Turn boiler off and turn back on whilst holding + & - buttons. Keep holding until display reads P0, let go and press i button.
Boiler will self purge.
Worth a try, takes about 5-10 mins. You may have to top up pressure afterwards. Make sure trv's are open first.
As others have said, have you noticed any water out of the prv pipe?
Was this a boiler change or a complete new ch system? If complete new I would have thought the installer would have air pressure tested system before filling.
I always test mine to 3.5Bar for appox 1 hour. I'm too old to run round looking for leaks when I fill up anymore