Lobster wrote:
On 21/01/2011 13:00, John Rumm wrote:
On 20/01/2011 22:12, Roger Mills wrote:
On 20/01/2011 21:23, Ron Lowe wrote:

P5 says the pre-charge pressure on the expansion vessel should be 4
bar.

THe 6 bar reference on P14 is the cracking pressure of the Expansion
Relief Valve.

Pump the thing up to 4 bar cold.


.. . . making sure that the 'wet' side isn't under pressure while you do
so.

which probably means shut off the mains inlet, and open a hot tap...

I assumed I'd need to open a drain cock on the CH to reduce the pressure
to zero, thereby losing all that precious inhibitor - is that not the case?

David


no.

shut off mains supply, and open two hot taps, one upstairs and one down.