On Wed, 04 Jan 2006 23:38:57 -0800, Mike wrote:

Hello,

I am looking for a little bit of advice on my central heating system. I
have just bought a small 2 bedroom terraced house and have been given a
bit of doom and gloom by British Gas (I know maybe not the most popular
people on here but I am a total novice when it comes to central heating
and hot water supplies as this is my first house.

The system is approximately 10 years old running off an Ideal Elan
NF230 boiler supplying a Thermal Storage Cylinder (set at 75c). It's
got a small copper header/expansion tank above the cylinder with a
copper lid, 2 pumps, and a Room Thermostat/programmer in the lounge.

I have done a bit of digging around on these and if I understand it
correctly, the boiler heats the water in cylinder which is used to feed
the radiators, the 2 pumps are connected one to the boiler feed and one
to the radiator feed. The HW is then fed at mains pressure through a
heat exchanger/coil inside the tank to heat and passed to the outlets.

Sounds like the Gledhill Boilermate thermal store system I came across in
a flat the other day.

The central heating system is all non-barrier plastic pipe and of
course is original with the house except for pipe work around the
cylinder which appears to be copper, according to the British Gas
engineer the plastic pipe (and a few pages I have looked at on the
internet) is a very bad thing[tm].

He basically said that the system is a poor design, with a low powered
boiler (which is probably fair point, the maximum flow seems to be 80c
where as the tank wants to be 75c so there is not much redundancy
there). So its running at full kilt. He said the plastic pipe will
allow lots of oxygen in the system to corrode the radiators (I have had
2 off with the help of my dad and they were full of black cr*p but none
seem to be holed).

As Ed has said you don't need a huge boiler to heat the flat so that
won't be a problem. As for the non-barrier pipe even BG are (officially)
happy with this provided corrosion inhibitor is used in the system, as it
inevitably is these days.


He said what I will find is that my HW is not great when the heating is
running because the water from the cylinder is being cycled to the rads
which makes sense. I have not moved in yet, as I am decorating the
place first. He also said its very prone to limescale (we do live in a
hard water area).

You probably should have a scale inhibitor on the cold feed to the system
in that case. As for HW performance, when the flat is heating up from
freezing cold the HW delivery may be less but it should still be vastly
better than a combi could provide.


They did agree to look after my boiler and system on HomeCare 200 but
obviously had a good winge about how poor the system is and that I
should think about a PowerFlush (which I can ill afford to be quite
honest). He admitted I was getting circulation in the CH and so there
was no blockage, and it should be working so agreed to cover it. He
even went to far as to say that he would not have bought the house
purely because of the central heating :O I was a bit taken aback by
that, surely its not that bad?

Hmmn, British Gas slagging off a system and suggesting expensive
'remedial' work. Well, knock me down with a feather. :-)


So without changing the whole system, pipework etc etc I am planing to
do the following;

Drain the system fully down and flush out the radiators as much as I
can by running water through them. They all heat up well except the big
rad in the lounge which has a cold spot at the bottom (which I suspect
is full of crap).

Then use Purimachos Flushex to see if I can clean the system further,
before adding some Purimachos Protex Inhibitor to a fresh filled
system.

Dunno about Flushex but my own test suggests that Protex doesn't
work whereas Fernox MB-1 and Sentinel X100 do.
http://82.24.138.95/~john/Inhibitor/index.html
If you want to economise you're probably as well peeing in the water
(I'll test that next time :-)


What do people think? Should I really think about replacing the system
if it's working? As I have said I have not moved in yet so not
spending a lot of time there so the system is on low. I suppose until I
move in I wont see how good the CH and HW supply is although I suspect
as a single bloke living there alone its going to be adequate.

More than adequate ...