Best Central Heating Inhibitor / Anti-freeze

[.mother]

I usually use basic antifreeze in boat central heating systems and
generally this has always proved alright. It's recently occurred to
me that this doesn't have any inhibitor though[1], and as I'm about to
start changing radiators, thought I'd ask for recs on an additive
that'll not only 'not freeze', but also protect the new shiny rads and
Alde boiler :-)


[1] I noted this whilst draining the system and also looking at what
was in the expansion tank in the Aldi!

[Bob Fleming]

Post by .mother
I usually use basic antifreeze in boat central heating systems and
generally this has always proved alright. It's recently occurred to
me that this doesn't have any inhibitor though[1], and as I'm about to
start changing radiators, thought I'd ask for recs on an additive
that'll not only 'not freeze', but also protect the new shiny rads and
Alde boiler :-)
[1] I noted this whilst draining the system and also looking at what
was in the expansion tank in the Aldi!

Learn from my mistake - a really stupid one in hindsight, but I thought I
was doing the right thing at the time being new to boating and boat systems.

Boat fitted with Webasto Thermotop C diesel boiler supplying calorifier and
cabin radiators. Boat was "pre-loved" by somebody else, so I decided to
change all fluids for fresh ones when I took it over. I thought about the
central heating system and decided to protect the radiators with the same
stuff I used at home, Fernox. It may well have protected the boat radiators
but it rotted out the boiler waterjacket in the alloy body of the Webasto -
doh! Not meant for use with such materials. After expensive rebuild now use
50/50 mix with good quality automotive antifreeze and it has worked a treat
for the last three years. A good heater that saw me through two winters
onboard.

Bob.

[John Gwalter]

Post by Bob Fleming

Post by .mother
I usually use basic antifreeze in boat central heating systems and
generally this has always proved alright. It's recently occurred to
me that this doesn't have any inhibitor though[1], and as I'm about to
start changing radiators, thought I'd ask for recs on an additive
that'll not only 'not freeze', but also protect the new shiny rads and
Alde boiler :-)
[1] I noted this whilst draining the system and also looking at what
was in the expansion tank in the Aldi!

Learn from my mistake - a really stupid one in hindsight, but I thought I
was doing the right thing at the time being new to boating and boat systems.
Boat fitted with Webasto Thermotop C diesel boiler supplying calorifier
and cabin radiators. Boat was "pre-loved" by somebody else, so I decided
to change all fluids for fresh ones when I took it over. I thought about
the central heating system and decided to protect the radiators with the
same stuff I used at home, Fernox. It may well have protected the boat
radiators but it rotted out the boiler waterjacket in the alloy body of
the Webasto - doh! Not meant for use with such materials. After expensive
rebuild now use 50/50 mix with good quality automotive antifreeze and it
has worked a treat for the last three years. A good heater that saw me
through two winters onboard.
Bob.

All diesel boilers used in boats are derived from truck heaters and as such
designed to work with automotive antifreezes.
I have to use this in mine as it uses a common circuit with the engine
cooling system, allowing the engine to heat the radiators when moving.
I know some of the books say it can't be done but I have got away with it.

[Tony Haynes]

On Nov 24, 10:41 pm, "Bob Fleming"
<***@ntlworld.com> wrote:
I thought about the

Post by Bob Fleming
central heating system and decided to protect the radiators with the same
stuff I used at home, Fernox. It may well have protected the boat radiators
but it rotted out the boiler waterjacket in the alloy body of the Webasto -
doh!

Fernox is bad news even in domestic plumbing. It is supposed to stop
scaling and corrosion in rads, but in my experience it does more harm
than good. I have had brand new radiators pin-holed and boiler jackets
holed after use of Fernox (to protect the system!) even after correct
flushing and mixing on a brand newly installed system. Trying to get a
claim was a nightmare. Fernox blamed the rad manufacturer, and the rad
manufacturer blamed Fernox until they both decided that I had the mix
wrong... which I didn't. Don't use it.

Tone

[.mother]

Post by .mother
It's recently occurred to
me that this doesn't have any inhibitor

Which apparently is WRONG!

Spoke to Richard at Alde who confirmed that what I'm using already is
quite alright as most good anti-freeze these days already contains an
inhibitor. Always nice to find out what one is already doing is
right, for a change :-)

[r***@yahoo.co.uk]

Post by .mother
Which apparently is WRONG!
Spoke to Richard at Alde who confirmed that what I'm using already is
quite alright as most good anti-freeze these days already contains an
inhibitor.  Always nice to find out what one is already doing is
right, for a change :-)

As you have already found out antifreeze DOES have corrosion
inhibitors in it, and it is designed for use in mixed metal systems,
cast iron engine block and aluminium cylinder head for example. The
reason that you change antifreeze in a car cooling system every two to
five years (depending on the spec of the anitfreeze originally fitted)
is to renew the anti-corrosion inhibitors. The anti-freeze constituent
lasts nearly indefinitely but the anti-corrosion inhibitors don't. So,
if you treat your heating system with a mix of between 30% and 50%,
and renew every 2 to 3 years (with your average commonly available
antifreeze) you will be safe and corrosion inhibited. If you need to
top the system up remember to use a matching mix of antifreeze to
water so that you don't slowly dilute your protection.
Roger
nb ex-motortrade