Vokera Linea 28 Automatic Air Release Valve Leak

[Poshgeordie]

Vokera Linea 28 Combi.

I recently emptied the central heating so as to renew a couple of radiators.

When I refilled the system, the automatic air release valve (item 25 on page 1 of the Linea 24 & 28 Installation and Servicing Instructions manual) badly leaked water out of the top adjustment screw.
The only way to stop the leak was to tighten the screw down.

Prior to carrying out the work, when I pressurized the system to around 1 bar and then ran the central heating system, the pressure increased to between 3 and 4 bar.
No safety valve ever blew.

After fitting the radiators, with the screw tightened down to stop the leak, when running the CH the pressure now only rises to about 2 bar.
Also subjectively the radiators actually feel a lot hotter (cold pressure again was 1 bar).

There are no leaks or pressure drops in the system.

Please could you tell me what the problem is and how to sort it out.

Many thanks in advance

Nick

 

[nickso]

see the faq's for expansion vessel problems. could be the pipe that feeds it if the pressure in the vessel is ok as they are prone to blocking on this model.

the auto air vent is an easy fix on this model. just screws out of the pump housing, wont be expensive for you to replace.

 

[Poshgeordie]

Many thanks Nickso.

To check if the pipe is blocked, are you referring to the flexible pipe from the air vent?

The service manual doesn't appear to mention repressurising the expansion vessel. Do you know the location of the pressuring valve?

Thanks once again.

 

[nickso]

to repressurise the vessel, drain the boiler and leave the drain open to release excess water/pressure. connect a footpump to the valve on the vessel (top of boiler, down the back a bit under the flue, might be left or right side), oump vessel to 1-ish bar and repressurise the boiler to 1 bar after closing your drain.

it is the small braided pipe next to the air vent,the pipe may not be blocked, im just saying its common enough to keep in mind. if you get no water or air noises from your drain as you pump the vessel there is a good chance its blocked.

 

[Poshgeordie]

That's great - many thanks.