Central Heating Pressure Loss

[oldcrappyheating]

Hi,

maybe someone can shed light on this, I am at a loss ...

we have a fairly new condensing gas combi boiler (worcester bosch), it has only been installed 3 month ago. Since the Christmas break I notice that the pressure drops rather quickly (from 1.5 to less than 1 in a week). I can't find any leaks. The towel warmer (highest rad in house) seems to collect some air in the top rail).

What I observed, and that really puzzles me, is that the pressure stays kind of ok as long as the boiler stays on. That is over the weekend when the boiler is on most of the time the pressure kind of tsays (a bit hard to tell if it goes down a wee bit) but during the week when we have it on in the morning for 2 hours and then again for 3 hours in the evening the pressure drops much faster (the drop is actually visible on the gauge).

Oh yes, and the overflow seems to stay dry ... so what happens

S

 

[ollski]

possibly pointing out the obvious but you know that the cold pressure at 1 bar will increase to around 1.5 when the heating is hot and also that when you bleed the air out you are dropping the system pressure and will need to top it up after.

 

[doitall]

Check for small leaks around the rad tails etc when the system is cold

 

[croydoncorgi]

Also, on some boilers the pressure gauge will read higher when the pump is running.