hi,

i've looked on line for help with this but i'm struggling to come up
with a complete answer. i have a back boiler behind the fire not sure
what model but its way over 20 years old. hot water cylinder in airing
cupboard upstairs that can be heated by gas or elec , one tank in loft.
think looking at diagrams an indirect water cylinder

last night while heating and hot water was on tank sounded as though it
was bubbling. turned the bolier off checked elec switch hadn't been
turned on by accident (it hadn't ), tank still sounded as though it
was bubbling so i opened the tap on the bath the water colour was fine
and clear but scalding hot.

then there was some almight rumbling as though the house was coming
down so i opened the tap on the bath bit more and then the water in the
bath from the hot tap started to turn black smiliar to water in heating
system. the rumbling contiued the whole time the water was running so i
turned off the water to the tank and let the taps run dry the bottom
of the bath was really black and gritty.

my guess is new cylinder as water heater coil in tank gone???

anyone have a rough guide how much this going to cost me???

any advise welcome

thanks in advance

melanie

On 23 Apr 2006 16:48:24 -0700, wrote:

hi,

i've looked on line for help with this but i'm struggling to come up
with a complete answer. i have a back boiler behind the fire not sure
what model but its way over 20 years old. hot water cylinder in airing
cupboard upstairs that can be heated by gas or elec , one tank in loft.
think looking at diagrams an indirect water cylinder

last night while heating and hot water was on tank sounded as though it
was bubbling. turned the bolier off checked elec switch hadn't been
turned on by accident (it hadn't ), tank still sounded as though it
was bubbling so i opened the tap on the bath the water colour was fine
and clear but scalding hot.

then there was some almight rumbling as though the house was coming
down so i opened the tap on the bath bit more and then the water in the
bath from the hot tap started to turn black smiliar to water in heating
system. the rumbling contiued the whole time the water was running so i
turned off the water to the tank and let the taps run dry the bottom
of the bath was really black and gritty.

my guess is new cylinder as water heater coil in tank gone???

anyone have a rough guide how much this going to cost me???

If it's a cylinder replacement only, then the price range is likely to
be in the low £hundreds - i.e. in the £200-500 range depending on the
work involved.

However, if the black water is, indeed from the boiler primary side it
is indicative of corrosion going on in the heating system so it would
be prudent for the boiler and radiators to be checked and the primary
side to be cleaned out and corrosion inhibitor added. In any case
the boiler should be checked and serviced if not done recently, so
perhaps another £100-200 for this part assuming that nothing bad has
happened to boiler and radiators are OK.




any advise welcome

thanks in advance

melanie

--

..andy

In an earlier contribution to this discussion,
Andy Hall wrote:


my guess is new cylinder as water heater coil in tank gone???

anyone have a rough guide how much this going to cost me???

If it's a cylinder replacement only, then the price range is likely to
be in the low £hundreds - i.e. in the £200-500 range depending on the
work involved.

If there is *really* only one tank in the attic, could it be a primatic
cylinder (although I thought these usually have intergral header tanks)?

If it *is* a primatic cylinder, it sounds as if something has happened to
make the primary and secondary circuits mix in a big way. I don't know
enough about them to know whether this is fixable without replacing the
whole thing. Inhibitor wouldn't be an option.

If it *is* a primatic, and *does* need replacing, it would be a good idea to
replace it with a standard indirect cylinder with separate header and F&E
tanks so as to separate the primary and secondary circuits completely - and
*then* to use inhibitor.
--
Cheers,
Roger
______
Email address maintained for newsgroup use only, and not regularly
monitored.. Messages sent to it may not be read for several weeks.
PLEASE REPLY TO NEWSGROUP!

On Mon, 24 Apr 2006 10:08:09 +0100, Roger Mills wrote:

In an earlier contribution to this discussion,
Andy Hall wrote:


my guess is new cylinder as water heater coil in tank gone???

anyone have a rough guide how much this going to cost me???

If it's a cylinder replacement only, then the price range is likely to
be in the low £hundreds - i.e. in the £200-500 range depending on the
work involved.

If there is *really* only one tank in the attic, could it be a primatic
cylinder (although I thought these usually have intergral header tanks)?

If it *is* a primatic cylinder, it sounds as if something has happened to
make the primary and secondary circuits mix in a big way. I don't know
enough about them to know whether this is fixable without replacing the
whole thing. Inhibitor wouldn't be an option.

If it *is* a primatic, and *does* need replacing, it would be a good idea to
replace it with a standard indirect cylinder with separate header and F&E
tanks so as to separate the primary and secondary circuits completely - and
*then* to use inhibitor.

Agreed.
I would add that unless the OP is totally skint the entire system is up
for a total overhaul.


--
Ed Sirett - Property maintainer and registered gas fitter.
The FAQ for uk.diy is at http://www.diyfaq.org.uk
Gas fitting FAQ http://www.makewrite.demon.co.uk/GasFitting.html
Sealed CH FAQ http://www.makewrite.demon.co.uk/SealedCH.html
Choosing a Boiler FAQ http://www.makewrite.demon.co.uk/BoilerChoice.html

wrote:
hi,

i've looked on line for help with this but i'm struggling to come up
with a complete answer. i have a back boiler behind the fire not sure
what model but its way over 20 years old. hot water cylinder in airing
cupboard upstairs that can be heated by gas or elec , one tank in loft.
think looking at diagrams an indirect water cylinder

last night while heating and hot water was on tank sounded as though it
was bubbling. turned the bolier off checked elec switch hadn't been
turned on by accident (it hadn't ), tank still sounded as though it
was bubbling so i opened the tap on the bath the water colour was fine
and clear but scalding hot.

then there was some almight rumbling as though the house was coming
down so i opened the tap on the bath bit more and then the water in the
bath from the hot tap started to turn black smiliar to water in heating
system. the rumbling contiued the whole time the water was running so i
turned off the water to the tank and let the taps run dry the bottom
of the bath was really black and gritty.

my guess is new cylinder as water heater coil in tank gone???

anyone have a rough guide how much this going to cost me???

any advise welcome

thanks in advance

melanie

is there a thermostat on the cylinder,

if no could it be the boiler overheat senseor has failed and system
expanded into the hot water header?

if so then maybe if you post the boiler details someone may give you a
rough price for replacement or direct you to a stockist if it is
replaceable!

On Mon, 24 Apr 2006 21:37:32 +0100, Ed Sirett
wrote:

On Mon, 24 Apr 2006 10:08:09 +0100, Roger Mills wrote:

In an earlier contribution to this discussion,
Andy Hall wrote:


my guess is new cylinder as water heater coil in tank gone???

anyone have a rough guide how much this going to cost me???

If it's a cylinder replacement only, then the price range is likely to
be in the low £hundreds - i.e. in the £200-500 range depending on the
work involved.

If there is *really* only one tank in the attic, could it be a primatic
cylinder (although I thought these usually have intergral header tanks)?

If it *is* a primatic cylinder, it sounds as if something has happened to
make the primary and secondary circuits mix in a big way. I don't know
enough about them to know whether this is fixable without replacing the
whole thing. Inhibitor wouldn't be an option.

If it *is* a primatic, and *does* need replacing, it would be a good idea to
replace it with a standard indirect cylinder with separate header and F&E
tanks so as to separate the primary and secondary circuits completely - and
*then* to use inhibitor.

Agreed.
I would add that unless the OP is totally skint the entire system is up
for a total overhaul.

I concur - although a total overhaul may not be necessary.

It's very likely to be a primatic cylinder. These rely on a kind of
air bubble to separate the hot water/heating water. It is possible
for the air bubble to collapse, which allows the circuits to mix.
This may be your problem. Just drain down the entire system and
refill first - this could fix the issue.

See http://www.plumbingpages.com/feature...HWprimatic.cfm for more
info on Primatic tanks.

If you have any spare cash though I would suggest that you replace the
cylinder as Ed suggested. Primatic cylinders preclude the option to
use inhibitor and are inefficient.

Good Luck,
Mark

thanks for all your help, the back boiler is an ideal cavalcade and we
have been advised most likely its a problem with thermostat on that.?
as we've been putting off getting new boiler for the last couple of
years and are hoping to let our property next year. we're thinking
this might be ideal time to do it as it needs fixing anyway.

thank you to everyone who replied it was a great help