I have a Baxi Bermuda 552 back boiler which gives pumped central heating and
(what I believe is termed) gravity hot water, ie, when system is set to hot
water only, the upstairs rads get warm as well.

I drained the system down today to replace a radiator (pipework needs
altering) and I'm going to take the opportunity to also put in sludge and
gunk remover, flush and finally add inhibitor. I went into the loft to tie
up the ball valve then drained the system from the lowest drain cock (which
took about 4 hours, even opening the bleed valves on the upstairs rads when
the water level ahd dropped enough).

Thing is, we now have no water coming out of the hot tap. I knew we wouldn't
have _hot_ water because there isn't any heating to heat it but I still
expected water to come from the hot tap. My missus has had the washing
machine on almost all day so that may well account for it, but that leads me
to the conclusion that the tank in the loft where I tied up the ball valve,
also feeds the domestic hot water system. Is this correct?

My original plan was (when I'm ready) to pour the sludge remover (and later
the inhibitor) into the tank in the loft but if it does, indeed, also feed
the domestic hot water then I guess that's a no-no, so just how do you get
it in there?

Cheers,

Mogweed.

On Mon, 28 Feb 2005 00:12:09 -0000, "Mogweed" strung
together this:

My original plan was (when I'm ready) to pour the sludge remover (and later
the inhibitor) into the tank in the loft but if it does, indeed, also feed
the domestic hot water then I guess that's a no-no, so just how do you get
it in there?

Just to clarify, you tied up the ball valve on the small tank only?
You should have 2 tanks, a big one for the hot water and a small one
for the heating. If this isn't the case, then we need to find out what
you have got.
--

SJW
Please reply to group or use 'usenet' in email subject

Mogweed wrote:
I have a Baxi Bermuda 552 back boiler which gives pumped central
heating and
(what I believe is termed) gravity hot water, ie, when system is set
to hot
water only, the upstairs rads get warm as well.

no, thats called a plumbing ---up. Your upstairs rads are on the hot
water circuit.


I drained the system down today to replace a radiator

I'm guessing you replaced one of the ones on the HW circuit.


(pipework needs
altering) and I'm going to take the opportunity to also put in sludge
and
gunk remover, flush and finally add inhibitor. I went into the loft
to tie
up the ball valve then drained the system from the lowest drain cock
(which
took about 4 hours, even opening the bleed valves on the upstairs
rads when
the water level ahd dropped enough).

Thing is, we now have no water coming out of the hot tap. I knew we
wouldn't
have _hot_ water because there isn't any heating to heat it but I
still
expected water to come from the hot tap. My missus has had the
washing
machine on almost all day so that may well account for it, but that
leads me
to the conclusion that the tank in the loft where I tied up the ball
valve,
also feeds the domestic hot water system. Is this correct?

yep


My original plan was (when I'm ready) to pour the sludge remover (and
later
the inhibitor) into the tank in the loft but if it does, indeed, also
feed
the domestic hot water then I guess that's a no-no, so just how do
you get
it in there?

dont do that!!

1. By putting the chemicals in the right tank
2. It might also help to put your upstairs rads on the CH circuit
instead of the HW one. More economical and sanitary. But while its on
HW, dont even think of putting chemicals in it.

If in confusion, it may help to put a bottle of food dye into each
header tank and see what comes out where.


NT

wrote in message
oups.com...
Mogweed wrote:
I have a Baxi Bermuda 552 back boiler which gives pumped central
heating and
(what I believe is termed) gravity hot water, ie, when system is set
to hot
water only, the upstairs rads get warm as well.

no, thats called a plumbing ---up. Your upstairs rads are on the hot
water circuit.


I drained the system down today to replace a radiator

I'm guessing you replaced one of the ones on the HW circuit.


(pipework needs
altering) and I'm going to take the opportunity to also put in sludge
and
gunk remover, flush and finally add inhibitor. I went into the loft
to tie
up the ball valve then drained the system from the lowest drain cock
(which
took about 4 hours, even opening the bleed valves on the upstairs
rads when
the water level ahd dropped enough).

Thing is, we now have no water coming out of the hot tap. I knew we
wouldn't
have _hot_ water because there isn't any heating to heat it but I
still
expected water to come from the hot tap. My missus has had the
washing
machine on almost all day so that may well account for it, but that
leads me
to the conclusion that the tank in the loft where I tied up the ball
valve,
also feeds the domestic hot water system. Is this correct?

yep


My original plan was (when I'm ready) to pour the sludge remover (and
later
the inhibitor) into the tank in the loft but if it does, indeed, also
feed
the domestic hot water then I guess that's a no-no, so just how do
you get
it in there?

dont do that!!

1. By putting the chemicals in the right tank
2. It might also help to put your upstairs rads on the CH circuit
instead of the HW one. More economical and sanitary. But while its on
HW, dont even think of putting chemicals in it.

If in confusion, it may help to put a bottle of food dye into each
header tank and see what comes out where.


NT


Thanks Lurch and NT. There's only one tank in the loft so I guess it's the
"worst case scenario" time eh? (

Mogweed.

The message .com
from contains these words:

Mogweed wrote:
I have a Baxi Bermuda 552 back boiler which gives pumped central
heating and
(what I believe is termed) gravity hot water, ie, when system is set
to hot
water only, the upstairs rads get warm as well.

no, thats called a plumbing ---up. Your upstairs rads are on the hot
water circuit.

More likely that the upstairs rads are getting gravity circulation when
the pump is off.

--
Roger

Roger wrote:
The message .com
from contains these words:
Mogweed wrote:

I have a Baxi Bermuda 552 back boiler which gives pumped central
heating and
(what I believe is termed) gravity hot water, ie, when system is
set
to hot
water only, the upstairs rads get warm as well.

no, thats called a plumbing ---up. Your upstairs rads are on the
hot
water circuit.

More likely that the upstairs rads are getting gravity circulation
when
the pump is off.

Spose it depends how hot they get with HW on and CH off. But whatever
the deal I'd suggest some food dye for the OP, to ensure you dont put
nasties in your water supply.

NT

On Mon, 28 Feb 2005 00:12:09 -0000, "Mogweed" wrote:

I have a Baxi Bermuda 552 back boiler which gives pumped central heating and
(what I believe is termed) gravity hot water, ie, when system is set to hot
water only, the upstairs rads get warm as well.

I drained the system down today to replace a radiator (pipework needs
altering) and I'm going to take the opportunity to also put in sludge and
gunk remover, flush and finally add inhibitor. I went into the loft to tie
up the ball valve then drained the system from the lowest drain cock (which
took about 4 hours, even opening the bleed valves on the upstairs rads when
the water level ahd dropped enough).

Thing is, we now have no water coming out of the hot tap. I knew we wouldn't
have _hot_ water because there isn't any heating to heat it but I still
expected water to come from the hot tap. My missus has had the washing
machine on almost all day so that may well account for it, but that leads me
to the conclusion that the tank in the loft where I tied up the ball valve,
also feeds the domestic hot water system. Is this correct?

My original plan was (when I'm ready) to pour the sludge remover (and later
the inhibitor) into the tank in the loft but if it does, indeed, also feed
the domestic hot water then I guess that's a no-no, so just how do you get
it in there?

Do you actually have one or two header tanks in the loft? If you just
have one large tank you may have a Primatic cylinder and you cannot
use inhibitor in case your DHW gets contaminated.

Mark

On Mon, 28 Feb 2005 16:25:02 +0000, Mark
wrote:

snip
My original plan was (when I'm ready) to pour the sludge remover (and later
the inhibitor) into the tank in the loft but if it does, indeed, also feed
the domestic hot water then I guess that's a no-no, so just how do you get
it in there?

Do you actually have one or two header tanks in the loft? If you just
have one large tank you may have a Primatic cylinder and you cannot
use inhibitor in case your DHW gets contaminated.

Mark

This is close to my own problem, so I thought I'd ask here.

I have a single tank in the roof. The central heating pump has two
automatic valves below it - one controls the ch and the other is on a
pipe to the hot water cylinder. The whole thing is powered by a
Potterton wall mounted gas boiler.

The central heating alone works fine - all radiators get hot. But the
hot water, when set on the same twice-a-day timer as the central
heating, boils. Atleast, I think it's boiling - there's a sudden rush
of air - pretty alarming - from the cylinder, which then vents into
the roof tank.

Where does the air come from and how can I stop it?

On Tue, 01 Mar 2005 13:01:47 +0000, Pete
wrote:

On Mon, 28 Feb 2005 16:25:02 +0000, Mark
wrote:

snip
Do you actually have one or two header tanks in the loft? If you just
have one large tank you may have a Primatic cylinder and you cannot
use inhibitor in case your DHW gets contaminated.

Mark

This is close to my own problem, so I thought I'd ask here.

I have a single tank in the roof. The central heating pump has two
automatic valves below it - one controls the ch and the other is on a
pipe to the hot water cylinder. The whole thing is powered by a
Potterton wall mounted gas boiler.

The central heating alone works fine - all radiators get hot. But the
hot water, when set on the same twice-a-day timer as the central
heating, boils. Atleast, I think it's boiling - there's a sudden rush
of air - pretty alarming - from the cylinder, which then vents into
the roof tank.

Where does the air come from and how can I stop it?

I'm not an expert but did once have a Primatic cylinder. The only
ways I know of to reduce the termperature of the hot water with these
systems is to only have your central heating/hot water on for short
periods (so that the tank does not have time to heat up too much) or
to reduce the boiler thermostat temperature.

The latter, of course, will make your central heating water colder,
but may not be a problem.

When I had a Primatic cylinder I had to keep adjusting the boiler
thermostat. For the first hour of central heating have it on high to
heat the house. After that I turned the boiler stat down to prevent
the hot water overheating. In the summer it's not a problem - you can
just keep the stat on low.

Hope this helps.
Mark