ideal icos 15

Morning, I have an ICOS IDEAL HE15 boiler with a seperate water tank upstairs. I'm having a few problems with my Hive install (attempted by myself). When I click the CH button on the receiver it doesn't fire the boiler up however, if I click the HW button it does. I removed my thermostat from...

As my hot water is from solar I only need the 'central heating' on. But now I find the boiler will only fire up and the central heating work if the 'domestic hot water' is turned on too. It has been fine before but now when I need heating on more it refuses to fire up unless the hot water is...