Purchased house in the last couple years and it has a Baxi ht 330 combi boiler. During summer months I get the e119 code requiring to pressurized probably once every 2 weeks. Winter time when the floor heat turns on I get the code probably every 2 days. Had a heating guy come out and I think my system intimated him as he didn't touch a thing and said they would have to have multiple people out to run a pressure test on the system. He was nice enough to charge me for the service call. Not saying that does not have to be done to figure out the problem. I see on multiple forums people experience these issues due to the internal expansion vessel, I have no external. Opened up my boiler today and it looks like it has leaked in the past out the side see pic. I mentioned to this heating guy about seeing multiple people indicating expansion vessel issues which he reported if there was a leak it would be coming out the pressure release valve. I plan on getting someone else out to check but what do you think should the expansion vessel be replaced prior to further leak testing?