Microbore Heating Systems
Frank Price
Can anyone advise me on draining my microbore central heating system? I need
to drain it, flush it out and treat it with sludge and corrosion inhibitors
(Fernox).
I live in a four bedroomed house with with 14 radiators (7 upstairs; 7
downstairs)
Due to noisy breakdown of the pump I had to replace it this last week - and
found it almost "chocker-block" with oxide deposits. The new pump is now
showing early signs of making the same sort of unhealthy noises that the old
one was before I replaced it.
The radiators are all entry one side / exit the other (not the combined at
one end type) and the lockshield valves on the downstairs radiators all have
what looks like a hose connector opposite the radiator connector. Is this a
drain valve perchance?
I imagine I have to drain all the downstairs radiators individually -
through these valves(?).
Ed Sirett
Frank Price wrote in message ...
>Help!!!
>Can anyone advise me on draining my microbore central heating system? I
need
>to drain it, flush it out and treat it with sludge and corrosion inhibitors
>(Fernox).
>
>I live in a four bedroomed house with with 14 radiators (7 upstairs; 7
>downstairs)
>
>Due to noisy breakdown of the pump I had to replace it this last week - and
>found it almost "chocker-block" with oxide deposits. The new pump is now
>showing early signs of making the same sort of unhealthy noises that the
old
>one was before I replaced it.
>
>The radiators are all entry one side / exit the other (not the combined at
>one end type) and the lockshield valves on the downstairs radiators all
have
>what looks like a hose connector opposite the radiator connector. Is this a
>drain valve perchance?
>
I fear I have nothing but bad news to give you.
It is really important that a microbore system is as sludge free as possible
and to keep it that may.
You are going to have to drain down, remove each rad cleaning out with a
hose, and then flush the whole system with an de-sludger (that gets the rest
of the sludge into suspension), and finally fill and add inhibitor.
Given that _each_ radiator has a drain point downstairs, I suspect that all
the downstairs rads are fed from above, (concrete downstairs floor eh?).
That would account for the large number of drain points.
HTH sorry to be the bearer of such bad news
Ed Sirett
Property Maintainer - North London.
Dave Liquorice
> The new pump is now showing early signs of making the same sort of
> unhealthy noises that the old one was before I replaced it.
Did you bleed it? Most if not all circulators use the water as a bearing
lubricant and motor coolant (if water at 80+C can be considered a coolant!)
I stick my hand up and admit I failed to do this when I replaced the pump in
Bristol a few years back. It lasted just over a year before failing, it's
replacement was bled and is still going strong several years later as it
should be.
--
Cheers new...@nexus.demon.co.uk
Dave. Remove "spam" for valid email.
John
Frank Price <frank...@pionexnet.co.uk> wrote in message
news:IVby4.4995$7F3.1...@nnrp4.clara.net...
> Help!!!
> Can anyone advise me on draining my microbore central heating system? I
need
> to drain it, flush it out and treat it with sludge and corrosion
inhibitors
> (Fernox).
>
> I live in a four bedroomed house with with 14 radiators (7 upstairs; 7
> downstairs)
>
> Due to noisy breakdown of the pump I had to replace it this last week -
and
> showing early signs of making the same sort of unhealthy noises that the
old
> one was before I replaced it.
Assuming you did bleed the air out of it as per instructions I'd be wary of
some of the crud you found being loose in the system and has been moved
into the new pump. Depending on the severity of the coating you will
probably need to do a chemical clean with Fernox DS40 Acid cleanser. Beware
its aggressive stuff and you must read and observe all the instructions
with it.
>
> The radiators are all entry one side / exit the other (not the combined
at
> one end type) and the lockshield valves on the downstairs radiators all
have
> what looks like a hose connector opposite the radiator connector. Is this
a
> drain valve perchance?
Could well be there is one type of rad valve tail with a removable drain
plug in a branch. You turn off both sides of the rad, remove plug, fit
hose, open valve(s), drain. Or you fit hose and open air vent to drain
just the radiator for removal.
>
After the chemical clean its best to remove each rad and take it outside
for a flush out with a hose.
BTW is your pump pushing to the system or pulling water back from the rads?
If its pulling back (Pumped return) this is often the cause of air
entrainment and causes the kind of problems you describe.
Mungo Henning
Frank Price wrote:
> I imagine I have to drain all the downstairs radiators individually -
> through these valves(?).
Methinks common practise is to hide away somewhere a "sludge valve".
Look around the perimeter of your house for a single pipe poking out at
ground level. Lift floorboards and ascertain whether it has a valve connected
to it and it is part of the heating system pipework.
Close the valve to the (assumed) header tank, open this valve and
all the water will drain outside.
YMMV
Mungo
--
Mungo Henning - it's a daft name but it goes with the face...
mun...@bigfoot.com http://www.itacs.strath.ac.uk/
I speak for me, not my employer.
Frank Price
BTW is your pump pushing to the system or pulling water back from the rads?
If its pulling back (Pumped return) this is often the cause of air
entrainment and causes the kind of problems you describe.
Thank you all for your valuable advice.
John -
The pump is pushing to the system, straight from the header tank in the
loft immediately above the airing cupboard (where the pump is situated).
I did bleed the pump when I first refilled it after fitting and also bled
the first radiator (the one which usually suffers from backfeed).
I am afraid it is going to be a bit bigger job than I had hoped - still, it
will keep me out of mischief, won't it?
Kindest regards, and thank you again,
Frank Price