There may have been some water left in the heater core when you disconnected both hoses at the firewall. I can't think of any other explanation since there is no water circulating through the heater core.
the heater core, heater core hoses or heater control valve is leaking
If they disconnected the heater core, it means it was leaking. Get a manual on your car from the parts store and it will show you how to replace the heater core also
If it is leaking inside the car, the heater core has failed.If it is leaking inside the car, the heater core has failed.
roof or heater core leaking roof or heater core leaking
A leaking heater core will cause the engine to overheat because the coolant is leaking out.
Leaking heater core.Leaking heater core.
The heater core is leaking. Replacing the heater core is your best bet.
did the heater core start leaking? anyway you should have no problem with the air if you bypass the heater core.
The only fix for a leaking heater core is to replace it.
No, a clogged heater core will not make it overheat. A leaking heater core will.
Your heater core is leaking, Need to REPLACE HEATER CORE.
The only fix for a leaking heater core is to replace it.