Hello,

I have moved into a house with an unknown CH history. The cylinder may
be 30 years old like the house, then again, it may have been fitted
the day before I moved in. It is a very hard water area.

I see you can buy fernox ds3 to descale potable hot water. Is it worth
trying some of this? Or is it a case of "if it's not broke, don't fix
it"?

I have not looked inside the cylinder to see if scale is a problem for
two reasons: removing the immersion heater would require emptying the
cylinder and that seems a waste of hot water. Secondly, I think I read
here that if you remove immersion heaters they can be a pig to fit
back and if you cross thread them, you need to buy a new cylinder:
ouch!

Is it worth a bit of preventive maintenance with DS3? If so, will the
small 250g (?) B&Q pots be enough or do I need a trade 2kg tub?

Thanks,
Stephen.

In article ,
Stephen writes:
Hello,

I have moved into a house with an unknown CH history. The cylinder may
be 30 years old like the house, then again, it may have been fitted
the day before I moved in. It is a very hard water area.

I see you can buy fernox ds3 to descale potable hot water. Is it worth
trying some of this? Or is it a case of "if it's not broke, don't fix
it"?

I have not looked inside the cylinder to see if scale is a problem for
two reasons: removing the immersion heater would require emptying the
cylinder and that seems a waste of hot water. Secondly, I think I read
here that if you remove immersion heaters they can be a pig to fit
back and if you cross thread them, you need to buy a new cylinder:
ouch!

Is it worth a bit of preventive maintenance with DS3? If so, will the
small 250g (?) B&Q pots be enough or do I need a trade 2kg tub?

I use DS-3 for descaling various things from time to time,
but I've never put it inside the house pipework. It takes
lots of rinsing to get rid of it, and you'd probably end
up flushing through many tank fulls to get it out of your
hot water cylinder. It has a dye so you can see it's there
and tell when it's spent (it's an indicator which changes
colour from yellow to green), and it has a smell added,
again so you can tell it's present.

I buy 2kg tubs because it works out much cheaper, although
in the last few years, no one seems to stock it anymore so
you have to go to mail order, or get a wholesaler to order
you in a tub. Actually, I just bought 3 x 2kg tubs from BES
(only one for me -- some collegues also wanted some having
seen me use it). Those 2kg tubs are probably the cheapest
way to buy Sulphamic Acid.

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

In article ,
Stephen wrote:
I have moved into a house with an unknown CH history. The cylinder may
be 30 years old like the house, then again, it may have been fitted
the day before I moved in. It is a very hard water area.

I see you can buy fernox ds3 to descale potable hot water. Is it worth
trying some of this? Or is it a case of "if it's not broke, don't fix
it"?

Well I live in London where the water's pretty hard and my cylinder is 30
years old and never had the potable side descaled. Still works fine.

Is there a reason why you want to?

--
*Nostalgia isn't what is used to be.

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

On Fri, 16 Jan 2009 12:19:13 +0000, Stephen wrote:

I have not looked inside the cylinder to see if scale is a problem for
two reasons: removing the immersion heater would require emptying the
cylinder and that seems a waste of hot water.

Turn off the cold supply to tank and drain down to below the level of the
immersion boss, if that's on the dome it's not very much water.

Secondly, I think I read here that if you remove immersion heaters they
can be a pig to fit back and if you cross thread them, you need to buy a
new cylinder:

They can be pigs to get out. IIRC the best tool to use is an immersion
socket spanner rather than a ring spanner, crack the joint before you
drain as the water, in theory, provides a bit of support for the cylinder.
Clean all the threads and mating surfaces before replacing and use
plumbers mait and a bit of care and cross threading shouldn't be a
problem.

Personally I wouldn't bother with either the descaling (yuk, descaler in
your DHW supply) or looking. Unless the reheat time is very long, by that
I mean 1hr from incoming mains temperature cold.

--
Cheers
Dave.

On Fri, 16 Jan 2009 14:23:26 +0000 (GMT), "Dave Liquorice"
wrote:

Turn off the cold supply to tank and drain down to below the level of the
immersion boss, if that's on the dome it's not very much water.

Unfortunately, rather than have one big immersion heater going down
from the top, my cylinder has two smaller immersion heaters: one near
the bottom and one higher up. To check the bottom one would require
draining most of the water. OTOH as the other poster said, I would
have to drain it to flush it out afterwards, so I guess draining can't
be avoided.

They can be pigs to get out. IIRC the best tool to use is an immersion
socket spanner rather than a ring spanner, crack the joint before you
drain as the water, in theory, provides a bit of support for the cylinder.
Clean all the threads and mating surfaces before replacing and use
plumbers mait and a bit of care and cross threading shouldn't be a
problem.

I guess the ring type of spanners are no use now that cylinders come
sprayed thick with foam.

Can you use plumber's mait on immersion bosses? I thought it was for
dirty water joints?

Personally I wouldn't bother with either the descaling (yuk, descaler in
your DHW supply) or looking. Unless the reheat time is very long, by that
I mean 1hr from incoming mains temperature cold.

Do you mean reheat by immersion heater or reheat by boiler? We do use
economy 7 with the immersion heaters so I have no idea whether it
takes seven minutes or seven hours. I will have to try to reheat
during the day when I am awake to monitor it.

Thanks.

On Fri, 16 Jan 2009 21:52:11 +0000, Stephen wrote:

Unfortunately, rather than have one big immersion heater going down
from the top, my cylinder has two smaller immersion heaters: one near
the bottom and one higher up. To check the bottom one would require
draining most of the water.

No just take drain enough to remove the top one and use a torch and small
mirror. I guess these two go into the sides as an E7 setup.

Do you mean reheat by immersion heater or reheat by boiler?

I was thinking via a boiler as E7 had not been mentioned before. Nothing
like leaving pertinant facts out to get duff answers in return.

We do use economy 7 with the immersion heaters so I have no idea whether
it takes seven minutes or seven hours. I will have to try to reheat
during the day when I am awake to monitor it.

Not sure how you'll tell then unless there is some indication when the
stats in the immersions have opened. Which isn't usual. Running water out
to see how hot it slows down the reheat as you are introducing more
cold...

--
Cheers
Dave.

"Stephen" wrote in message
...
Hello,



I would not try to remove an immersion heater that is working as you risk
damaging the tank during the removal. I would suggest living with whatever
scale has built up.



--
Michael Chare

In article ,
Stephen wrote:
Turn off the cold supply to tank and drain down to below the level of
the immersion boss, if that's on the dome it's not very much water.

Unfortunately, rather than have one big immersion heater going down
from the top, my cylinder has two smaller immersion heaters: one near
the bottom and one higher up. To check the bottom one would require
draining most of the water. OTOH as the other poster said, I would
have to drain it to flush it out afterwards, so I guess draining can't
be avoided.

Surely you could just add it via the header tank if you must - drain it
down first to avoid too much dilution. You don't drink water from that -
so flushing should be just as effective - or not - for both hot and cold.

--
*Why isn't there mouse-flavoured cat food?

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