The circulation pump is separate. I am really after measuring the oil component, for energy and for tank refill prediction. The electrical side of the heating I will lump in with all the other electrical items on a single pulsed power meter.
I am now thinking I can add a few lines of code to the pulsed power meter sketch to flash an led every 1000 millis, from a digital output pin. I then connect this pin via a relay to the digital input pin of the original sketch. This relay will close when the boiler is firing thus permitting the 1 second pulses into the sketch and for it to count as normal.
Any ideas?