Hi, I've been reading threads and I'm still a bit confused. Hope you don't mind looking at my unique situation. I have a boiler with radiant water heat. Passed through taco valves controlling two zones. I wired an Ecobee3 on the first floor easily because the wire in the wall contained 5 wires. Second floor only has 3 wires. So I need to use a relay to add the 3rd common. I just don't know exactly were to put the relay? Before the taco valves or after? Here is a drawing of the existing wiring. [ATTACH]74055[/ATTACH] And a drawing of my assumption of how this should be done. Please correct me if I'm wrong. [ATTACH]74056[/ATTACH]

Hi Bought a house on Whidbey island, little to no heating help on the Island. House has a complex heating system. Oil boiler sends hot water to a mixing valve, thence to the whole house, then some goes to fin tubes in the majority of the house and some goes to another mixing valve that feeds an infloor system in one room. So two mixings. First mix is controlled by a Tekmar 363. I think I have most of the 363 settings figured and are Ok. Can achieve 72 degrees in all rooms when ambient outdoor is about 40. But at ambient 30 can only achieve high 60s. This may be good enough but am wondering what 363 settings could be changed to get 72 at ambient 30. In particular Mix Max is 200 Mix Min is off Boil Max is 200 Boil Min is 150 and I think the boiler aqua stat is 180. Is this enough info to comment? thank you