What would cause coolant to run out very quickly in a VW Golf?

I have checked for leaks which i cannot find any sign of and the temperature dial is normal. I have been told its because I have the in car heater on more because of the winter temperatures but I have had to top it up twice in about 3 weeks and that doesn't seem right. Should I get it checked out at my local garage?What would cause coolant to run out very quickly in a VW Golf?Bad hose, leak in heater core ,leak in radiator, water pump has weep hole if seals go bad in pump weep hole will leak.Also your head gasket can be blown and it could go two ways in the oil jacket or in the combustion chamber so , in the oil it will make your oil look milky if it went into the combustion chamber it will go out the exhaust and cause steam out your tail pipe. but if you have to keep adding coolant i would take it in and have it checked.What would cause coolant to run out very quickly in a VW Golf?
"i have been told" by who? cars cooling system is closed..unless its leaking it or burning it level should not go down...

1 get garage to do "leak down" test...puts pressure on system to see if it holds pressure

2 check oil for signs of coolant/water...brown foamy mud.What would cause coolant to run out very quickly in a VW Golf?if you have checked for leaks and havent found any then check your passenger side floor under the dash. if it feels damp, soggy, or smells like mildew then your heater core is leaking. easy diagnosis.
Make sure you are using the correct fluid, and you get 4-5 different types/colors.

Another thing to do, just to make sure for definite that there is no leak, is to use a product called K-Seal. amazing stuffWhat would cause coolant to run out very quickly in a VW Golf?Well double check for leaks ,, but one reason could be a blown head gasket causing coolant to enter engine cylinders and be heated and is steam in exhaust . Even worse could be a cracked engine blockWhat would cause coolant to run out very quickly in a VW Golf?
Ask the garage. They can pressure-test the system to find leaks that aren't apparent with the engine off.
The car does not use more water because the heater is used. It is normally a closed sealed system. If there are no leaks you have a blown head gasket.What would cause coolant to run out very quickly in a VW Golf?
it sounds like you could have whats called a perforated hose where you cannot see the leak as it leake s under pressure
as well as all the above it could be a leaking water pump, when the engine get hot, but not leaking when cold.
your dealership has the answer. I would ask them. it might be cheaper than a newer car
are you sure its not finding its own level,it depends how much your having to put in