"EricP" wrote in message
...
On Thu, 2 Oct 2008 23:39:53 +0100, "fred" wrote:

What kind of variation should I expect between off and running?
Off (cold) it's about 1.5 bar rising to around 2 bar when hot.
New system, Worcester Bosch Greenstar 30cdi
Cheers.

i have my (halstead combi) at 1 bar cold, it goes upto 2 bar when hot,
prolly a result of the mix of 15mm an 8mm microbore pipes in the system, (2
rads are on microbore, the rest on 15mm, why i dont know, but the ones on
the microbore heat up faster than the 15mm ones)

The central heating in my motorhome sees an even larger cold to hot pressure
differance, but that runs at 85 degrees C rather than the 55 a home system
runs at,