Your heating is working, but you have no hot water. If you live in a building with multiple tenants in and you share the use of the boiler, it may be that the tank is empty because others have used the shower before you.
If the above is not the case, you need to reset the boiler. You can do this in various ways:
Afterwards you can restart the boiler. Check the heater, it could be that the adjustment knob is accidentally twisted. Put it on the highest setting.
If the above doesn’t resolve the problem, we advise you to check the shower or the hot water tap. Is there a lot of lime scale on it? This may be the reason that you don’t have hot water. A calcified showerhead or aerator gives too much back pressure to the heater whereby it doesn’t start.
Descaling is the responsibility of the tenant. You can buy a descaling product from any good supermarket or a hardware store.
If you don't have hot water and your heaters are failing as well, please make sure that your central heating boiler is working properly.