Hi,

Just found this newsgroup and discovered that there are more than 14,000
headers to download so forgive me if this question has already been asked

I have a gas central heating system with 6 heaters. It is at least 10 years
old. When I switch the heating off for a long time (over summer) there
appears to be a large build up of air in the system which gets stuck in the
pump which then needs to be bled. Scottish Gas came to fix and told me that
the build up of air was actually gas which was coming from various nasty
stuff inside the heaters and provided me with a hefty quote to flush out my
heating system. My question is this: can this be done diy (husband is
quite good at it) and if so what does he need in the way of equipment and
chemicals etc.

Thanks in advance

Margaret

"Margaret Macfarlane" wrote in message
...
Hi,

Just found this newsgroup and discovered that there are more than 14,000
headers to download so forgive me if this question has already been
asked

I have a gas central heating system with 6 heaters. It is at least 10
years
old. When I switch the heating off for a long time (over summer) there
appears to be a large build up of air in the system which gets stuck in
the
pump which then needs to be bled. Scottish Gas came to fix and told me
that
the build up of air was actually gas which was coming from various nasty
stuff inside the heaters and provided me with a hefty quote to flush out
my
heating system. My question is this: can this be done diy (husband is
quite good at it) and if so what does he need in the way of equipment and
chemicals etc.

Thanks in advance

Margaret

You should be running your central heating with a treatment such as Fernox
to inhibit corrosion.
Scottish Gas are probably correct about the cause, but also probably
mercenary about the cure.
Depending on your type of system (easiest if you have a system with a
header/expansion tank in the loft) you need to add a flushing compound and
run it for a few days, empty the system, then refill and add an inhibitor.
There are various interesting (and boring) discussions about flushing a
little further back in the NG - you can always use Google to search the NG
postings if you can't face downloading all the headers.
There should be at least one central heating FAQ floating about.
Try http://www.diyfaq.org.uk/ for starters.
No doubt the plumbing pros will point you to more resources.
HTH
Dave R

Margaret Macfarlane wrote:
Hi,

Just found this newsgroup and discovered that there are more than
14,000 headers to download so forgive me if this question has already
been asked

I have a gas central heating system with 6 heaters. It is at least
10 years old. When I switch the heating off for a long time (over
summer) there appears to be a large build up of air in the system
which gets stuck in the pump which then needs to be bled. Scottish
Gas came to fix and told me that the build up of air was actually gas
which was coming from various nasty stuff inside the heaters and
provided me with a hefty quote to flush out my heating system. My
question is this: can this be done diy (husband is quite good at it)
and if so what does he need in the way of equipment and chemicals etc.

Thanks in advance

Margaret

If Scottish Gas is anything to do with British Gas ( i.e. really Centrica)
they are useless & expensive.
Flushing was covered very well by Andy Hall in a posting.
Search on groups.google.co.uk for
Central +heating +flushing +Andy +Hall

Don't forget to put corrosion inhibitor in when the system is refilled.

"Margaret Macfarlane" wrote in
:

Hi,

Just found this newsgroup and discovered that there are more than
14,000 headers to download so forgive me if this question has already
been asked

Where have you been?

Scottish
Gas came to fix and told me that the build up of air was actually gas
which was coming from various nasty stuff inside the heaters and
provided me with a hefty quote to flush out my heating system.

They would, just like here
My question is this: can this be done diy (husband is quite good at it)
and if so what does he need in the way of equipment and chemicals etc.

Unless your problems are really dire, and they don't sound it,

drain a bit and add Fernox Superfloc (or one of the competitors ie
screwfix 16307)

Run the system for a few days

Drain and refill several times to flush out.

Fill up againn with additional Fernox MB-1 (or a competitor ie screwfix
13162)

Thats it

HTH

Mike R

On Sun, 31 Aug 2003 19:16:23 +0100, "Margaret Macfarlane"
wrote:

Hi,

Just found this newsgroup and discovered that there are more than 14,000
headers to download so forgive me if this question has already been asked

It has in various roundabout ways, but that's OK.



I have a gas central heating system with 6 heaters. It is at least 10 years
old. When I switch the heating off for a long time (over summer) there
appears to be a large build up of air in the system which gets stuck in the
pump which then needs to be bled.

The build up may well be hydrogen gas, rather than air. Hydrogen is
the product of corrosion of metal components in the system. In
addition to the pump, you would expect to find it gathering in the
tops of radiators. You can easily test whether it is hydrogen by
opening a radiator vent and applying a match or other flame.
Hydrogen burns with a pale blue flame.

Corrosion happens because of the reaction of the heating water and the
metals of the system. It can be almost completely prevented by
adding a corrosion inhibitor to the system and topping it up as
required - typically every three years, or if the system is drained.
At around £20 for the inhibitor (Fernox MB-1 is among the most
common), this is rather a cheap insurance policy.

Corrosion is accompanied by the heating water being brown or even
black and a build up of sludge in the system. A typical place for
sludging is in the bottom of radiators. The tell-tale sign is a
triangular shaped cool area in the centre bottom where the sludge is.

If the trapped gas is air rather than hydrogen, then the cause is
likely to be different - typically air being sucked into the system
through the system vent. This is generally caused by the pipework
not being organised correctly or the pump setting being too high.
It should also be fixed, because if air is pulled into the system,
apart from being annoying, it does promote corrosion.


Scottish Gas came to fix and told me that
the build up of air was actually gas which was coming from various nasty
stuff inside the heaters and provided me with a hefty quote to flush out my
heating system.

Well, what a surprise!. I bet the quote was several hundred pounds,
right? The typical offering is power flushing which involves
circulating a chemical cleaner under pressure around the system.
The margin is outrageous as you probably guessed. BG are notorious
for this. If you do decide to go for this route, shop around for a
fair price.

I had a colleague who was taken for about £800 for this job for about
8 radiators in a flat. The job was bungled and the problem, which
turned out to be something totally different, was not fixed. My
colleague refused to pay and the contractor threatened legal action in
the Small Claims Division of the court. His bluff was called and
the case was dropped. The contractor saddled up and rode into the
sunset.

My question is this: can this be done diy (husband is
quite good at it) and if so what does he need in the way of equipment and
chemicals etc.

There are various things that you can do on a DIY basis.

The first thing is to identify how bad the problem is. The easy way
to do that is check for sludging as described and look for evidence of
poor heating of radiators.

You can also drain the system and remove a radiator to check. Look
for sludge in the radiator. A word of warning. Sludge from
corrosion in a CH system, and the water is a superb indellible brown
dye. If there is a lot of sludge, then power flushing may well
make sense, because there is probably also a lot of build up in the
pipes as well. You can hire the equipment and buy the chemical at
hire centres. Instructions are supplied, and it is a very easy job
to do.

Another approach if there is not too much sludge is to remove each
radiator and clean it by flushing outside with a hose or pressure
washer. You can flush water through the system at each radiator
valve to clear silt from the pipework, again if the build up is not
excessive.

If the system is relatively clean, and in any case after the last
method, you can flush the system and drain it and then refill with a
flushing agent (Fernox and Sentinel among others make these). These
are left in the system for a week while it is run hot and then drained
and flushed.

Finally, in all cases, refill and add inhibitor.





Thanks in advance

Margaret


..andy

To email, substitute .nospam with .gl

"David W.E. Roberts" wrote in
:

There should be at least one central heating FAQ floating
about. Try http://www.diyfaq.org.uk/ for starters.
No doubt the plumbing pros will point you to more resources.
HTH
Dave R

I was going to refer to the faqs, David, but there appears to be nothing on
this item there;

chance for someone to get famous? I would, but my knowledge is pretty
d-i-y, (IYSWIM)

mike r

Andy Hall wrote:
On Sun, 31 Aug 2003 19:16:23 +0100, "Margaret Macfarlane"
wrote:
Snipped

Scottish Gas came to fix and told me that
the build up of air was actually gas which was coming from various
nasty stuff inside the heaters and provided me with a hefty quote to
flush out my heating system.

Well, what a surprise!. I bet the quote was several hundred pounds,
right? The typical offering is power flushing which involves
circulating a chemical cleaner under pressure around the system.
The margin is outrageous as you probably guessed. BG are notorious
for this. If you do decide to go for this route, shop around for a
fair price.

I had a colleague who was taken for about £800 for this job for about
8 radiators in a flat. The job was bungled and the problem, which
turned out to be something totally different, was not fixed. My
colleague refused to pay and the contractor threatened legal action in
the Small Claims Division of the court. His bluff was called and
the case was dropped. The contractor saddled up and rode into the
sunset.

Andy,

My experience was a lot different to this with British Gas. I had them
power flush an 8 rad system for £460 and yes, I did have problems (mostly
noise) caused by the flush which were all resolved by BG in the original
quote e.g.

A new heat exchanger in the boiler.
Re-worked pipework in the airing cupboard.
A new C/H pump.
A second power flush because there was still muck in the system from a
dip in a pipe in an inaccessible part of the system.

There were still minor problems 12 months after which were picked up on the
annual boiler service and BG returned and fixed these FOC.

Oh! and three months after the original works were completed and the bill
paid, BG sent me a cheque for over thirty pounds as a rebate because they
over quoted the original job as they had not deducted a discount because of
my maintenance contract with them.

As an extra issue to this, under the British Gas warranty of these works,
provided I allow them to inspect and replenish the inhibitors (I pay for the
inhibitors) every two years, they will re-power flush for free if needed in
the future (very likely in my ageing system).

Snipped.



Brian

On Sun, 31 Aug 2003 21:08:21 +0100, Andy Hall
wrote:

Sludge from
corrosion in a CH system, and the water is a superb indellible brown
dye

Although if you're trying to get this out of floorboards, whilst
sanding them, then oxalic acid is a useful bleach.

On Sun, 31 Aug 2003 22:04:09 +0000 (UTC), "Brian"
wrote:



Andy,

My experience was a lot different to this with British Gas. I had them
power flush an 8 rad system for £460 and yes, I did have problems (mostly
noise) caused by the flush which were all resolved by BG in the original
quote

I am pleased that you are happy, but you are paying a lot of money for
this.

Do you realise that you can hire a power flushing machine for £36 for
half a day or £42 for a full day? You can *buy* the machine for
£900.


e.g.

A new heat exchanger in the boiler.
Re-worked pipework in the airing cupboard.
A new C/H pump.
A second power flush because there was still muck in the system from a
dip in a pipe in an inaccessible part of the system.

They would have had to replace the heat exchanger and the pump as part
of the maintenance contract anyway. That is costing £140/annum
IIRC, and in most years you would be getting a service with a cost
value of no more than £50. With this over several years and the
margin on the power flush there is plenty in hand to cover these
eventualities



There were still minor problems 12 months after which were picked up on the
annual boiler service and BG returned and fixed these FOC.

Oh! and three months after the original works were completed and the bill
paid, BG sent me a cheque for over thirty pounds as a rebate because they
over quoted the original job as they had not deducted a discount because of
my maintenance contract with them.

As an extra issue to this, under the British Gas warranty of these works,
provided I allow them to inspect and replenish the inhibitors (I pay for the
inhibitors) every two years, they will re-power flush for free if needed in
the future (very likely in my ageing system).


If you were taking care of the system yourself, you would typically
part drain and add inhibitor every 2-3 years anyway.

To be honest, if the system is clean and maintained in this way, it is
very unlikely that it would need power flushing.
I used inhibitor in my system from new and maintained it religiously.
During a refurbishment a year ago (when the system was 17 years old,
there was virtually no build up of sludge (just small amounts in the
bottom of a couple of radiators) and flushing produced a little
copper swarf that was the original from when the system was installed.
Almost all the radiaotors have been retained, with a few being sized
upwards to allow lower operating temperature with a condensing boiler.

I'm pleased that your experience has been good in the sense that the
system is in good order (now) and you are pleased. However, it is
very much akin to domestic appliance insurance. You pay a lot of
money for it.

I used to have a BG annual cover policy. However, I had occasion to
use it when the thermocouple on my old boiler failed and prevented it
from firing (as it should). I called BG early in the morning
expecting that they would attend either the same day or at the latest,
the following day. I was asked whether I had anybody "at risk",
meaning small children or the elderly in the house. I didn't but
pointed out that I did have a contract. The earliest that they
could manage was five days later.

I cancelled the contract and after a lot of hassle, obtained a full
refund. They still appear to be operating with the old monopoly
attitude that they are doing one a favour to even show up. If they
were operating on a limited public budget then prioritising the
vulnerable might be reasonable. When they are operating on a
commercial basis and charging an arm and a leg for a contract, it is
not.

I replaced the thermocouple for a cost of £3 in parts from the local
plumber's merchant.

I have an open case with the ASA about BG's advertising of these
contracts, especially the "paramedics" add with the "experienced
fitter" and the dopey boy. They are creating the illusion with this
that they are providing an emergency service when they are not.
It's almost as though Alastair Campbell wrote the copy.
The advert is completely dishonest in the impression that it gives
the customer.

As I say, if you are happy with what you are getting and paying then
that's fine. However, the "peace of mind" may not be what you think
and is not coming cheaply. In a year or two you will "need" a new
boiler. When you receive BG's quote, make some comparisons with
local firms and I think you will be shocked.


..andy

To email, substitute .nospam with .gl

Several experts have replied, but I havent seen any of them say
that if the system is open vented, you need to check for over-
pumping. (see the FAQ). I bet Scot. gas didnt check either.

Good luck

Andy Hall wrote:
On Sun, 31 Aug 2003 22:04:09 +0000 (UTC), "Brian"
wrote:



Andy,

Snipped

I am pleased that you are happy, but you are paying a lot of money for
this.

Do you realise that you can hire a power flushing machine for £36 for
half a day or £42 for a full day? You can *buy* the machine for
£900.

Andy, After being "in the trade" so to speak since 1965 both as a tradesman
and a general foreman I understand the costings very well and whilst not
adverse to "having a go" I learnt a very long time ago that perhaps
sometimes you pay "for the knowledge" rather than the actual work as this
can save a large amount of cash in the long run - look at the number of
requests for help in this group as a result of a lack of knowledge.

e.g.

A new heat exchanger in the boiler.
Re-worked pipework in the airing cupboard.
A new C/H pump.
A second power flush because there was still muck in the system
from a dip in a pipe in an inaccessible part of the system.

They would have had to replace the heat exchanger and the pump as part
of the maintenance contract anyway. That is costing £140/annum
IIRC, and in most years you would be getting a service with a cost
value of no more than £50. With this over several years and the
margin on the power flush there is plenty in hand to cover these
eventualities

In this instance Andy no - it was the flushing chemicals that caused the
problems with the heat exchanger and the pump was noisy and part of the
original contract.

With regards to the maintenance contract - over the years I have use their
services on average of perhaps four to five times a year with about half of
those times requiring spares - I estimate that I have broken even on the
contract subscription and certainly paid less than calling out a private
contractor.


Snipped

If you were taking care of the system yourself, you would typically
part drain and add inhibitor every 2-3 years anyway.

To be honest, if the system is clean and maintained in this way, it is
very unlikely that it would need power flushing.
I used inhibitor in my system from new and maintained it religiously.
During a refurbishment a year ago (when the system was 17 years old,
there was virtually no build up of sludge (just small amounts in the
bottom of a couple of radiators) and flushing produced a little
copper swarf that was the original from when the system was installed.
Almost all the radiaotors have been retained, with a few being sized
upwards to allow lower operating temperature with a condensing boiler.

Andy, after my years as foreman on housing maintenance, which included
heating repairs on solid fuel, electric and gas and seeing the results of
some of the amateur work (and near fatalities due to carbon monoxide
poisoning) I'm afraid that as I do not have the technical qualifications or
the detailed knowledge, I prefer in this case to let the professionals do
the work. Hence the reason I do not advise in this group on either gas or
electrical queries even though I have a general knowledge of both and
capable of doing the work.


I'm pleased that your experience has been good in the sense that the
system is in good order (now) and you are pleased. However, it is
very much akin to domestic appliance insurance. You pay a lot of
money for it.

On domestic appliance insurance I quite agree - it's money for all rope and
I refuse to pay for it as most repairs are minor anyway.


I used to have a BG annual cover policy. However, I had occasion to
use it when the thermocouple on my old boiler failed and prevented it
from firing (as it should). I called BG early in the morning
expecting that they would attend either the same day or at the latest,
the following day. I was asked whether I had anybody "at risk",
meaning small children or the elderly in the house. I didn't but
pointed out that I did have a contract. The earliest that they
could manage was five days later.

I have been asked the same questions and I have had to wait - BUT as I can
determine as whether the repair is urgent or not and I have separate forms
of heating and hot water it has never been a problem. When I have told them
that the works are urgent, described thy symtoms and the asked the
telephonist to get an engineer to ring me when THEY have been unsure all my
urgent stuff has been done the same day.


I cancelled the contract and after a lot of hassle, obtained a full
refund. They still appear to be operating with the old monopoly
attitude that they are doing one a favour to even show up. If they
were operating on a limited public budget then prioritising the
vulnerable might be reasonable. When they are operating on a
commercial basis and charging an arm and a leg for a contract, it is
not.

I have never had this attitude to be fair.


I replaced the thermocouple for a cost of £3 in parts from the local
plumber's merchant.

I have an open case with the ASA about BG's advertising of these
contracts, especially the "paramedics" add with the "experienced
fitter" and the dopey boy. They are creating the illusion with this
that they are providing an emergency service when they are not.
It's almost as though Alastair Campbell wrote the copy.
The advert is completely dishonest in the impression that it gives
the customer.

Again when I have had a "true" emergency they have always responded very
quickly to do the emergency repair to make safe etc but I have to wait some
lengthy periods for spares for my out of date boiler a few years ago.

As I say, if you are happy with what you are getting and paying then
that's fine. However, the "peace of mind" may not be what you think
and is not coming cheaply. In a year or two you will "need" a new
boiler. When you receive BG's quote, make some comparisons with
local firms and I think you will be shocked.

Changed my boiler about eight years ago Andy when my old and very outdated
Pottertern Neataheat finally broke down and spares were unabtainable (just
before Christmas as luck would have it).
The cost of supplying and fitting my new boiler £800 and half a day to fit
it and because the design of my heating system is rather "cranky" to say the
least - (and that is another saga is it was fitted when the house was new
and a long time before my occupation) - another half a day to get the water
flowing and the electrics working - plus new thermostatic valves supplied
and fitted for free in all my bedrooms.

With regards to quotes from other sources, yes I have done that and I also
know various qualified, corgi registered plumbers who could "do it on the
cheap" but I have found with British Gas in my area of South East Wales,
that when I get a quote off them it is never the cheapest but the do the job
for that price whatever the complications and the NEVER quibble or argue
about their warranty work.

And yes I do bitch about the cost with their reps call and haggle like hell
to get the price down or freebies :-)

Brian

Brian wrote:

With regards to the maintenance contract - over the years I have use their
services on average of perhaps four to five times a year with about half of
those times requiring spares - I estimate that I have broken even on the
contract subscription and certainly paid less than calling out a private
contractor.

What kind of system do you have that it needs 4-5 callouts a
year?? I would seriously consider a complete replacement. I
would not be prepared to live with a CH/HW system that required
that much attention.

In our last house, we had conventional gas CH/HW. In all the
time we were there, I cleaned out the boiler every couple of
years, checked the CO at the same time, and added inhibitor.
That was about it. The only things it ever needed was a new
thermocouple and a replacement pump.

In our current house I installed our oil system just under 2
years ago, and haven't touched it since.

To me, that's how they should behave.

--
Grunff

On Mon, 1 Sep 2003 13:19:23 +0000 (UTC), "Brian"
wrote:



They would have had to replace the heat exchanger and the pump as part
of the maintenance contract anyway. That is costing £140/annum
IIRC, and in most years you would be getting a service with a cost
value of no more than £50. With this over several years and the
margin on the power flush there is plenty in hand to cover these
eventualities

In this instance Andy no - it was the flushing chemicals that caused the
problems with the heat exchanger and the pump was noisy and part of the
original contract.

Didn't that strike you as somewhat incompetent? They should be using
the correct materials fo rthe job.



With regards to the maintenance contract - over the years I have use their
services on average of perhaps four to five times a year with about half of
those times requiring spares - I estimate that I have broken even on the
contract subscription and certainly paid less than calling out a private
contractor.


I'm sure you're right regarding costs on this basis, but there is
something seriously wrong with a system that breaks down every 3
months. Again, I would be suspicious that BG are not doing a proper
job.





Andy, after my years as foreman on housing maintenance, which included
heating repairs on solid fuel, electric and gas and seeing the results of
some of the amateur work (and near fatalities due to carbon monoxide
poisoning) I'm afraid that as I do not have the technical qualifications or
the detailed knowledge, I prefer in this case to let the professionals do
the work. Hence the reason I do not advise in this group on either gas or
electrical queries even though I have a general knowledge of both and
capable of doing the work.

That's fine and the main point of DIY is knowing when not to do so.

However, you can shop around for services. I would have thought that
your experience would tell you when you have somebody competent and
are getting a good deal. Your heating system experience sounds like
neither to me.





I used to have a BG annual cover policy. However, I had occasion to
use it when the thermocouple on my old boiler failed and prevented it
from firing (as it should). I called BG early in the morning
expecting that they would attend either the same day or at the latest,
the following day. I was asked whether I had anybody "at risk",
meaning small children or the elderly in the house. I didn't but
pointed out that I did have a contract. The earliest that they
could manage was five days later.

I have been asked the same questions and I have had to wait - BUT as I can
determine as whether the repair is urgent or not and I have separate forms
of heating and hot water it has never been a problem. When I have told them
that the works are urgent, described thy symtoms and the asked the
telephonist to get an engineer to ring me when THEY have been unsure all my
urgent stuff has been done the same day.

That is the whole problem with all of this - people accepting poor
performance. Their contract should specify a maximum response time
and there should be cash compensation for failure to meet that. It
is how services should be provided by a professional organisation,
which leads me to believe that either BG don't understnad this or that
they do and are understaffing in order to make more money.
Both are totally unacceptable.

I also have backups for both heating and hot water, but that is not
the point. If I pay for a contract that they market as being an
emergency service, that is what they should provide, not something
based on degree of apparent social need.



As I say, if you are happy with what you are getting and paying then
that's fine. However, the "peace of mind" may not be what you think
and is not coming cheaply. In a year or two you will "need" a new
boiler. When you receive BG's quote, make some comparisons with
local firms and I think you will be shocked.

Changed my boiler about eight years ago Andy when my old and very outdated
Pottertern Neataheat finally broke down and spares were unabtainable (just
before Christmas as luck would have it).
The cost of supplying and fitting my new boiler £800 and half a day to fit
it and because the design of my heating system is rather "cranky" to say the
least - (and that is another saga is it was fitted when the house was new
and a long time before my occupation) - another half a day to get the water
flowing and the electrics working - plus new thermostatic valves supplied
and fitted for free in all my bedrooms.

With regards to quotes from other sources, yes I have done that and I also
know various qualified, corgi registered plumbers who could "do it on the
cheap" but I have found with British Gas in my area of South East Wales,
that when I get a quote off them it is never the cheapest but the do the job
for that price whatever the complications and the NEVER quibble or argue
about their warranty work.

That's easy to do when you sandbag the price :-)


..andy

To email, substitute .nospam with .gl

"mike ring" wrote in message
52.50...
"Margaret Macfarlane" wrote in
:

Hi,

Just found this newsgroup and discovered that there are more than
14,000 headers to download so forgive me if this question has already
been asked

Where have you been?

Scottish
Gas came to fix and told me that the build up of air was actually gas
which was coming from various nasty stuff inside the heaters and
provided me with a hefty quote to flush out my heating system.

They would, just like here
My question is this: can this be done diy (husband is quite good at it)
and if so what does he need in the way of equipment and chemicals etc.

Unless your problems are really dire, and they don't sound it,

drain a bit and add Fernox Superfloc (or one of the competitors ie
screwfix 16307)

Run the system for a few days

Drain and refill several times to flush out.

Fill up againn with additional Fernox MB-1 (or a competitor ie screwfix
13162)

Thats it

HTH

Mike R


Why is the Fernox so much more expensive (5x) than the other?

Pete

"PM" wrote in
:



Why is the Fernox so much more expensive (5x) than the other?

Pete


I'm not really sure - Fernox comes in 4 litre size, and screwfix in 1
litre, but screwfix is alleged to treat up to 10 rads.

IIRC, Fernox at 4% will do my system twice , so there's a saving there.

I don't know about qjality - I have to assume they bothe work as
advertised, so that makes the screwfix one a better buy

mike r

"M. Damerell" wrote in
:


Several experts have replied, but I havent seen any of them say
that if the system is open vented, you need to check for over-
pumping. (see the FAQ).

To quote Andy Hall, yesterday, in this thread

"If the trapped gas is air rather than hydrogen, then the cause is
likely to be different - typically air being sucked into the system
through the system vent. This is generally caused by the pipework
not being organised correctly or the pump setting being too high.
It should also be fixed, because if air is pulled into the system,
apart from being annoying, it does promote corrosion."

mike r

On Mon, 1 Sep 2003 17:24:06 +0100, "PM"
wrote:




Why is the Fernox so much more expensive (5x) than the other?

Pete


I can give you two reasons.

1) Fernox products have been on the market for donkey's years (at
least 25) and the results are well known and demonstrated.
The Screwfix product may well be the same stuff but is an unknown.

Having used the Fernox stuff for over 25 years I *know* it works.

In the context of a heating system costing typically £5k on a
commercial basis, £20 is neither here nor there.

2) Why does a dog lick its parts?




..andy

To email, substitute .nospam with .gl

"mike ring" wrote in message
52.50...
"PM" wrote in
:



Why is the Fernox so much more expensive (5x) than the other?

Pete


I'm not really sure - Fernox comes in 4 litre size, and screwfix in 1
litre, but screwfix is alleged to treat up to 10 rads.

IIRC, Fernox at 4% will do my system twice , so there's a saving there.

I don't know about qjality - I have to assume they bothe work as
advertised, so that makes the screwfix one a better buy

mike r

I'll give the Screwfix one a go I think...

Pete

"Andy Hall" wrote in message
...
On Tue, 2 Sep 2003 08:45:41 +0100, "PM"
wrote:


"Andy Hall" wrote in message
.. .
On Mon, 1 Sep 2003 17:24:06 +0100, "PM"
wrote:




Why is the Fernox so much more expensive (5x) than the other?

Pete


I can give you two reasons.

1) Fernox products have been on the market for donkey's years (at
least 25) and the results are well known and demonstrated.
The Screwfix product may well be the same stuff but is an unknown.

Having used the Fernox stuff for over 25 years I *know* it works.

In the context of a heating system costing typically £5k on a
commercial basis, £20 is neither here nor there.



True, but if the cheaper stuff does exactly the same job I'd rather pay
£3.50 than £20


Ah, but you won't know for three or four years and by that time it
might be Too Late (to quote Milne).

I think it might already be too late - I've got no idea how much inhibitor
is in the system, I suspect very little and one rad has already rusted
through from the inside.



2) Why does a dog lick its parts?


Just cos they can doesn't mean I have to like it :-)

I don't think I'll write the comment that just occurred to me......

LOL

Pete

(A colleague of mine actually said "LOL" to me once!)

RichardS wrote:
"Andy Hall" wrote in message
...
On Sun, 31 Aug 2003 19:16:23 +0100, "Margaret Macfarlane"
wrote:

Hi,

Just found this newsgroup and discovered that there are more than
14,000 headers to download so forgive me if this question has
already been asked
[Snip]

The build up may well be hydrogen gas, rather than air. Hydrogen
is the product of corrosion of metal components in the system. In
addition to the pump, you would expect to find it gathering in the
tops of radiators. You can easily test whether it is hydrogen by
opening a radiator vent and applying a match or other flame.
Hydrogen burns with a pale blue flame.

snip

This is the only part of the advice that I'd disagree with.

When testing for hydrogen I would never advise applying the flame
directly to the vent, but rather collecting in an upturned container,
then introducing a (long) match or splint to the container (still
upturned). A satisfying "pop" should be heard if hydrogen is present.

cheers
Richard
I'd advise caution here too. Heard of a guy who applied match as he opened
rad air bleed valve.
It was combustible gas and the resultant large flame startled him and caused
a large burn mark on his wall.

"Grunff" wrote in message
...
Brian wrote:

With regards to the maintenance contract - over the years I have use
their
services on average of perhaps four to five times a year with about half
of
those times requiring spares - I estimate that I have broken even on the
contract subscription and certainly paid less than calling out a private
contractor.

What kind of system do you have that it needs 4-5 callouts a
year?? I would seriously consider a complete replacement. I
would not be prepared to live with a CH/HW system that required
that much attention.

Hi Grunff,

Sorry for the delay in replying but my VIA motherboard suddenly took a
dislike to my Alcatel modem and the thing had to be changed (motherboard
that is)

Back to the subject. It was a Potterton Neataheat wall mounted, balanced
flue boiler that was rather old and tired and the pipeworks AND electrics
were designed and installed in a new house (the whole site was the same)
literally the "wrong way around" thus causing a great many problems - hence
the 3 star British Gas maintenance contract - no other firm could sort out
the mess.

In our last house, we had conventional gas CH/HW. In all the
time we were there, I cleaned out the boiler every couple of
years, checked the CO at the same time, and added inhibitor.
That was about it. The only things it ever needed was a new
thermocouple and a replacement pump.

The Potterton was a nightmare for BG to maintain, at its peak they would be
attending at least once a month for a huge variety of problems and it
finally gave up the ghost when the cast iron flue rusted away and there were
no spares available. A new Baxi Wall mounted boiler cut the call outs down
for a few years - but even this has a problem with condensation on the
electrode which prevents it igniting now and again - and BG gets the call to
fix it.


In our current house I installed our oil system just under 2
years ago, and haven't touched it since.

To me, that's how they should behave.

I quite agree but unfortunately, short of a totally new installation and the
mess and upset it causes, I am stuck with what I have got. When I had
fairly major problems with silt in the pipes getting BG to flush it out was
a damn site cheaper than replacing the system.

Brian