I've made a couple of posts about trying to get a timer control into an
old Vaillant boiler/central heating system.

My previous idea of just power-cycling the boiler seems to be a no-go
given that the boiler has (I think) a run-on function. Certainly, after
switching off the water and heating controls, the boiler continues to
make a noise for several minutes.

My question now is... what is this?

link:
http://www.flickr.com/photos/7204575@N04/2860583064/

There's no reference to it in the manual that was left with the boiler.

The two switches on the unit control the water and heating respectivly.
The dial appears to indicate water temp and the control knob sets water
temperature.

There are wires from the boiler to the unit, which, from their
connections, would imply that a new thermostat could be added to replace
the pictured unit.

However, before I dismantle it all, I'd like some idea of what's
supposed to be going on. But there are no part numbers on the unit, so
I'm struggling to get any kind of clue to google on.

So, does anyone know what this unit may be called? Or even maybe have a
manual?

Thanks & regards
Robin