Combo Boiler sounds like it keeps filling the system with water

[Suzylee]

I have a Worcester Bosch boiler and on a regular basis throughout the day it sounds like it is filling the system with water. I have checked for leaks and can’t find any. The pressure is at 1 (the heating is on). I have bled the radiators I can access. I’m at a loss. Help! Suzy

 

[CountryFan]

Could you elaborate? Does it lose pressure? Does it have a flue gas heat recovery system? Are you able to record and upload? Could be blocked or semi blocked condensate pipe.

 

[foxhole]

I have a Worcester Bosch boiler and on a regular basis throughout the day it sounds like it is filling the system with water. I have checked for leaks and can’t find any. The pressure is at 1 (the heating is on). I have bled the radiators I can access. I’m at a loss. Help! Suzy

Does the boiler have a pre-heat option on the hot water side? Could be what you are hearing .

 

[opps]

I am not a plumber, but I believe that combis when heating domestic hot water, will use the central heating side (secondary heat exchanger) to dump the heat once the hot tap has been closed.