❄️ With the influx of cold days these past 3-4 weeks, the heater calls are rolling in. If your cabin is stuck on cold, here's what I'm checking first before we dive deeper.
🔥 Usual suspects: a heater core clogged with old coolant, blend doors or actuators stuck, a heater control valve that won't open, thermostats stuck open or broken, low coolant from slow leaks, a tired HVAC fan, and coolant so dirty it can barely move heat.
🧪 Quick driveway checks: confirm the engine actually reaches temp, make sure both heater hoses feel warm (a cold return hose points to flow issues), listen for blend doors moving as you change temp/defrost modes, and look for low coolant or oily residue in the reservoir.
🚗 Shop update while it's chilly: I'm wrapping up the GMC transmission job after a parts delay, diagnosing another no-start Power Stroke, and the 2008 Ford F250 will be coming in for oil leak repairs.
👨🔧 If the heater core's plugged or the valve is frozen up, we can flush the cooling system, swap the stuck components, and get the vents blowing hot again without guesswork.
Quick tips
- Top off with the correct coolant mix and burp the system after any cooling service so air pockets don't block the core.
- Don't ignore a cold gauge on the dash — a thermostat stuck open keeps the engine and cabin from ever warming up.
- If you're smelling coolant inside or seeing fogged windows, schedule the visit before a minor seep becomes a full heater core failure.