I need to fit a new radiator into my bathroom. My CH system is a 20
year old gas boiler a HW tank and cold water tank in the loft. I was
expecting to find a central heating cold water tank but I dont have
one.

Where does the water for my radiators come from and how is it heated.

I want to work out what I have to do to drain my radiators to fit the
new one.

Could the radiators just use DHW? Will my HW tank have a seperate
circuit for heating the radiators?

On Wed, 9 Jan 2008 04:23:19 -0800 (PST), 405 TD Estate
wrote:

|I need to fit a new radiator into my bathroom. My CH system is a 20
|year old gas boiler a HW tank and cold water tank in the loft. I was
|expecting to find a central heating cold water tank but I dont have
|one.

Your system could easily use the existing CW tank for both CH and
HW. It could even use the same outlet pipe and split further
down. Trace the pipe.

|Where does the water for my radiators come from and how is it heated.
|
|I want to work out what I have to do to drain my radiators to fit the
|new one.
|
|Could the radiators just use DHW? Will my HW tank have a seperate
|circuit for heating the radiators?

Probably a standard indirect system. How many pipes are connected
to your HW tank?

On Jan 9, 12:23*pm, 405 TD Estate wrote:
I need to fit a new radiator into my bathroom. My CH system is a 20
year old gas boiler a HW tank and cold water tank in the loft. I was
expecting to find a central heating cold water tank but I dont have
one.


Are you *sure* the HW tank is in the loft? It's not normally located
there.

adder1969 wrote:
On Jan 9, 12:23 pm, 405 TD Estate wrote:
I need to fit a new radiator into my bathroom. My CH system is a 20
year old gas boiler a HW tank and cold water tank in the loft. I was
expecting to find a central heating cold water tank but I dont have
one.


Are you *sure* the HW tank is in the loft? It's not normally located
there.

Maybe there should be commas after "boiler" and the first "tank".
--
LSR

On Jan 9, 1:08*pm, adder1969 wrote:
On Jan 9, 12:23*pm, 405 TD Estate wrote:

I need to fit a new radiator into my bathroom. My CH system is a 20
year old gas boiler a HW tank and cold water tank in the loft. I was
expecting to find a central heating cold water tank but I dont have
one.

Are you *sure* the HW tank is in the loft? *It's not normally located
there.

Are *you* sure it's in the loft? Are you *sure* the OP said it was?

MBQ

On Jan 9, 1:38*pm, "Man at B&Q" wrote:
On Jan 9, 1:08*pm, adder1969 wrote:

On Jan 9, 12:23*pm, 405 TD Estate wrote:

I need to fit a new radiator into my bathroom. My CH system is a 20
year old gas boiler a HW tank and cold water tank in the loft. I was
expecting to find a central heating cold water tank but I dont have
one.

Are you *sure* the HW tank is in the loft? *It's not normally located
there.

Are *you* sure it's in the loft? Are you *sure* the OP said it was?

MBQ

No, reading it again I'm not! I think there needs to be more than
commas :-) From the posting I thought maybe he was confusing the CH
header with the HW tank :-)

Sorry the HW tank/cylinder is on the 1st (bedroom) floor, boiler is
on the ground floor and there is a water tank in the loft which
refills when hot water has been used.

So where do the radiators get their water from - how do I drain and
refill them?

On Jan 9, 4:32*pm, 405 TD Estate wrote:
Sorry the HW tank/cylinder *is on the 1st (bedroom) floor, boiler is
on the ground floor and there is a water tank in the loft which
refills when hot water has been used.

So where do the radiators get their water from - how do I drain and
refill them?

It's not a sealed system is it? I guess you have to try to figure out
for yourself.

In an earlier contribution to this discussion,
405 TD Estate wrote:

Sorry the HW tank/cylinder is on the 1st (bedroom) floor, boiler is
on the ground floor and there is a water tank in the loft which
refills when hot water has been used.

So where do the radiators get their water from - how do I drain and
refill them?

It seems to me that there are three possibilities:

1. There *is* a fill & expansion tank in the loft, but you haven't yet
located it.

2. You have a sealed/pressurised system - in which case there will be an
expansion vessel and filling loop somewhere.

3. You have a Primatic HW cylinder (a work of the devil!) which includes an
internal partial interconnection of the primary and secondary circuits, such
that they share a single header tank, and therefore cannot use inhibitor in
the CH system.

Sounds like a bit more investigation is required in order to determine
exactly what you've got. How long have you lived in the house?
--
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 Wed, 9 Jan 2008 04:23:19 -0800 (PST), 405 TD Estate
wrote:

I need to fit a new radiator into my bathroom. My CH system is a 20
year old gas boiler a HW tank and cold water tank in the loft. I was
expecting to find a central heating cold water tank but I dont have
one.

Where does the water for my radiators come from and how is it heated.

I want to work out what I have to do to drain my radiators to fit the
new one.

Could the radiators just use DHW? Will my HW tank have a seperate
circuit for heating the radiators?


It could possibly be a Primatic system. Both the hot water and heating
circuit are fed from the same tank. The water going into the storage
cylinder feeds both during initial fill up but then an airlock is
formed that keeps the two circuits seperate. We had one that worked
fine until the inlet bush started to leak.

There is a good illustration of one here


http://salamander-engineering.co.uk/...re/faq/faq.htm

On 10 Jan, 17:37, wrote:
On 9 Jan, *
* * *John Evans wrote:

It could possibly be a Primatic system. Both the hot water and heating
circuit are fed from the same tank. The water going into the storage
cylinder feeds both during initial fill up but then an airlock is
formed that keeps the two circuits seperate. We had one that worked
fine until the inlet bush started to leak.

I would expect anyone with a primatic system over 20 years old to have had
problems by now. They were never very successful at isolating
primary/secondary water, as they could lose the bubble of air if the water
got too hot.


I converted mine to a sealed system in the end, bypassing the filling
from the HWC and fitting an expansion vessel and filling loop
instead. It's still going as far as I'm aware. Rads were never any
problem. It was a mains fed one though, not from an expansion tank.

My boiler certainly has the same connections as the Primatic one i.e.
two at the botton one either side, one halfway up and 1 at the top -
would any other boilers have a connection 1/2 way up?

There could be a small expansion tank hidden in insulation towards the
edges of the roof but I didn't notice one when i bourded the loft outh
though I did not do all the way to the edges.