Icos : No Central Heating / Hot water OK
Icos : No Hot water / Heating OK
This is not a boiler fault
If either heating or hot water (not being heated by immersion heater, check turned off) is working OK, this proves boiler is working OK (Boiler cannot differentiate between heating and hot water modes). Therefore lack of heating or hot water is system related fault, suggest check Programmer & room thermostat (no heating) or Cylinder thermostat (no hot water) or recall installer.