Why are there "dashes" on a Johnson A350R
The A350R has a feature that when the controller is in Warm Weather Shutdown mode, the boiler will not be enabled.
The warm weather shutdown is enabled by setting the jumpers on the right side of the controller. When the outside air temperature is above the setting, the controller relay will be disabled.
The -150 or some other large number in the display when you press setpoint (display is on right side of A350R) is the indication the controller is in this mode