I was talking with my A/C installer yesterday and he said I need a 5 contact thermostat if I want to control both A/C and radiant with the same unit.  Does anyone have any suggestions?

Mikeinnyc I will pick up a Wirsbo 501s for the basement slab, as that zone is heat only. 

I really need to get this system under some sort of control.  Having only one thermostat in the basement controlling everything means it runs all the time on the upper two floors (room temp at 85 this morning) when I shut the basement loops off (basement loops 55). Or the basement heats up, steals all the btu's, then shuts the boiler off.  Right now I have the upstairs loops in high speed, main floor off, and basement on low speed and the ball valves at half throttle.  I also turned the water temp down to 120 max.  I need to warm the house up so the primer coat dries and they can spray texture, but what I've got going scares me. 

Thanks,
Ben

Ben, Wirsbo has a heat/cool thermostat also. (WT-2) You can also use the heat only (WT-1) for the basement. Both good less $$ then the 500 series stats. If you need two stage heat and one cool on one thermostat you could go with Tekmar 545 or 546.

Ben,

Pricewise your better off going to Home depot for 20 bucks get a mickey mouse A/c w/ heat programmable thermostat. Unless money is no object ... you could get one RADIANT HEAT AC unit that does both, but that's way more money. The Mickey Mouse Thermostat will control your Wood Stapleup and AC during the summer. This will suffice. However, again you need a zone valve controller and Zone Valves/thermal ZV for independent control and or Pumps with IFC of which you have I do believe. Thus, you should be good to go.

For your upstairs a plain jane AIR thermostat will do fine. You don't need a slab sensor for a staple up...you could but thermal mass is so low that it's not going to make much of a difference. Currently you have jumpers on zone one two and three of which you will simply add your NEW thermostat wire to each of the zones dictated by the pump. You will power your therms from a 24 transformer pigtailed with all three thermostat Power wires. Make sure your 24 Trans can handle all three power hogging themostats. That's it. Three zones require three thermostats min instead on three zones with one thermostat. That's usually to test the system. You are now beyond that stage so go to HD or Lowes and get a Thermostat and end of problem upstairs. Your Slab ... you must use a slab sensor and air sensor. The slab is really what you will be controlling with larger themal mass of concrete.

Note: USE MULTIPLE WIRE THERMOSTAT enough for two independent 24volt thermostats. You'll be sorry if you use 3 wires or less use 8 wire thermostat ALWAYS for future use.

I alway use 8 wire spools so that I can run Temp sensors to the thermostat on each floor. I can monitor the Boiler Supply and Return temp (return is important for thermal shock) with alarms if the temp drops below 130 or whatever you set it. In the future if you want to get Sci Fi with your Radiant you will need extra wires. Do it now and pay more for 8 wire or you will be sorry later when you fish a new line. Fishing lines all power to lines must be off!

I also can monitor upstairs the Supply and Return Temp for each Zoned Manifold and the Delta T for each seperate zone all while looking at the 5' thermostat. Sort of like a Time wall clock. I know whats going on upstairs without going to the basement boiler room. Pretty cool features simple but way cool.

Your house looks air tight Ben. Good luck with the rest of it.

Mike