I'm looking at boiler replacement job with a total house load of about 75,000 BTU's. I'm thinking about a mod-con with a buffer tank. The house has 6 existing zone and a 80 gallon indirect, the zones are kinda small and only doing a couple rooms each. They have a interior bathroom that has a radiant floor which is about 1,200 BTU's.
How would you guys pipe in this radiant zone? Mixing valve? I series valve? something else?