Vokera Excel 80SP.......... Heat -v-Pressure Problem

[JT569]

Have 9 year old Vokera Excel which seems to have developed a problem recently.

The radiator heat dial on the boiler is set at about the 3o'clock position, the water is set the same.
When the heating is in operation the pressure rises to @ 2.5 bar on the right hand pressure gauge, with the hot water on as well there is little difference to the pressure reading.

However , if I turn the radiator dial up, say to the 4 or 5 o'clock positions the right hand pressure gauge rises to / passes the red line marking 3 bar pressure.

While everything works fine at this point after the time clock swithes the system off and it has cooled down the right hand water pressure gauge drops into the red area between 0.5 and 1 bar of pressure and I have to fill the system up again to get it into the blue ( 1 to 1.5 bar)

Has anyone had similar problems or can suggest a cause /solution.
Thanks

 

[gas4you]

Sounds like the expansion vessel needs re-pressurising or replacing.

Search FAQs on how to check this. It is well documented.

 

[JT569]

Thanks. The only thing is I'm new to the site - how do you access the FAQ section that you mentioned?

 

[gas4you]

Plumbing and heating front page, 6th down from top.

 

[JT569]

Got it .........thanks ..........fingers crossed