You may have a boiler which heats your water only.
If you have a central heating system, it is likely that you will have a combi-boiler which controls water and heat.
If this stops working, report it to your landlord ASAP.
If you have a hot water boiler, this might be found in a separate cupboard. A combi-boiler might be located in the kitchen.
When you view the house, make sureyou are clear what type of boiler you have and where it is located.