Can water in a combi system migrate from CH to DHW?

[JohnHuson]

Thanks for the help so far regarding the post on a leaking 26CDi. Just to remind you....PRV replaced. Loss of pressure but runs fine otherwise when charged. Pressure loss seems to be when CH is running but not yet checked this thoroughly.
Your comments have been appreciated but am still not clear which component to look at next.
If the diverter valve was allowing pressure to migrate from CH how long would it take when DHC is running to reduce boiler pressure?
Thanks again for your help.

 

[kevplumb]

If the diverter valve was allowing pressure to migrate from CH how long would it take when DHC is running to reduce boiler pressure?

diverter valve has nothing to do with it

if you are getting transfer of water between ch and dhw

the secondary heat ex is passing

 

[JohnHuson]

Thanks for comment on the Exchanger. If pressure is escaping via the condensate is this easy to test? There is warm water evident but in normal operating conditions what quantity of condensate would you expect to see going to the drain?
Thanks.

 

[gas4you]

anything up to around 2-4 l/hr

 

[kevplumb]

if its escaping via the condensate

it will still be dripping when the boiler is off