Hi folks.
We've got this new "lodge" on a park in Cheddar which has an on-going
list of faults etc. prior to being let out. At the moment my biggest
issue is the heating (or lack thereof) which has had various leaks and
things but my current concern is as to whether the boiler has been
commissioned correctly.

System wise there are 5 small radiators and 2 large towel radiators.
it's 2 beds, 2 bathrooms and a hall/kitchen/diner

The radiators are all plumbed up in plastic microbore (which appears to
be causing most of the problems with pathetically unstable connections
going pushfit on pipe to screw connection on TRV body.

The boiler is a Worcester whatever of which there is no external
expansion vessel so I'm guessing a small internal one exists.
Firstly, should this be pressurised by the commissioning plumber or
would/should it be pre pressurised? That said, if it's been pressurised
correctly should such a relatively small CH system expect to increase
pressure by around 0.5 bar from cold to working temp. or would this
point to the expansion vessel having not been pressurised?

Doesn't seem right to me but at home I have a pretty big external
expansion vessel and the pressure only changes by 1 or 2 psi at the most
with significantly greater water volume.

Cheers
Pete

On 22/12/2014 16:57, www.GymRatZ.co.uk wrote:
Hi folks.
We've got this new "lodge" on a park in Cheddar which has an on-going
list of faults etc. prior to being let out. At the moment my biggest
issue is the heating (or lack thereof) which has had various leaks and
things but my current concern is as to whether the boiler has been
commissioned correctly.

System wise there are 5 small radiators and 2 large towel radiators.
it's 2 beds, 2 bathrooms and a hall/kitchen/diner

The radiators are all plumbed up in plastic microbore (which appears to
be causing most of the problems with pathetically unstable connections
going pushfit on pipe to screw connection on TRV body.

The boiler is a Worcester whatever of which there is no external
expansion vessel so I'm guessing a small internal one exists.
Firstly, should this be pressurised by the commissioning plumber or
would/should it be pre pressurised? That said, if it's been pressurised
correctly should such a relatively small CH system expect to increase
pressure by around 0.5 bar from cold to working temp. or would this
point to the expansion vessel having not been pressurised?

Doesn't seem right to me but at home I have a pretty big external
expansion vessel and the pressure only changes by 1 or 2 psi at the most
with significantly greater water volume.

Cheers
Pete


I would expect it to have been pre-pressurised. A rise of 0.5 bar from
cold to hot is perfectly reasonable. A rise of only 1 or 2 PSI is
distinctly odd!
--
Cheers,
Roger
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In article ,
"www.GymRatZ.co.uk" writes:
Hi folks.
We've got this new "lodge" on a park in Cheddar which has an on-going
list of faults etc. prior to being let out. At the moment my biggest
issue is the heating (or lack thereof) which has had various leaks and
things but my current concern is as to whether the boiler has been
commissioned correctly.

System wise there are 5 small radiators and 2 large towel radiators.
it's 2 beds, 2 bathrooms and a hall/kitchen/diner

The radiators are all plumbed up in plastic microbore (which appears to
be causing most of the problems with pathetically unstable connections
going pushfit on pipe to screw connection on TRV body.

Unfortunately, cheap and quick to install is about all one can say
about such an installation.

The boiler is a Worcester whatever of which there is no external
expansion vessel so I'm guessing a small internal one exists.
Firstly, should this be pressurised by the commissioning plumber or
would/should it be pre pressurised? That said, if it's been pressurised

IME, they come pressurised.

correctly should such a relatively small CH system expect to increase
pressure by around 0.5 bar from cold to working temp. or would this
point to the expansion vessel having not been pressurised?

Sounds about right.
Normally a heating system will raise in pressure by 1 - 2 bar, depending
how big it is and what the cold to hot temperature differencial is.
Yous is a small system, so it raises less than normal, but that's not
a problem.

Doesn't seem right to me but at home I have a pretty big external
expansion vessel and the pressure only changes by 1 or 2 psi at the most
with significantly greater water volume.

Sounds strange. Are you sure that's not bar, rather than PSI?

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

On 22/12/2014 16:57, www.GymRatZ.co.uk wrote:

The boiler is a Worcester whatever of which there is no external
expansion vessel so I'm guessing a small internal one exists.

Almost certainly... (assuming its a sealed system boiler)

Firstly, should this be pressurised by the commissioning plumber or
would/should it be pre pressurised? That said, if it's been pressurised

It comes pre pressurised.

correctly should such a relatively small CH system expect to increase
pressure by around 0.5 bar from cold to working temp. or would this
point to the expansion vessel having not been pressurised?

0.5 bar is a relatively low rise in pressure, but plausible for a small
volume system.

Doesn't seem right to me but at home I have a pretty big external
expansion vessel and the pressure only changes by 1 or 2 psi at the most
with significantly greater water volume.

In which case I would be worried about the home system ;-)

(are you sure its not changing by 1 or 2 bar rather than PSI)?


--
Cheers,

John.

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On 22/12/2014 17:28, Andrew Gabriel wrote:

Doesn't seem right to me but at home I have a pretty big external
expansion vessel and the pressure only changes by 1 or 2 psi at the most
with significantly greater water volume.

Sounds strange. Are you sure that's not bar, rather than PSI?

Haven't actually measured the difference in PSI but the pressure gauge
needle moves about 1 to 2 needle width from the set position indicator,
Can't remember the tank size but I had to go to the next size up as the
smaller one was borderline so might be 18L when a 12L was "just about"
enough.

Also the system temp never starts at "cold" as 50% is UFH and max temp
is 50 degrees so perhaps only a 20 degree difference between hot and "cold"

On 22/12/2014 17:41, John Rumm wrote:

In which case I would be worried about the home system ;-)

(are you sure its not changing by 1 or 2 bar rather than PSI)?

Ha... just double checked, I was thinking there were 7 PSI's to a bar !
so double that to 4 or 5 PSI or a 1/3 of a bar.
I was thinking much smaller volume in the lodge would give less pressure
variance not thinking the expansion vessel must also be tiny.

On 22/12/2014 18:47, www.GymRatZ.co.uk wrote:
On 22/12/2014 17:28, Andrew Gabriel wrote:

Doesn't seem right to me but at home I have a pretty big external
expansion vessel and the pressure only changes by 1 or 2 psi at the most
with significantly greater water volume.

Sounds strange. Are you sure that's not bar, rather than PSI?

Haven't actually measured the difference in PSI but the pressure gauge
needle moves about 1 to 2 needle width from the set position indicator,
Can't remember the tank size but I had to go to the next size up as the
smaller one was borderline so might be 18L when a 12L was "just about"
enough.

Also the system temp never starts at "cold" as 50% is UFH and max temp
is 50 degrees so perhaps only a 20 degree difference between hot and "cold"


You must have had to fill it and set the base pressure in a cold
condition at some time or other!
--
Cheers,
Roger
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