Combi leak?

[Driver123]

Last March I had my old back boiler replaced with a combi boiler. I think I remember having to top up the water after a couple of weeks by 1/3 of a bar or so. I then kept an eye on it throughout the summer and the pressure never dropped so I thought all was well, until yesterday when I realised a couple of the radiators needed bleeding. After bleeding them the pressure had dropped at least 1/2 a bar. Is this normal over a period of around seven months? Does a new system need topping up after a while anyway? There are no signs of leakage.
TIA

 

[oldbuffer]

When you bleed a radiator on a sealed system you reduce the pressure, and have to top it up afterwards, or from time to time during the process if bleeding several radiators.

 

[Driver123]

Yes I understand that but doesn't air in the system suggest I have a leak? Or does it sound normal after several months? Do new boilers need to be topped up after a while due to the system being drained and refilled?

 

[dpgas]

Sounds about right. Filling up the system with fresh oxygenated water will mean that air will form and find its way to high points in your system. It would have shown sooner if you were using the heating.

Monitor it going forward but at the moment I wouldn't be concerned.

 

[Driver123]

Thanks for your reply. That has reassured me that it could well be normal. I will keep an eye on it. Cheers.