The ideal boiler pressure should be between 1 to 1.5 bars on your pressure gauge when your heating is switched off. Around 2 bars is a normal pressure level when your boiler is active/heating up. Anything below 0.5 is too low and must be replaced.
Why does my boiler pressure keep dropping?
It’s not uncommon for your boiler to lose a little bit of pressure slowly, and this can usually be resolved very quickly by repressuring the system.
But a rapid drop in pressure, or a repeated drop after you’ve repressurised, usually means that there’s a problem somewhere. You can book your repair here.