Afetr long term use of the controler it has been working great but we do have days that the sun dont shine and so there is insufficient powe from the PV system to heat the water so a manual over ride is an essential eddition.

Currently I have to unplug the heater and plug it straight into the power point heat the water upa nd thn switch it back - PITA

I was goingto implement smart phone control but that means creating an app or soething else - hmm maybe i could use blynk or cayene to do the phone side - but adding a switch to the box seems like it might be more practical -

The Tank is mounted under the sink and and the controler sits on top of it so it is just a matter of opeing the door and pushing a button - easier than finding my phone launching the app and then pushing the button.

It only takes an hour to heat the water from cold so I will adda button that when pushed gives full power for 1 hour and then returns to auto opperation.

I thin ki will also add an LED to indicate when the unit is actualy activating as well. A bit of visual feed back helps. Curently the only way I have to tell if it is heating water is to look at my energy meter.

Just looking at my code - wow its bad :lol:

Ive already set D0 as an input but have nothing currently attached to it so I will use that a sthe swicth input

EEK - this is going to be rather nasty my main loop has lots of delays to give the Wifi connection time to do its thing which means if I just read the input each loop i could potentially have tp hold the switch in for 10 seconds :( not cool.

I dont want to rewrite the whol thing right at the moment. Maybe if the pin can trigger an interupt it might work.