This is a Vaillant ecoTEC plus 831. It completely shuts down (screens off etc) at instant of heat demand. Never ignites. After turning it back on, even if no heat demand is made it will still shut itself down in a minute or so. Also any time it shuts down you will not be able to turn it on again unless you wait for 10 mins or so.
Any suggestions appreciated. Thank you.
Any suggestions appreciated. Thank you.