Valliant 824E - reduce mains pressure

[Grazza]

My mothers valliant 824E has been losing pressure over a period of time, I occasionally increase the pressure by turning a screw on the underneath of the boiler, to approx 1.5 bar.

Had a call today, to say the pressure was approx. zero bar, couldn't go round myself, so sent the wife, unfortunately she turned the screw too much, realised her error, and so switched the boiler off. I visited tonight and discovered the following: -

The pressure needle reads about four o'clock, way over the red!
I cant turn the same screw the other way, i.e. to reduce the pressure
Water is running out of the relief valve into an external drain.

There seemed to be a tap/adjustment on the relief valve, and when turned slightly, the pressure drops down to normal, but water is still being expelled.

My main question is, is it safe to use in this condition?
Is it normal that you cant reduce the mains pressure by turning the same screw that increases it?

The diverter valve was replaced 3 weeks ago (no hot water from taps), dont think this is related?

Im obviously not a plumber.

Thanks in advance.

 

[Agile]

When you stop adding pressure the pressure stays at the highest you set it too.

Forget about times, its only the pressure that interests me.

The pressure relief valve opens at about 3 Bar and releases any excess pressure.

Generally it will manage itself if you leave the pressure too high and its safe to use it.

You must NOT leave the filling loop open as this will rapidly degrade the heating system.

Tony Glazier

 

[Grazza]

Appreciate the swift response. The pressure is currently well below 3 bar, but relief valve is still open.

Im unable to turn off the filling loop, the screw will not turn in the opposite direction!

 

[Agile]

There are two screws and they only turn 90*.

Tony

 

[Grazza]

I will try to locate the other screw tomorrow. Thanks for your replies.

Graeme

 

[Grazza]

Engineer arrived today and managed to turn the screw to reduce the pressure, (now why couldn't I do that) the correct key was also fitted to the screw to make it easier to adjust. I think I was just too scared to apply the correct force in case I broke it!

Anyway, all's well now, thanks to the people who replied to my original request.

Excellent forum.