baxi 105E condensing boiler.3 years an old. losing pressure for 5 months now. adding water every day now as drops to red zone.no leaks found under floors except for one room (tiled and pipe under concrete )
One engineer told me to switch off boiler,put a bag on outflow pipe, increase pressure to 2 bar and watch!
Bag filled with water and pressure rose to just over 3 bar.Does this prove no leaks in pipe work?Been told system prob full of sludge (heat exchanger just changed as hot water kept fluctuating hot/cold) desperate now as £400 down and still not fixed.

Andrea, March 2010

top pressure up to 1.5 on pressure guage do this when system is cold to get a true reading switch on heating and watch guage if it goes up to 3 barr or over it could be one of three things ,expanssion vessel, filling loop letting by or plate heatexchanger if plate heatexchangers been changed that elimenates that try setting correct pressure again to 1.5 then if you can disconect filling loop and see if it leaks if not it will proberbly be the expanssion vessel if you like call me and il talk you through it 07923258885 between 9 and 4

john, March 2010