Posted by mikey00 on June 27, 2001 at 13:24:30:
I am currently receiving bids to replace my 50 year old oil boiler with a gas one. Main zone is 100 feet of cast iron baseboard. It is a mono-flow system (1 inch pipes loops around entire house with each section of baseboard tapping off of it). Second zone is 24 feet of cast iron baseboard in basement (straight run). Third zone is for a blower for garage. Fourth zone is for a proposed indirect water heater. Currently there are 3 circulators but they are old. First bid says you must use 4 circulators because it is a mono-flow system. Second bid proposes zone valves and one circulator and says they are ok with mono-flow systems. Also says that there are no 1 inch zone valves but 3/4 inch should be fine on the line. Who's right?