The heater takes a long time to warm up

check heater plugs ,it will take around 20 second if heater plug is
not working one or more it will take 10 second . you can S.W ON and off many time so. the engine warm.then try to start

Bad news ,nothiong worse than a cold car so iam assuming this is a 16v job and the thermostat is behind the timing belt which is a summers day type job ,so as a temporary fix put a sheet of cardboard in front of the rad till the weather warms up this will make the engine run hotter and the cars internel heater radiator will be all the cooling it needs in the cold weather

That seems pretty normal, the heater works by blowing excess heat from the engine coolant. So the coolant has to be warmed completely for the heat to work, you can get a heater that plugs into your cigarette lighter that will heat the vehicle instantly.

Does it take a long time to warm up the engine?

Could be one of several things. Your car has automatic climate control that takes air temp and coolant temp into consideration in controlling the heater components.
The heater blower will not come on until the heater warms up. So the engine thermostat could be faulty and the engine is taking a longer time to warm up.
The electronic controller adjusts blower speed. And the blower motor could be going bad.
You may have to get a shop to take a look at it - someone with the books and tools to test the system.

try cheking the timing of the engine

low fluid level or heater control valve may need replace..check hoses going to heater core...if cold...between heater control valve and heater core..replace control valve

1st thing I would do is have your thermostat checked at a rebutable rad shop also somtimes the rad cores get blocked and will not circulate the heat properly either problem can be rectified at the rad shop...good luck

check the thermostat it is most likely stuck open. bobg33

a couple likely causes:
1: the engines thermostat is stuck open preventing the engine from warming up quickly. If the engine temps read normal (warm) but the heater is still cool, then....
2. the Heater control valve (a valve that prevent hot water flow when you dont want it), may be clogged or malfunctioning. this is typically located on the heater hoses between engine and firewall.