Heating Problem

[sceptre]

I went out to start my truck yesterday morning and it was only a degree or two above freezing so I figured I'd let it run for a bit....so I set my air to the front window and set the temp to 22 degC. I went back out some time later and the engine temp was up to normal operating temperature but my front window was frosted up on the inside. I turned the heat up to 30 degC and it immediately became hot.

 

I went out this morning, same thing....few degrees above freezing but today I didn't have time to let the truck idle for very long. I set the controls to front defrost again and temp at 25 degC. The temp hand was up to about 1/8 of the guage so I pulled it in drive and idled down my street. By the end of my street the guage was at approx 1/4 but the air blowing out was still FREEZING cold. Truck reached running temp (1/2 on guage) and the air was still ice cold coming out of the vents. Then all of a sudden it got really warm, like it should have. I would think that it should have gradually gotten warmed as the truck warmed up.

 

I've got a 2006 v-max with the digital hvac controls. Does this have something to do with not throwing engine heat right away?

 

Any info would be great.

 

 

 

Nick

[sceptre]

i guess simply put...should the vents be throwing heat while the truck is warming up?? or do they not produce heat until the engine is at operating temp??

[minibike132]

If the engine is not hot it can not put out hot air.

[C6Racer]

The heater will not gradually get warmer as the engine warms up. There is a device in the cooling system called a thermostat. This device is designed to START opening at around 190 degrees F(about 88 degrees C) of coolant temp. This means that, until the thermostat starts opening, there will be no coolant flow through the radiator or heater core. The heater core is a mini-radiator inside the passenger compartment through which air is blown to heat it up.

[1500CCZ71]

I have a 04 Silverado with a 5.3 L engine that has heater problems similar to sceptre's problems(my heater however is the standard heater, not the digital set point controlled heater). The heater has worked fine for years but now seems to be prone to blowing cold air. I have found that after a normal warm up period the heater is blowing cold air. After a few more minutes there is some warm air but it turns quickly back to cold if I increase the fan speed to high. After running the truck for 45 minutes to an hour, there seems to be no heat issues. This seems to indicate a flow issue of coolant into the heater core. Are there any thoughts on the fix for this?

[95Sierra2500]

Woah. FYI, coolant WILL flow through the heater core while the thermostat is shut. Why do you think you start getting warm air (or at least I do in every vehicle I've ever driven) just after the needle starts to move? It's not because the thermostat opened. There just isn't enough surface area for the small amount of cooling to be noticed.

 

As for the OP's problem, I would guess you have some form of blockage in your heater lines/heater core. What it could be I wouldn't guess. A coolant system flush may help though.

[98silvz71]

Make sure that you have the right mix of coolant. If you have too much water it could be freezing and then when the engine gets warm enough it could melt and voila there is your heat. I'm not talking like a 60/40 mix thats off. I'm saying like make sure its not a 90 water/10 antifreeze mix. You never know.

[yukon_denali_05]

I have an 05 yukon denali and my front heat is working fine and blowing warm air. But the rear air is blowing bold instead of heat. Its digital controls. What can this be? I had a remotely start installed yesterday and it only started after the install. What could be the problem?