central heating boiler

[corylus]

help please gasmen, how do I get the pressure back up in my condensing boiler after bleeding 2 radiators. Have tried inserting the screw tap under the boiler but can't get the pressure up.

[buildersmate]

Because you have removed water from the system (by bleeding) the pressure has gone down.
To bring the pressure back up requires putting some water back and turning on a tap until the dial gauge returns to about 1 Bar.
Some boilers have an insert that makes the mechanical link between the cold mains supply and the entry point for water into the sealed part of the system - and I think that is what you are referring to by 'inserting the screw tap'. Have you then found a way of turning on that tap? You will generally hear the sound of water flowing and the dial gauge reading gently rises.

[feebal]

I have to insert a 'key' into the bottom of my boiler to increase the pressure. I have to say that this is often quite a palavar as the key has to fit in a certain way to actually lock and work.

Are you sure you've inserted the screw tap in far enough? What happens when you turn it? If water comes out then it's not in properly.

[gasman]

On these boilers you have to insert the key and twist it a quarter of a turn to lock it into position and then just to the side of where you put the key in there is a small black knob that you then have to turnanti clockwise, you will hear water running and the pressure will rise. You need to reset the pressure to approx 1 Bar. turn off the small knob and unlock the key and remove it . That should be it corylus.