[?] Worcester-Bosch Greenstar boiler - pressure adjustment.

We recently had a new Worcester-Bosch Greenstar boiler installed and when it was commissioned the CH system was pressure-flushed and checked OK. I was told by the installer that the system normally runs at 1Bar pressure and was shown the white tap and square-headed screw underneath the boiler which are used to readjust the pressure if it drops. Unfortunately I didn't pay enough attention to this at the time and now I cannot remember the correct way to top-up the pressure.
I found that there was some air in one of the radiators a few days ago and when I 'bled' it out I noticed that the boiler pressure reading has dropped slightly so I would now like to correct things.
I'd be most grateful if one of this NG's experts could tell me the correct way to use the white tap and square-headed screw to re-pressurise the system. I'd also appreciate knowing how much the indicated pressure readings should vary between the boiler being idle and when it is supplying hot water drawing a bath,
Many TIA - Dave
--
David C.Chapman - ( snipped-for-privacy@minda.co.uk)
--------------------------------------------------------------------------
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
David Chapman wrote:

I posted this a while back. It refers to a 24i junior but maybe yours is the same
"Just for the archives, the built in filling loop for this boiler operates as follows: Shove the plastic key up into the hole to the right of the white plastic nut, turn clockwise (it locks at about half a turn). Then turn the white plastic nut anti clockwise to fill the boiler"
IIRC it needs a bit of force to get the key all the way into the hole
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

On my 28iJunior, I didn't like the position of the filling loop, so I left it on and kept my old filling loop arrangement
--
geoff

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.