Can I use a Nest E to replace my existing thermostat?

[helvetios]

I have some Danfoss wireless thermostat that needs replacing, the receiver by the boiler has partially been melted and the controller intermittently works.
I'm considering going for a smart thermostat and maybe a Nest E as I can get one super cheap but unsure if it's suitable with the wiring I currently have.

I have 4 wires in use, two going to N and L (Blue and Brown) then two going to COM and ON (Black and Grey).

Any help is much appreciated, I'm holding off on my purchase till I'm 100% sure it is suitable or if not what would be better?
My current setup still works so not in any rush.

 

[ianmcd]

you can use stat you want, the nest e is to replace an old 2 wire thermostat, but as you already have a receiver and existing wiring you can use anything