I have a Garn jr. heating a 4,500 sq/ft home with 20 radiant floor zones. The first winter I just used one thermostat in the basement and manually dialed all the zones to heat the house as evenly as possible. To do this I had to dial many of the basement zones down, so that flow would be more even on the third floor. The basement has 7 zones that are pex in concrete on 12" centers while the rest of the house is 'sandwiched' pex in aluminum fin on 8" or 6" centers below 3/4" wood flooring. Some zones are short, others are 300' so I've had to dial down short zones and zones that are lower in the house that have less resistance. I'm using a tekmar 356 to control mix temperature and now I just installed thermostats and Calleffi operators on all the zones. Here is my question: Would you now turn all the manual dials to wide open and just let the thermostats and controllers and pump do its job, our would you keep the manual dial settings to choke off some of the flow to the easier zones? Option 1: Wide open - this probably is the fastest and most efficient at getting heat from the garn into my house. but when all the thermostats are calling for heat (because I was lazy and didn't build a fire) the flow will go mainly into the basement until it is all warmed up, then those zones will shut off, and it will heat the main floor, until those shut off, then it will heat the upstairs... Option 2: Keep the manual settings - this will cause the whole house to heat up more evenly, but it may not be the fastest way to get the house warm because most zones are restricted? The only reason this is really an issue is because I use a wood fired boiler and sometimes the tank temperature dips below the target mix leaving me with a house that has to go from say 62 to 70. how would you do it?