The pressure on my 3-year-old Vaillant ecoTec Plus 630 seems out of control. Could it be caused by a faulty expansion vessel?
When cold, the pressure is 1.0 - 1.5 bar but, when the boiler is working hard, the pressure goes off the scale and water is ejected via the pressure relief valve. Then when it cools down again, the pressure is zero and I have to top it up.
Advice appreciated.
When cold, the pressure is 1.0 - 1.5 bar but, when the boiler is working hard, the pressure goes off the scale and water is ejected via the pressure relief valve. Then when it cools down again, the pressure is zero and I have to top it up.
Advice appreciated.