What controls the hot air?

[General Zod]

Apologies for the noob question--I'm still learning about cars in general, and Z-3s in particular--but I'm having an issue with my heater (i.e. my hot air conditioning).

It's not consistent: sometimes it heats up like it's supposed to, and sometimes it doesn't.

I'm wondering why that is?

What controls the heater? How does the air conditioning get hot when you turn it to the hot setting?

Thanks!

 

[Richardrix]

I believe it could be the thermostat causing your issue. Does the engine temperature gauge get up to the middle quickly or does it linger around the colder end. If it lingers then you shoudl change the thermostat. I have had this on a couple of BMW and most recently on my Z3 1.9. Once I changed the thermostat the heater controls would work reliably. I hope this helps.

 

[General Zod]

I believe it could be the thermostat causing your issue. Does the engine temperature gauge get up to the middle quickly or does it linger around the colder end. If it lingers then you shoudl change the thermostat. I have had this on a couple of BMW and most recently on my Z3 1.9. Once I changed the thermostat the heater controls would work reliably. I hope this helps.

It does linger around the colder end.

Thanks for the tip! I will check the thermostat.

 

[Z Victor 1]

Had the same problem with my first Z3 when I got it and it was the thermostat.

 

[jonco]

As others have said check engine stat first, which seems likely cause given gauge indication. If you change it see various threads on bleeding system which can be a pain if not done correctly.
If problem still exists, the actual heater valve is located at rear of engine compartment near side - you can do touch tests on in and out hoses to give an idea if there is a problem here.

 

[Bampz]

If you need to change the thermostat it is probably worth changing the water pump at the same time as a preventative measure unless you know the cars history and it's been changed already

 

[Z Victor 1]

Belts and pulley wheel too.

 

[Nodzed]

What controls the heater? How does the air conditioning get hot when you turn it to the hot setting?

If the AC is on and the heater set to hot the result will be (and should be) hot dry (dehumidified) air perfect for demisting in the winter. Running the AC in the winter will help keep the inside of your Zed damp free if used with a hardtop on or soft top up. Obviously set to cold and you will get icy cold air as long as your AC system is working as it should. The Heat knob regulates the desired air temp regardless of whether the AC is on or not.

 

[General Zod]

The Heat knob regulates the desired air temp regardless of whether the AC is on or not.

Thank you: you've made me realize I misspoke when I said "A/C". I'm just talking about the hot air temp control.