How to increase boiler pressure from hot water tank in cupboard

EZ26

Hi, I have a problem with my boiler that has 0.1 bar on the pressure gauge.

The boiler doesn't have a filling loop but I remember that a few years ago a plumber used one of the knobs shown in the pictures to increase the pressure but I can't remember which one he used and what he did exactly.

I think it could be 2 or 3 but not sure.

Can anyone help me figure it out?

Thank you for your help.

Wearb

It might be number 3.

EZ26

Thank you, do you recon I just need to turn that and the pressure should go up? Or do I need to do something else?

Wearb

Probably just that. Do it slowly so as not to over pressurise. If it's the correct one you'll hear/feel water go through it as you start to open it.

Don't over do it or you'll cause other problems. Also it's not a certainty that it's that valve, but try it anyway and then put it back to where it was.

DRedford

I'd say 4 first (it's closer to the boiler) then 3.

It's also a good idea to turn all valves every now and then so they don't seize up from limescale. Half a turn left and right would be enough for that style.

10-10-20

There's what looks like an NRV on three, so I guess three also. This might be a low-pressure closed system if that feed is coming off the attic tank though. Might not go up much in terms of the pressure.

EZ26

thanks all, 3 is already all turned clockwise, so I think it means it's already all open? I didn't touch 4 yet and yes the pipes all go up to the tank in the attic.

In any case it seems you all agree that by finding the correct knob the pressure at the boiler should go up?

10-10-20

Turn off tap 3. Can you tell where it appears in your attic? Does it come off a tank, do you know? Then hit that NRV (non-return valve) below valve 3 a few times (good sharp taps) with the handle of a screwdriver and then slowly open the valve again... see if you hear the rush of water.

EZ26

unfortunately that didn't do anything, I couldn't hear any water flow either. As far as I can tell the pipes go into the attic where there is the big water tank.

One thing I forgot to say is that when the heating is on the pressure goes up to 0.8 bar, but I guess that's too low, and from what I know it should be at 1 bar when turned off. As of now everything seems to work but I don't think it's a good thing to have it at that pressure in the long term.

It's so frustrating, I don't know what that guy did that time, but it didn't take more than few seconds to increase the pressure.

Would more detailed pictures help?

I've also just noticed that right after the boiler turned off, I could hear noises in the pipes, like if there was water flowing and then the pressure started to go down again. It goes to 0 in 20/30 minutes.

Wearb

https://www.boards.ie/discussion/comment/121669778#Comment_121669778

All the way clockwise is off, so 3 is turned off. You need to turn it anticlockwise a small bit.

EZ26

I tried both ways, all the way but nothing happens.