If you had an electrical fire, what was burned?
Is the circuit breaker for the well pump on or tripped?
If tripped, you don't want to turn it on until you're prepared to put out another fire or you know that the fire was from combustion caused by the heat you applied to keep things from freezing; like burned insulation or wood etc.. That wouldn't be an electrical fire, that means shorted wires got hot and then burned something like insulation or wood etc..
Looking at the picture, I can't see anything burned at the pressure switch etc..
BTW, usually a plumber isn't a good choice for pump work unless he is capable and willing to pull a pump out of the well. A pump guy or well driller is a much better choice.
If your heating system works when you turn up the thermostat and the boiler fires up, the system is working.