Because I have zone A (downstairs) and zone B, (bedrooms upstairs), only one zone, at any one time, operates effectively. Also that roof-mounted '-solar powered whirly bird which is ineffective so far as I know....most of my day is downstairs so just use the downstair zone....it's always close to an oven upstairs but fortunately have a bedroom downstairs.... four bedrooms here of which I use but two as bedrooms....3 of these rooms are very small....
