Increase pressure in Vaillant atmoTEC classic combi boiler

[wobbly_wheels]

We have error F.22 and can see the pressure gauge is low for the CH system. Boiler has shut off for both CH and HW. I've used other combi boilers before and had no trouble increasing the pressure, but I can't work it out with this one, is someone please able to help?

From what I can tell, the middle grey valve is for gas, the middle right is for water. I have tried turning those two valves (yes I know it's not a gas related problem) and the two small screwdriver valves on the far left and right pipes, none have any effect. I've checked the FAQ's on here and looked at lots of youtube videos etc, but none seem to have the plumbing layout we have.
Attached photo of underside of boiler. Any advice appreciated
EDIT: I have found this PDF which appears to be the right setup, but we are missing the valve 1 (or at least the adjuster), there is just a round pin which I have tried pushing in, but not been able to: https://www.mannsbarth.at/upload/1969190_Vaillant atmoTEC classic - English.pdf
EDIT 2: Added a more useful photo with my version of valve 1 from the PDF. Any thoughts on how I could open this without an adjuster fitted to it?

 

[MrTherm]

The small round grey handle is indeed your water inlet to the boiler and must be turned anti- clockwise to open, also at he same time manually press the small brass plunger button above on the same pipe. - 1 bar on the pressure gauge will get you working. Close grey valve when complete.

 

[wobbly_wheels]

Thank you for that. I have tried as you state and not got any movement on the gauge. The grey handle opens easily, the brass plunger is pretty hard to press in, but I have got quite a bit of movement on it before it gets impossibly hard (I presume fully open). I can't see anything else which could be stopping the flow in the pipework before the boiler, could there be something else that needs doing too?

 

[MrTherm]

If you turn on a hot water tap and let it run, then if you turn off that small grey valve and the water stops flowing from the tap, it will confirm the grey valve is *NOT* the filling valve (sorry)

If so you need to obtain a flexible filling loop and connect one end to a water supply and the other end to either the left or right hand valves after first removing the brass cap.

Strange if there isn't a nearby supply point ?

 

[wobbly_wheels]

Ah, that's it. That small grey valve is for hot water as turning it off stops "hot" water coming out at all. There isn't anything here for connecting a mains supply in temporarily. Could it be connecting left and right pipes, by the red valve on the left and grey valve on the far right? The grey valve is labled as 3 bar which tallies with the gauge on the boiler, and the un-covered screw fitting has a down arrow for flow direction. I could get a flexi pipe and try it?

 

[MrTherm]

Glad to see you're thinking in the right direction . . . but, that "open ended" valve looks to be a pressure relief valve, they are normally set to blow off at 3 bar, the open end normally would be piped to a safe anti blast position or to outside.
The pipe on the left of centre, is that a domed cap i cap see and does it come off or unscrew by hand? - go carefully!

 

[wobbly_wheels]

Ok, I'll steer clear of the open ended valve. The far left outlet cap comes off by hand, as does the far right on the same pipe as the relief valve, so it looks tempting to link them, but I thought that was usually a fixed pipe... Every day is a school day. Do you think that would be safe to try? Assuming the far left pipe is mains pressure and the far right is the closed CH circuit?
The left of centre dome is not a cap, the cranked pipe heading upwards is actually the same piece (or joined very cleanly)
I haven't managed to get a flexi pipe yet, so will have to see tomorrow now if possible.

 

[picasso]

Try pressing the small brass pin with a pair of pliars as that is the cold supply to the heating system, if pressing it does not work try pulling it

 

[MrTherm]

there could be a part missing as in this youtube clip

this is a German supplied boiler, i've also read it can be vented or unvented and parts /valves etc' are requested on initial installation. so as the associated link pipework appears to be non existent !!!

 

[wobbly_wheels]

Yep, that is one of the videos I found too. Given we established closing the grey valve fully on the same pipe stops water for the hot taps, does this mean that pipe can be for both HW and CH?
I've got a pretty rudimentary set of tools here (short term rental), I couldn't get anywhere with pulling the brass pin, not sure if that's because it can only be pushed or I couldn't get enough purchase on it, but pushing does move it, it just has no effect on the system

I've tried to get though to our landlord, if it's not that clear then it's probably best for us to wait for him. I'll let you know how it goes! Thanks for all the input so far

 

[wobbly_wheels]

So I went with the logic after I found what looks like washing machine hose jubilee clipped onto the correct adaptors stuffed behind the radiator in the bathroom and, via the covered valve on the right side and a spare (dishwasher?) outlet, I have managed to get 1bar of water into the system!
When doing so I could hear lots of air, but it's not in the radiators yet. Is there a way to bleed the boiler or do I just have to wait for it to get around to the radiators and keep an eye on it for a few days?

 

[wobbly_wheels]

All up and running again now, radiators don't seem to have any air still, but I'll keep an eye on it. Thanks for the help from both of you!