Hi, I have recently moved into a 3 story terraced house built in 2011. When I moved in, the house utilised a danfoss heating system that I wasnt familiar with. Inside the airing cupboard (which is situated on the top floor) was a danfoss FP715 Si 2 channel programmer for heating and hot water. On the wall outside of the airing cupboard was a TP5000 Si thermostat. On the ground floor there is a simple danfoss dial to set the temperature. This setup seemed to work ok heating the house and controlling the hot water. My problems arose when I decided I wanted to upgrade from a fixed programmer to a newer app controlled system. I removed the FP715 inside the airing cupboard and replaced it with a drayton wiser (kit 2), whilst also removing the batteries from the TP5000 and capping its electrical cables with electrical tape to render the thermostat inert. Both the drayton wiser and the original danfoss FP715 both seemingly had the exact same terminal connections so I thought this would be a straight sway. Once I made this change however, I lost the ability to control the heating to the upstairs of the property. The hot water and downstairs heating continued to work fine. Eventually, I realised that the airing cupboard contains 2 danfoss HPA2 valves. Im guessing 1 controls the upstairs and 1 controls the downstairs as when I engage the manual override on one of these, the upstairs heating magically works. My query is essentially 2 fold: 1) can a drayton wiser smart programmer work in the system I described? The original programmer seems to suggest that the property is a 2 channel system (channel 1 central heating, channel 2 hot water), however if there are 2 HPA2 valves, doesnt this suggest a 3 channel system? 2) if it is only a 2 channel system (which I hope is the case), how can I get the drayton wiser to open up the second HPA2 valve automatically? Ive read that these automatic valves fail sometimes and need replacing but before I do that, I want confirmation that its likely broken and simply replacing it will fix the problem. I have attached a picture of my airing cupboard in case that offers any insight into my system. Thanks for your input in advance!