After trying to get my heat working in my otherwise "perfect" 95 E300D,I replaced the ACC Monovalve,guess what :nothing happend...shop cleaned the
whole heating system,lines,core...and found DIME SIZE RESTRICTION that somebody installed on purpose right before heater line gets to the firewall,took it out,heat works line new...just 600$ out of my pocket(400$ useless part and 200$=3 hour labor),sick people to restrict a heater ,when you can just turn it off...climate control works perfect,will close the heat no problem.