Posted on 11/28/2025
A heater that stays cold while the temperature gauge looks fine is frustrating. It usually means coolant is not reaching the heater core, hot air is not being directed through it, or the system is being fooled by a sensor or control fault. Here is a clear path to the most likely causes and the simple checks that separate them. What “Normal Gauge, No Heat” Usually Means Your dash gauge reports engine temperature at the sensor near the thermostat, not the temperature inside the heater core. If coolant is low, air can collect in the heater circuit and block flow there while the engine itself still reaches normal temperature. Another common pattern is a stuck HVAC blend door that never routes cabin air across the hot core. Less often, a partially restricted heater core flows just enough to warm the firewall but not enough to heat the cabin at idle. Coolant Level and Air Pockets: Quick First Checks Only check when the engine is completely ... read more