HiCustomer welcome to Just Answer!.
You've probably got codes set that are a result of cooling system issues, which would translate to your heater problem if coolant levels are low or the thermostat
is flowing all the time.
Check the coolant pressure bottle underhood to see if your level is within the normal range first off. I'm thinking you may see nothing in the bottle...
If low, at least add a 50/50 mix of coolant and water before driving again unless temperatures are expected to be mild for the amount of time it would take to get the car into the shop to find out where coolant is disappearing. Moderate temps mean you can get away with straight water in the bottle as an emergency measure, but it can't be driven long like that. Watch for rapid coolant loss from beneath the vehicle when coolant is added, which will tell you if the car can be driven or needs to be towed to the repair facility.
You can check your codes by rolling the key from off to on three times and leaving the key ON, with code display showing up in the odometer window of the instrument cluster. The driver's door needs to be shut for this by the way...
Our late model vehicles don't always display ALL the codes they should for some reason, so this wouldn't be the last word on what codes are stored with the car... that's what code scans will do.
The last thing shown will be "done" when the code-read feature successfully ran, something that can take several attempts before it works. Try cycling the key faster... slower... even turning the key all the way back to the LOCK position each time.
So check your coolant level and then try the code-read feature. Let me know what you find.