Vokera gas boiler pressure guage dropping frequently.

Jeepers_Creepers

Hmm, good point Eamon - if the exchanger is cracked, then some (perhaps all) of the leaking water will be boiled off and sent out the flue.

Crimson did say before; "As well as the white pipe outside there is, higher up, a round much bigger pipe and sometimes it sends out puffs of steam." 

Crimson, could you post a photo of the actual boiler, please, so we can hopefully ID it? Any letters/name on the front? Do you have instructions for it - what model does it say on there?

[Deleted User]

Sorry for the long silence but I have just taken two photographs today -

  The Boiler is Compact 29 and the small unit on the wall iin the kitchen close to the Boiler iss Danfoss RX1.  The timer unit in the living room just says Danfoss.I filled the 'tap' to 1.5 on Friday.

I hope the photograpahs show up all right, thank you.

Crimson

Jeepers_Creepers

Thanks for the info. Not sure it helps me tho'... :-(

That wood panel under the boiler - can that be opened or removed to expose the pipes as they come out from under your boiler? If so, there is one other thing you can try, but you need to be happy to do it (not difficult or dangerous, but you just need to be 'happy'.)

IF the boiler also loses pressure when it's off and cold, then you can try this test if you can leave the boiler off for a few hours; under the boiler you need to identify the two central heating pipes - the flow and return. They will be 22mm copper, look identical, and have stopcocks on them where they leave the boiler. (I think they might be on the LH side of the boiler, from seeing a pic on t'net?) The idea is to SHUT DOWN YOUR BOILER by turning it fully off at the front (and at the isolating switch too if you think anyone could turn it back on), pressurise your boiler - perhaps up to say 2 bar to give it a good test - and then shut off these two valves by turning them off through 90o (make sure you turn them fully quarter-turn).

Then leave. It's perfectly ok to leave it like this if you go out - nothing will go wrong as the boiler is off.

If the boiler still loses pressure with these two valves closed, then the leak is almost certainly within the boiler. If the pressure does not drop - but then does when you reopen these valves, then the leak is def in your pipework.

When you are done with this test, just open both valves again and turn on.

[Deleted User]

I cant believe I've just lost a whole post, Jeepers_Creepers - I was distracted and lost what I had typed.   Thank you very much for offering further help but I really   would be too anxious to try - I'm even wary of moving the wooden panel, as I have to, to top up to 1.5 when needed. 
Once the lockdown is over I'll be able to get a Gas Safe engineer to check.  I'm reassured that, in the short term, I'm not damaging the boiler by topping up as a temporary measure.

I appreciate all the good information and time you have given, thank you.

Crimson

Jeepers_Creepers

No problem.

Yes, it should be fine to keep using it. Not ideal since you'll be diluting the protective inhibitor in the system water, but a few months won't hurt :-)

[Deleted User]

Thanks for all your interest and for the reassuring help.

Best wishes to everyone for, albeit very different, a safe and happy Christmas - and better New Year in 2021 - Covid free.

Crimson