Need help identifying temperature sensor.

Hi guys, I just purchased my first house and I have 4 thermostats in the house that I want to replace with the Ecobee4. I am not an expert in HVACs, air conditioning systems, boilers, etc. I am a novice and I am learning as I go along. So please be gentle when replying to this post so I can understand your answers. I appreciate your patience! :) I have an Energy Kinetics System 2000 boiler. I don't 100% understand how my A/C system is set up, but I think I have two A/C handlers in the attic and I definitely have two A/C condensers outside. The A/C has two zones in the house whereas the heating system has three zones. Here are the thermostats: 1) Family Room: Controls A/C and heat. This thermostat has the RH, RC, Y, W, G wires. 2) Dining Room: Controls heat on the main level. This thermostat has the R and W wires. 3) Master Bedroom: Controls the heat on the upstairs level of the house, where the bedrooms are. This thermostat has the R and W wires. 4) Hallway: This thermostat controls the A/C for the main level and upstairs level of the house. This thermostat has the RC, G, Y wires. I do not have a C wire or extra wires to convert into a C wire for any of these thermostats. I spoke to both Ecobee support and a technician from Energy Kinetics (who makes the System 2000 boiler). Energy Kinetics sent me this PDF: [url]http://energykinetics.com/wp-content/uploads/2015/11/Nest-Power-Sharing-Wiring.pdf[/url] They also said: The Ecobee t’stat is compatible with our System Manager as a Heat only thermostat it cannot be used for Heat and A/C without an isolation relay. The connections for heat only are A2 to C, A1 to R and W to T1,T2,T3…. See diagram I attached labeled Nest thermostat. The Ecobee requires power all the time so you will need a three conductor cable running to the stat or you can use the Common Maker from Fast Stat if you only have a 2 conductor cable. [B]Family Room[/B] If you are going to use the Ecobee thermostat it will require an isolation relay see diagram for installation [B]Dining room[/B] No issues if using the Ecobee you will need three conductors connected to the Manager A2 to C, A1 to R, Tx to W (Tx is whichever zone t1,t2,t3…) [B]Master Bed room[/B] Same as Dining room [B]Hallway[/B] has no heating connections Ecobee support told me this: As per the explanation , if you have 2 different systems , that is boiler and a AC ,controlled by 1 thermostat , it becomes a Dual transformer set up . In this set up , ecobee will have the following set up : R wire from AC >> RC Y wire from AC >> Y1 G wire from AC >> G C or spare wire from AC >>C R wire from Boiler >> RH W wire from boiler >> W1 Please note that C wire should always come from the AC/compressor unit . So, I am a little confused since it's getting a little technical for me and I am new in trying to figure this out. 1) Can anyone more knowledgeable than me try to dumb this down and explain it in more simpler terms? 2) It sounds like no matter what, I need to hire an electrician to install C wires if I want all 4 ecobee thermostats to work? 3) If I need to have C wires installed, how much would something like that run? The ceiling in the basement where the boiler is located is exposed. Is it possible to run a C wire down the wall from each thermostat without breaking into the wall? I know this is a long post, but I appreciate any help you guys can provide. Thank you so much!

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