"John Rumm" wrote in message
...
The Natural Philosopher wrote:
Matt wrote:
On Tue, 10 Jul 2007 17:00:05 +0100, Mike Barnard
wrote:

My Worcester Bosch boiler cannot be activated by external zone
controls. So says the techie's at WB themselves. I've spent hours
and hours and a couple of hundred pounds doing the zone thing. I tried
to sort the controls today and couldn't figure out how to connect them
to the boiler. So I called WB tech support and my boiler (which is
only 2 years old FFS!" cannot take it. No way. "Can't I bodge a
control in somewhere?" Nope. The text display controls it all. There
is no single 'lightitupnow' connection in there.

What crap. WB Tech support are wrong.

What model boiler is it?


According to what I found, they are sadly correct.

There must be something that the TR2 can indicate that tells the boiler it
is getting a bit nippy in the room though, causing it to turn on. So the
next question is how to simulate that.

No need to just open or close a circuit. It "appears" that there is no link
on the TR2 connections at the boiler. This means on open circuit the boiler
is "on" permanently. Connect it and a resistance appears and the controller
acts accordingly to turn on or off, or modulate the burner (haven't looked
at this boiler in detail so it may or may not modulate the burner via room
temp). So closed circuit means boiler off. Opening and closing this
circuit to have the boiler on or off will work. When open the frost aspect
will be disabled, but an external frost stat can be fitted if need be. When
on, burner modulation is activated if a part of the control system as the
circuit and the TR2 is in circuit.