Biasi - Activ A combi boiler hot water query

[sjhayes2010]

What's the point / advanatge of having both a DHW flow switch and a 3 way diverter valve on this combi? I just wondered while looking through the manual - I have known some to use both - but just wondered what the point/advantage was really?

 

[transam]

Hw flow switch on mains (in) signals a demand to the boiler that a tap is open , there fore fire up , otherwise how would the boiler know ? divertor valve diverts around plate exchanger or rads for heating ,dependant on the signal it gets !

 

[sjhayes2010]

Thanks for your reply mate

I know how it works but usually you have a flow switch (direct hw) or a plate heat ex. and diverter valve - but what's the advantage of having both?!

 

[transam]

Ok so take the dhw flow switch or flow sensor out of the equation ? on any combi ?

How would the boiler know a hot water demand was being made ( tap open )

 

[sjhayes2010]

i know how it fires up but usually with a diverter there's a microswitch that it trips - just wondered why this boiler had both a DHW flow switch AND a diverter valve!

 

[transam]

If u know how it fires up , than u know that the boiler must sense a demand being made on it ? a flow switch on the mains entering the boiler tells the boiler to fire for HW , because it will only operate via flow of water which = a tap open ! This is not unique to a baisi activa

 

[sjhayes2010]

Some combis use a flow switch to activae the igniotion for hw (direct combi and no dhw heat ex) or a lot use a diverter valve (and microswitch) with a plate heat exchanger to heat up the hot water (indirect) - but this one uses both - my query was why? or what's the advanatge!

 

[transam]

I will leave it to some one else .

 

[sjhayes2010]

ok thanks for your help and time mate.