New radiator nightmare

[countvoncount]

We had all of our radiators replaced last week for more energy efficient types.
Since then, the pressure on the boiler is dropping to zero literally twice a day and we have to re pressurise it.
There are no leaks at all anywhere, the fitters came again today, flushed the system and said all was ok...., it's just bloody gone again!
Anyone any idea what this could be please?

How old is the boiler, could it be the boiler itself (coincidentally but it could happen).

It's fairly new!

We had this happen to us and the boiler was knackered, it was only 3 years old. 😥

Oh bloody hellfire 😩
This is all we need

Could be the heat exchanger in the boiler. Ours was dropping pressure and that was the cause. Our boiler was quite old though — 10 years ish. It cost £360 to replace the part and Labour etc.