So how likely is it that topping this up will make it fly off and/or leak somewhere else? I'm not a boiler guy and can't fix these things and so if it's even fairly likely to bite me in the rear I'll give it a miss. I guess these boilers are just crud?
Anyone? Just need to change a little rad, then re-pressurise. But have loads of work on, not desperate, so if toppng up this particular boiler (on a friday afternoon) is likely to give me leaks and dramas I won't bother.
As Dave1 says just turn it and it will fill up it will leak a little from the left until you turn it off again its only a leak while filling. maybe put a bowl or a towel under it while you do it
it actually looks like the extension tube is missing from it, there is normally a little blue tube that comes down further than that. unless its the photo