Hi All,

Wonder if anyone can shed any light on an issue with my boiler/heating
system.

We recently removed a bathroom radiator temprarily while retiling. After it
had been replaced we bled the radiators etc. The pressure had dropped at
this point to zero bar on the boiler, so we topped it up via the tap to 1
bar.

Now when the heating is on, the pressure guage on the front of the boiler
climbs rapidly from 1 bar to almost off the scale within around 30 mins (I
have turned it off before it actually goes off the scale in case it is
dangerous).

Any ideas on why this may be happening or should I call an engineer out?

Best wishes, thanks in advance, R

r wrote:
Hi All,

Wonder if anyone can shed any light on an issue with my boiler/heating
system.

We recently removed a bathroom radiator temprarily while retiling. After it
had been replaced we bled the radiators etc. The pressure had dropped at
this point to zero bar on the boiler, so we topped it up via the tap to 1
bar.

Now when the heating is on, the pressure guage on the front of the boiler
climbs rapidly from 1 bar to almost off the scale within around 30 mins (I
have turned it off before it actually goes off the scale in case it is
dangerous).

Any ideas on why this may be happening or should I call an engineer out?

Best wishes, thanks in advance, R



I know sod all about heating but I did have a similar problem to you. I
had to bleed the rads a few times over a week or so before the guage
settled down. Then I had to remove half a litre or so via a bleed valve
to get it down to normal. The guage on my 24i is certainly very
sensitive given the amount of water in the system as a whole. You
wouldn't think a pint would make much difference one way or the other

r wrote:

We recently removed a bathroom radiator temprarily while retiling. After it
had been replaced we bled the radiators etc. The pressure had dropped at
this point to zero bar on the boiler, so we topped it up via the tap to 1
bar.

Now when the heating is on, the pressure guage on the front of the boiler
climbs rapidly from 1 bar to almost off the scale within around 30 mins (I
have turned it off before it actually goes off the scale in case it is
dangerous).

I'd say you've got an airlock in the system and it needs to be
forced/bled out. I doubt all your radiators are hot, right?

David

Update! Thanks for the comments so far folks.

As I said, we'd set the pressure to 1 bar at about 6pm - system left off and
when I checked at 9.30ish it's down to half a bar with no human
intervention!

I popped the heating on and it's up to 3 bar within 15 minutes!

I've put it off again but a quick check of the rads and they all seem hot.

Very odd.

R

"Lobster" wrote in message
...
r wrote:

We recently removed a bathroom radiator temprarily while retiling. After
it had been replaced we bled the radiators etc. The pressure had dropped
at this point to zero bar on the boiler, so we topped it up via the tap
to 1 bar.

Now when the heating is on, the pressure guage on the front of the boiler
climbs rapidly from 1 bar to almost off the scale within around 30 mins
(I have turned it off before it actually goes off the scale in case it is
dangerous).

I'd say you've got an airlock in the system and it needs to be forced/bled
out. I doubt all your radiators are hot, right?

David

"r" wrote in message
...
Hi All,

Wonder if anyone can shed any light on an issue with my boiler/heating
system.

We recently removed a bathroom radiator temprarily while retiling. After
it had been replaced we bled the radiators etc. The pressure had dropped
at this point to zero bar on the boiler, so we topped it up via the tap to
1 bar.

Now when the heating is on, the pressure guage on the front of the boiler
climbs rapidly from 1 bar to almost off the scale within around 30 mins (I
have turned it off before it actually goes off the scale in case it is
dangerous).

Any ideas on why this may be happening or should I call an engineer out?

Best wishes, thanks in advance, R



Rapidly increasing pressure like this suggests a failed expansion vessel,
not a need to bleed.

A need to bleed would cause the system to have higher compressibility ( gas
volume ), which would cause the pressure to increase less for a given
temperature increase. That is not what you are seeing. You are seeing
the opposite.

Like I say, looks like your expansion chamber is empty or goosed.

--
Ron

On Sat, 19 Apr 2008 23:17:15 +0100, me9 wrote:

On 19 Apr,
"r" wrote:

Update! Thanks for the comments so far folks.

As I said, we'd set the pressure to 1 bar at about 6pm - system left
off and when I checked at 9.30ish it's down to half a bar with no
human intervention!

I popped the heating on and it's up to 3 bar within 15 minutes!

I've put it off again but a quick check of the rads and they all seem
hot.

Very odd.

Sounds as if the pressure vessel has lost it's pre-charge. See the
sealed system FAQ. It may be possible to re-charge via a tyre pump.

http://www.makewrite.demon.co.uk/SealedCH.html


It seems to be down at the moment Ed?

Checked as working at 22:10 on 21/4/8.
Demon are a fairly reliable and probably better than most ISP.


--
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