"Andy Hall" wrote in message
...
On Sun, 19 Sep 2004 23:50:08 +0100, "IMM" wrote:


"Tom" wrote in message
...

Thanks Andy, would you agree that the Alpha might induce condensing
conditions in my standard boiler, assuming that thermostats and TRV are
susceptible to frequent adjustments in my household :-(

As long at the boiler is set to 80C this is highly unlikely when the
system
is warmed up.

You may require a minimum flow through the boiler. Then I would forget
the
Alpha a go for am open rad and room stat.


You can set the nominal power level on the Alpha above or below
nominal setting.

If all TRVs are close, no flow. It is best to get a flow switch rated at
the minum boiler flow. below this flow the boiler burner is cut out. The
pump can still pump through the boiler.

http://www.crydom.co.uk/
http://www.axdistribution.com/FluidM...ow_switchs.htm

Even so, I agree that if the existing pump is OK, it makes more sense
to try that first and only switch to an Alpha if there is a problem
with noise in the radiators closed down case (i.e. reduce pump
setting), but that that is not enough wit everything open.


.andy

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