"Andy Hall" wrote in message
news
On mine, there is an outside sensor which goes on a north facing wall
out of the sun and gives the boiler a temperature signal based on
resistance. There is an inside controller which senses temperature
and hooks up to the boiler with a pulse width modulated digital code,
in effect providing an analogue temperature value.

It is possible to set the proportional bandwidth and the relative
sensitivities to each of these terms, with data being accumulated over
several days. The boiler output is then linearly modulated from 3kW
to full power by controlling the fan speed (influences gas input rate)
and pump power level. The slope and end points of the boiler
temperature vs the environment temperatures can be varied as well.

The controller behaviour can be logged to a PC so I can look at the
temperatures and power levels over a period of time.

Is this a system sold with the boiler or something bought or developed
separately?

Just curious!


Michael Chare