I've finally got the motivation to get back on this project. 

I've hooked up wires to the serial bus inside the pump and connected my OLS logic analyser to try and decode the signals. 

I think i've figured out the pump state, heater state, blower state and temperature in C and F from the recorded signals.

Last night I built a prototype of the hardware required to interface the ESP8266 3v3 to the pumps 5v bidirectionally.

Tonight I'm going to carry on writing the code for the serial decoder.