Your post suggests the need for further checking. I don't have a diagram of the thermostat. If the circuit is 220V (220-240V) and you only were able to read 118 volts at the thermostat, then I suspect the problem is an open circuit at the power source or cable leading from it. A number of times I have traced an open circuit to a splice in which one wire has become slightly separated from the other(s). This can happen even years after the installation.
