my vaillant ecotec plus 831 was installed in oct 07 and has been serviced annually by the gas safe engineer who installed it. i have had no trouble at all with it until now; it has just had a repair by a vaillant engineer as part of my homeserve insurance policy which has left me with a concern.
From day 1 the pressure gauge has always sat at the bottom of the grey (normal) area when cold and has increased just a small amount when hot. I have never until now measured it digitally as was unaware until informed by the vaillant engineer that pressing the - button provides a digital reading. The cause of the engineers visit was my noticing that the pressure gauge was reading up in the red zone. The following was noted; when cold the gauge read at lower end of the normal range; when working it rapidly climbed up into the red area. To stop it going into the red area I reduced the water temperature to 65 degrees which kept it just short of the red area. Research on the internet indicated a likely problem with expansion vessel pressure. The vaillant engineer confirmed that to be so on checking the expansion vessel and finding its pressure to be virtually zero. He re-pressurised it, replaced the pressure relief valve, carried out various checks and pronounced it fully serviceable after setting water temperature back to 75 degrees which is where I have always had it. It works fine but the pressure gauge when cold reads much higher than it used to at about 10 o' clock as you look at it and reads 1.5 bar when pressing the - button. When hot it reads at 12 o'clock as you look at it (just short of the red area) and 2.1 bar when pressing the - button. I would appreciate some guidance as to whether this is ok as it has never read this high in the past.
From day 1 the pressure gauge has always sat at the bottom of the grey (normal) area when cold and has increased just a small amount when hot. I have never until now measured it digitally as was unaware until informed by the vaillant engineer that pressing the - button provides a digital reading. The cause of the engineers visit was my noticing that the pressure gauge was reading up in the red zone. The following was noted; when cold the gauge read at lower end of the normal range; when working it rapidly climbed up into the red area. To stop it going into the red area I reduced the water temperature to 65 degrees which kept it just short of the red area. Research on the internet indicated a likely problem with expansion vessel pressure. The vaillant engineer confirmed that to be so on checking the expansion vessel and finding its pressure to be virtually zero. He re-pressurised it, replaced the pressure relief valve, carried out various checks and pronounced it fully serviceable after setting water temperature back to 75 degrees which is where I have always had it. It works fine but the pressure gauge when cold reads much higher than it used to at about 10 o' clock as you look at it and reads 1.5 bar when pressing the - button. When hot it reads at 12 o'clock as you look at it (just short of the red area) and 2.1 bar when pressing the - button. I would appreciate some guidance as to whether this is ok as it has never read this high in the past.
