Hi i have a fault F28 on the above boiler and have discovered that the water level is bellow what it should be. I have a key to adjust the valve but am not 100% sure what to do - can anyone help?

L, July 2008

Hi Guys Just simply clean a ignitions lids. Make sure u sweeched off gas and boiler from main electricity supply.

Lucas, April 2013

Just found this post in desperation and wow... you legend hehe :) thankyoooooouu :0) it took me a while to locate the valve though as it was in a separate cupboard...hmmm.... But i found it and have solved the problem...for now... Thanks again!!!!

mary, March 2012

to fix this fault, underneath or around the boiler case somewhere, there is a little valve connected to pipe( in my boiler there is just one valve), open that valve carefully while keeping an eye on the Bar Gauge i said earlier. opening the valve MUST increase the pressure and push the gauge to the green area. when the guage hand reached somewhere betwwen 1 and 2, close the valve again and fire up the boiler... it should fix the problem....

Hadi, December 2010

Re Vaillant thermocompact bolier F.28 display - my stepfather bled my radiators around 6.30pm and by 10.30 the heating had stopped. I have attempted to reset the boiler via the instruction manual but it hasn't worked and the it tried to engage but no joy. The pressure has droped to below .2 (200) and reverts to the F.28 fault display. Any ideas? thanks

Ian, November 2010

the code f28 is shown the gas pressure is fine, wat else cud it b

Dave Nicholson, March 2009

hi i have the same problem, which valve do i open? i found a small leak which i have fixed..

shahid, December 2008

I have just had the same problem and the above was the answer. Thanks for this advice as some other remedies to this fault code looked expensive. Thank god it was easy as it is christmas eve and I am cold!!

Ally, December 2008

If preassure drops too far,on central heating, on vaillant, below 1 bar, then you have a small leak in one of your radiators or water pipes running between boiler and radiator.

To rectify you need to open a valve on a small link hose which is used to balance the preassure, usually located below the boiler somewere.

Open Valve slightly and watch pressure guage, and shut valve the moment the pressure reaches between 1 & 2 Bar, usually marked as a green patch on the guage,(Middle of 1&2). Remember not to put too much preassure in because when the boiler fires up the preasuure rises as it heats up, and too much preassure will cause more leaks in the central heating system

scfi, August 2008