The wiring to the thermostats in my house 14/3. The white wire is connected to the transformer load screw. The red is attached to one zone valve and the black to the other. The 14/3 wire runs to the thermostat on the first floor then from there to the second floor thermostat. My problem is this: the wire running to the second thermostat was cut. Since there is no slack in the wire I am faced with either using 2 j-boxes to reconnect the wire or trying to run new wire which will be difficult. Could I reconnect the wires with tape and not use j-boxes since this is low voltage? Also, could I replace the 14 gauge wire running from the 1st thermostat to the second with low voltage wire and leave the 14/3 in place from the boiler to the first thermostat?