if you don't
think you have any leaks, things like the stuffing boxes on valve
shafts and O-Ring seals on moving actuator shafts aren't going to
be completely gas-tight, even if they appear to be water-tight.
The oxygen will even leak in through the walls of some plastic
pipe and fittings.

You can get a rough idea of the corrosiveness of your water
by draining off a small jar full from a bleeding nipple, and
leaving a small iron nail in it, with the lid sealed closed.
If the system has inhibitor in it which is not all used up,
the nail will stay shiny. Otherwise it will rust on the surface,
until it has used up all the oxygen in the water. (Don't use
a large nail -- the jar might not hold enough oxygen to show
rust, even it it's saturated.)

Omitting a good quality inhibitor is inviting an expensive replacement
of radiators later.

--
Andrew Gabriel

How long is it acceptable to run the system
without inhibitor in it.


I had always used Fernox .... when I had my new system commissioned, my
CORGI man (been in business 30+ yrs) told me he NEVER adds inhibitor, it is
not needed and just a marketing ploy.

Interesting view form a professional.

Rick

I had always used Fernox .... when I had my new system commissioned,
my CORGI man (been in business 30+ yrs) told me he NEVER adds
inhibitor, it is not needed and just a marketing ploy.

Interesting view form a professional.

Rick

I find Andrew's explanation above (on *my* reader) to be somewhat more
convincing.

mike

INHIBITORS.....FERNOX....SENTINAL ETC

In general terms they hold good for around 15 years with 3 complete draindowns.....IT IS NOT GOOD TO ADD CHEMICALS TO YOUR SYSTEM unless there is a specific reson...If you add fernox incorrectly it will solidify and block your cold feed...its will then eat away at your pipe causing a water leak..seek advise from a qualified gasman....if you really want to enhance the lifetime of an old system..POWER FLUSH IT

In article ,
says...

How long is it acceptable to run the system
without inhibitor in it.


I had always used Fernox .... when I had my new system commissioned, my
CORGI man (been in business 30+ yrs) told me he NEVER adds inhibitor, it is
not needed and just a marketing ploy.

Interesting view form a professional.

A professional who will benefit from all those systems that need repair
or replacement because they didn't use inhibitor?

Rick Hughes wrote:
How long is it acceptable to run the system
without inhibitor in it.


I had always used Fernox .... when I had my new system commissioned, my
CORGI man (been in business 30+ yrs) told me he NEVER adds inhibitor, it is
not needed and just a marketing ploy.

Interesting view form a professional.

Rick

It's certainly interesting, no question about that.

From my own experience inhibitor is essential if you have steel rads.
Without it you end up with loads of crap in the system.

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.

In article ,
"Rick Hughes" writes:

How long is it acceptable to run the system
without inhibitor in it.

I had always used Fernox .... when I had my new system commissioned, my
CORGI man (been in business 30+ yrs) told me he NEVER adds inhibitor, it is
not needed and just a marketing ploy.

Well, that voids the manufacturers' warantees on most new boilers.
Does he offer his own warantee instead?

Interesting view form a professional.

Not really.

--
Andrew Gabriel

In article ,
Rick Hughes wrote:
I had always used Fernox .... when I had my new system commissioned, my
CORGI man (been in business 30+ yrs) told me he NEVER adds inhibitor,
it is not needed and just a marketing ploy.

Interesting view form a professional.

Well, of course. It's not in his interest to have a system last a long
time. Just beyond a reasonable time for a legal warranty.

--
*Time is what keeps everything from happening at once.

Dave Plowman London SW
To e-mail, change noise into sound.

In article ,
gastec wrote:
In general terms they hold good for around 15 years with 3 complete
draindowns.....IT IS NOT GOOD TO ADD CHEMICALS TO YOUR SYSTEM unless
there is a specific reson.

The reason is to prevent corrosion to the steel parts like the rads.

..If you add fernox incorrectly it will solidify and block your cold
feed...its will then eat away at your pipe causing a water leak.

So a corrosion inhibitor causes corrosion? Think you might be able to sue
if it did.

.seek advise from a qualified gasman.

Oh dear. The likes of you?

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

Ah. Now the plug for a vastly overpriced service.

If you've used the correct inhibitor there won't be anything to 'power
flush' out.

--
*Could it be that "I do " is the longest sentence? *

Dave Plowman London SW
To e-mail, change noise into sound.

In article ,
writes:

I wonder how long fernox lasts? I top up the system manually, and probably
add no more than 5L per year of water.

The fact you top up at all means you have a leak, and air will
be leaking in (quite possibly at a faster rate than the water
leaks out). Topping up once a year is not serious enough to
rip up all the floorboards to find it, but the leak will be
slowly using up the inhibitor.

Do the nail test I mention in my other post.

--
Andrew Gabriel

Dave Plowman (News) wrote:

This is a brief summary of the accumulated knowledge/ignorance
(delete as you think appropriate) I have acquired in the course of 20+
years in building services. I'm not a chemist, there's a lot more
to corrosion science, but this is adequate for most purposes.


There are 2 main varieties of corrosion which affect heating systems;
dissolved oxygen and galvanic corrosion.

DISSOLVED OXYGEN
Dissolved oxygen will corrode the inner surface of radiators and
reduce them to black, stick magnetite sludge. The oxygen can get into
the water by a variety of routes, e.g., the exposed water surface in a
feed & expansion tank, or leaks through valve glands caused by the low
partial pressure of the oxygen in the water, mentioned by AG above. A
water leak will introduce dissolved oxygen in the fresh make-up water.
fresh water with dissolved oxygen. 'Pumping over' will introduce
large quantities of oxygen into the water and will ruin the system
within a few years.

Plastic pipes are permeable to oxygen and some oxygen will enter the
system through the pipe walls. This is it relevant with car cooling
systems, which generally have a lot of flexible, non-barrier hoses.
Pipes with an oxygen barrier will reduce the permeability of the pipe
walls to a negligible level, but they do completely stop the oxygen
absorption.

The inhibitor solution deals with the dissolved oxygen by having an
oxygen scavenger component. The scavenger reacts with the oxygen before
the oxygen reacts with the steel radiators. The scavenger can be a
number of chemicals, typically sodium sulphite. The sulphite should be
maintained at nlt 20 to 50 ppm; titration teat kits are available to
monitor the concentration.
O2 + 2SO3= 2SO4

The rate of the sulphite depletion indicates the rate at which oxygen
is being absorbed


GALVANIC CORROSION

Galvanic/ bi-mettalic corrosion normally takes place between the copper
pipes and the steel radiators. A corrosion cell will exist between any
two metals that are electrically connected and immersed in a suitable
electrolyte. A voltage will be created between the two metals and ions
will be stripped from the anode, the less-noble of the two metals, like
electro-plating in reverse. Hydrogen is generated at the anode (I
think), the steel radiator in this instance. The hydrogen is insoluble
and can be identified by collecting it in an upturned glass and
igniting it. The oxygen is dissolved and attacks the radiators, see
above.

The galvanic corrosion is dealt with by ensuring that the
electrolyte/water is alkaline pH7. Typically this is done by adding
caustic soda to neutralise any acids and adjust the pH to 8 or 9.

The rate of galvanic corrosion will be greatly increased if the water
is acidic. The main source of the acid, in new systems, is active flux,
which contains hydrochloric acid. This should be thoroughly flushed out
of the system but often the pre-commisioning flushing is inadequate or
is completely omitted. Excessive flux and the careless use of flux will
add to the problems.

Another source of acidic compounds is anti-freeze (AH please note). The
glycols in anti-freeze will degrade in the presence of heat and
dissolved oxygen to form acidic compounds. Bad anti-freeze can cause
truly spectacular corrosion. This is very relevant with car cooling
systems. Once the residual alkalinity is consumed, the coolant will
become increasingly acidic and galvanic corrosion will attack the metal
engine components. Usually the head gasket fails.


Chemical corrosion inhibitors are cheap. The steel components of a
heating system are costly and internal damage cannot be repaired.
Neglecting or omitting the corrosion inhibitors is the mother of all
false economies. Inhibitors will not stop existing corrosion problems
(leaks, pumping-over). You can overdose with inhibitors, but I don't
know what the effect would be.

my CORGI man (been in business 30+ yrs) told me he NEVER adds inhibitor, it is
not needed and just a marketing ploy.

He is not competent, he should stick to gas.

Interesting view form a professional.

He may be a technician, he is not a professional.

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

No. You'd only need to powerflush it if it had been neglected.
Powerflushing is unlikely to remove all the corrosion products. You
should maintain it and ensure that it never needs flushing. The above
strange opinions add to my suspicions about Corgi-registered
technicians.

Typo

titration teat kits are available
should be
titration test kits are available.

My mind must have been elsewhere after writing titration.

In message , gastec
writes

With the colder weather upon us, the central heating has been switched
on
again and it's going to be another month or two before the radiators
in
question are reconnected. How long is it acceptable to run the system
without inhibitor in it. If necessary I could put it in this weekend,
but if
it's not reeally necessary for a couple of months then I'll wait.



INHIBITORS.....FERNOX....SENTINAL ETC

In general terms they hold good for around 15 years with 3 complete
draindowns.....IT IS NOT GOOD TO ADD CHEMICALS TO YOUR SYSTEM unless
there is a specific reson...If you add fernox incorrectly it will
solidify and block your cold feed...its will then eat away at your pipe
causing a water leak..seek advise from a qualified gasman....if you
really want to enhance the lifetime of an old system..POWER FLUSH IT


.... And they let people like this anywhere central heating systems ?


--
geoff

"raden" wrote in message
...
In message , gastec
writes

With the colder weather upon us, the central heating has been switched
on
again and it's going to be another month or two before the radiators
in
question are reconnected. How long is it acceptable to run the system
without inhibitor in it. If necessary I could put it in this weekend,
but if
it's not reeally necessary for a couple of months then I'll wait.



INHIBITORS.....FERNOX....SENTINAL ETC

In general terms they hold good for around 15 years with 3 complete
draindowns.....IT IS NOT GOOD TO ADD CHEMICALS TO YOUR SYSTEM unless
there is a specific reson...If you add fernox incorrectly it will
solidify and block your cold feed...its will then eat away at your pipe
causing a water leak..seek advise from a qualified gasman....if you
really want to enhance the lifetime of an old system..POWER FLUSH IT


... And they let people like this anywhere central heating systems ?

Maxie, I do agree with you. 15 year? With 3 draindowns? that is 5 years.

"Rick Hughes" wrote in message
...

How long is it acceptable to run the system
without inhibitor in it.

I had always used Fernox .... when I had my new system commissioned, my
CORGI man (been in business 30+ yrs) told me he NEVER adds inhibitor, it
is
not needed and just a marketing ploy.

Interesting view form a professional.

That depends on the water in your area. I have seen rads in London last 5
years without inhibitor, and rads still fine after 26 years in sof****er
areas.

wrote in message ...
On 5 Nov,
Rob Morley wrote:

In article ,
says...

How long is it acceptable to run the system
without inhibitor in it.


I had always used Fernox .... when I had my new system commissioned,
my
CORGI man (been in business 30+ yrs) told me he NEVER adds inhibitor,
it
is not needed and just a marketing ploy.

Interesting view form a professional.

A professional who will benefit from all those systems that need repair
or
replacement because they didn't use inhibitor?

It was suggested by mine that I didn't need it in a sealed system, but If
I really wanted to to add it after 6 months use. I did so 12 years ago
and
so far have had no (major) problems.

I wonder how long fernox lasts? I top up the system manually, and
probably
add no more than 5L per year of water.

Top it up now.

In article ws.net,
Doctor Drivel wrote:
That depends on the water in your area. I have seen rads in London last
5 years without inhibitor, and rads still fine after 26 years in
sof****er areas.

Please explain the chemistry behind this statement.

Not that I'll hold my breath.

--
*I'm out of my mind, but feel free to leave a message.

Dave Plowman London SW
To e-mail, change noise into sound.

Dave Plowman (News) wrote:

That depends on the water in your area. I have seen rads in London last
5 years without inhibitor, and rads still fine after 26 years in
sof****er areas.

Please explain the chemistry behind this statement.

It is easy. Drivel installed the rads in London and used a supersize
bucket of active flux. He was called back repeatedly, but they'd all
failed within 5 years.

The 26 year old rads were installed by someone competent when Drivel
was a lad and are still fine.

Drivel thinks it must have been the water. That clear it up?

In article .com,
Aidan wrote:
That depends on the water in your area. I have seen rads in London last
5 years without inhibitor, and rads still fine after 26 years in
sof****er areas.

Please explain the chemistry behind this statement.

It is easy. Drivel installed the rads in London and used a supersize
bucket of active flux. He was called back repeatedly, but they'd all
failed within 5 years.

The 26 year old rads were installed by someone competent when Drivel
was a lad and are still fine.

Drivel thinks it must have been the water. That clear it up?

;-)

My brother lives in a soft water area - Aberdeen - and has had many of his
rads replaced through corrosion. BG service contract and no inhibitor.
I'm in London and my system is older - with Thermapanel rads which some
say aren't too robust corrosion wise - but no problems at all in 30 years.
Inhibitor changed about every 5 years - and on draining down the water
looks reasonably ok. Certainly not black. And this with an open vented
system.

--
*When the chips are down, the buffalo is empty.

Dave Plowman London SW
To e-mail, change noise into sound.

In article ,
"Dave Plowman (News)" writes:

My brother lives in a soft water area - Aberdeen - and has had many of his
rads replaced through corrosion. BG service contract and no inhibitor.
I'm in London and my system is older - with Thermapanel rads which some
say aren't too robust corrosion wise - but no problems at all in 30 years.
Inhibitor changed about every 5 years - and on draining down the water
looks reasonably ok. Certainly not black. And this with an open vented
system.

Radiators seem to have been gradually turned from capital
purchases into consumables. My parents' heating system
(installed by my dad) ran from late 1950's through to
2000 with no inhibitor. All the original radiators (which
look exactly like today's plain stelrads, but no fins)
are all still fine, with no rust or leaks whatsoever, so
inhibitor-free life is in excess of 40 years. In 1964,
two extra radiators were added, and these both failed
about 20 years later. In 1970, one extra radiator was
added and this failed after 10 years.

So we can plot radiator lifetime without inhibitor as
a function of year of manufacture something like this:

Year of manufacture Expected lifetime
1958 42 years
1964 20 years
1970 10 years

It would seem the industry cleverly worked out how to
turn radiators into consumables throughout the 1960's,
and create the need for inhibitor (another consumable).

--
Andrew Gabriel

Well it is a view from a 'Professional' and I posted it as many
respect the views of Professionals. (and indeed pay for them) ... and
the way legislation is going the CORGI man and the NICEIC man are
going to have a lot more say in what goes on in peoples houses.

BTW - I did not follow his comments, and although I have a sealed
thermal store I did dose with correct Inhibitor.

Rick

I looked at his business card - he is also a member of IDHE (now called
IDHEE) - "The IDHEE is still the pre-eminent professional body for the
domestic heating engineer. The Institute aims to promote energy
efficient domestic central heating components and the installation of
safe and efficient systems. "

and also a member of IPHE - Institute Plumbing & Heating Engineers .

So I would say that from a professional Standing point of view he fits
what most people would expect as 'meeting the standard' but as I
mentioned in previous post, I did not follow his advice and used
Inhibitor.
I had installed the system myself, and he was commissioning the system
and issuing the gas safety certificate.

However somebody who is not well versed with heating systems, may well
follow the advice of "the Professional" and not use the inhibitor.

Rick

"Dave Plowman (News)" through a haze of senile
flatulence wrote in message ...
In article ws.net,
Doctor Drivel wrote:
That depends on the water in your area. I have seen rads in London last
5 years without inhibitor, and rads still fine after 26 years in
sof****er areas.

Please explain the chemistry behind this statement.

Richard Cranium, why?

Not that I'll hold my breath.

Please hold your breath for a few days.

In article ws.net,
Doctor Drivel wrote:
That depends on the water in your area. I have seen rads in London
last 5 years without inhibitor, and rads still fine after 26 years
in sof****er areas.

Please explain the chemistry behind this statement.

Richard Cranium, why?

So the usual don't know?

Stick to quoting brochures.

--
*The hardness of the butter is proportional to the softness of the bread *

Dave Plowman London SW
To e-mail, change noise into sound.

"Kevin Brady" wrote in message
...
Couple of months back I had to drain the CH system to remove an existing
radiator and cap off the flow & return, while extension works (new kitchen)
are being carried out. When refilling the system, although I had a bottle of
Fernox (about £15), I thought I wouldn't put it in for a couple of months,
until I had refitted the radiator and added one in a new location, which
would involve draining down alll over again, and wasting the inhibitor.

Did you actually completely drain the system, or would some water have remained?

If so you may still have some inhibitor.

My system survived a number of years without new inhibitor. Certainly much
longer than I intended!

There was very little sludge in the bottom of the radiators when I did get
around to drains and re-filling the system.

--

Michael Chare

"Dave Plowman (News)" through a haze of senile
flatulence wrote in message
...
In article ws.net,
Doctor Drivel wrote:

That depends on the water in your area. I have seen rads in London
last 5 years without inhibitor, and rads still fine after 26 years
in sof****er areas.

Please explain the chemistry behind this statement.

Richard Cranium, why?

So the usual don't know?

Mr Cranium, will you tell us please? You appear to think you know. Give us
your views. Spill the beans. Well I'm sure you spilt them on your cardigan.

snip senility

In article ws.net,
Doctor Drivel wrote:
That depends on the water in your area. I have seen rads in
London last 5 years without inhibitor, and rads still fine after
26 years in sof****er areas.

Please explain the chemistry behind this statement.

Richard Cranium, why?

So the usual don't know?

Mr Cranium, will you tell us please? You appear to think you know.

You want someone else to 'explain' your theories? Figures.

--
*I must always remember that I'm unique, just like everyone else. *

Dave Plowman London SW
To e-mail, change noise into sound.

"Dave Plowman (News)" through a haze of senile
flatulence wrote in message ...
In article ws.net,
Doctor Drivel wrote:
That depends on the water in your area. I have seen rads in
London last 5 years without inhibitor, and rads still fine after
26 years in sof****er areas.

Please explain the chemistry behind this statement.

Richard Cranium, why?

So the usual don't know?

Mr Cranium, will you tell us please? You appear to think you know.

You want someone

Mr Cranium, will you tell us please? You appear to think you know.

snip senility

Rick wrote:
I looked at his business card - he is also a member of IDHE (now called
IDHEE) - "The IDHEE is still the pre-eminent professional body for the
domestic heating engineer. The Institute aims to promote energy
efficient domestic central heating components and the installation of
safe and efficient systems. "

and also a member of IPHE - Institute Plumbing & Heating Engineers .

So I would say that from a professional Standing point of view he fits
what most people would expect as 'meeting the standard' but as I
mentioned in previous post, I did not follow his advice and used
Inhibitor.
I had installed the system myself, and he was commissioning the system
and issuing the gas safety certificate.

However somebody who is not well versed with heating systems, may well
follow the advice of "the Professional" and not use the inhibitor.

He may be competent about every other aspect of heating systems but I
strongly disagree with his policy of not adding inhibitors; it must
cause considerable long-term damage to his installations, but the
warranty would be long expired before the damage was noticed. A
ha'porth of tar. I wonder what the IoP (now IoP&HE) Guide says; I may
have to look.

told me he NEVER adds inhibitor, it is
not needed and just a marketing ploy.

There is ceratinly an element of snake-oil marketing involved. No water
treatment company will volunteer to tell you the ingredients of their
solutions. I think you could make an effective home-brew inhibitor for
less than £1 a go, IF you had access to the chemicals.
They charge an exorbitant amount for their test kits, so most people
cannot just top-up as required, but tip in a whole bottle at £15 a go,
to be sure.

Excessive pH (9) can damage copper pipes I believe, but I've never
seen it happen.

You can do an interesting experiment about galvanic corrosion by
connecting a multi-meter between a piece of copper tube and steel pipe,
with their ends in a bucket of water. Plain mains water will cause a
very small PD between the two pipes. Adding a few drops of anything
acidic (lemon juice, vinegar) can increase the PD by a factor of 10.
Adding anything alkaline (caustic soda, oven cleaner) will reduce the
PD to 0.

Andrew Gabriel wrote:

Year of manufacture Expected lifetime
1958 42 years
1964 20 years
1970 10 years

It would seem the industry cleverly worked out how to
turn radiators into consumables throughout the 1960's,
and create the need for inhibitor (another consumable).

Active/acidic flux wasn't widely used, probably until sometime around
the '70s (?). Until then you had to use a passive flux and thoroughly
clean the pipe and fittings before soldering. A couple of old-timers
have told me that the raging corrosion, and the need for power flushing
to shift corrosion products obstructing the pipes, is something that
they rarely/never saw when they were youngsters. I suspect the active
flux is a major cause.

On Sun, 06 Nov 2005 05:02:49 -0800, Aidan wrote:


Andrew Gabriel wrote:

Year of manufacture Expected lifetime
1958 42 years
1964 20 years
1970 10 years

It would seem the industry cleverly worked out how to
turn radiators into consumables throughout the 1960's,
and create the need for inhibitor (another consumable).

Active/acidic flux wasn't widely used, probably until sometime around
the '70s (?). Until then you had to use a passive flux and thoroughly
clean the pipe and fittings before soldering. A couple of old-timers
have told me that the raging corrosion, and the need for power flushing
to shift corrosion products obstructing the pipes, is something that
they rarely/never saw when they were youngsters. I suspect the active
flux is a major cause.

Also the pipes were wider?

Generally from what I see most systems without inhibitor (or not topped
up) seem to survive (not flourish just survive) provided they are either
the sealed type or the conventional type in good order.

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

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.


--
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