baxi 105E combi pressure rise.

[gazza247]

Hello there, I've got a baxi 105E combi thats gaining pressure very slowly, If I set pressure to 2bar It rises to 2.5 bar in about tens minutes. The heating works fine and the does hotwater hot water operates no problem. But can't figure out why the rise in pressure , Any suggestions are welcome. Recently changed both diverter seals as they were leaking this was about 3 months ago.
The relief valve opens and does its job, any suggestions please?

[Phoenix Heating]

only way pressure can increase is either........filling loop not closed or disconected, secondary hot water heat exchanger leaking (mains water getting into ch ) if ur boiler has one, not familiar with this model