\Hi there! I have one of
formatting link
modulating heating system( ecoTec plus 870 ) in my house. But as as I became convinced from my own experience that Vaillant modulating is not as cost- and energy-effective as it was described. In winter I was paying something like 450 pounds per month, but when I installed this heating the cost increased for 200 pounds! I don't know really why, but I want to do something with that. Is it possible to turn off modulating option? Or I need to change the whole system?