Heater not blowing hot

[Mudslutk51984]

my heater blows warm but not at all as warm as it should.. the heat picks up a bit while accelerating but doesn’t get very warm. The gate is closed and everything is in the position that is conducive to a heater making me think maybe a part is wore out.... ideas? Any parts schematic

 

[Fordum]

First thing, check your coolant level in the radiator. Low coolant will cause that.

 

[tRustyK5]

Thermostat stuck open or missing will also cause poor heat.

 

[Chevman88]

In addition to the above, when is the last time you did a coolant flush?

 

[imiceman44]

All of the above
My guess since it's warm and gets hotter when you accelerate it must be a stuck or missing thermostat

 

[Mudslutk51984]

I just had to change the water pump so I filled it recently. Flushed it too. It’s been this way for awhile. No leaking core no obvious failure signs.

 

[diesel4me]

As noted,the thermostat is what keeps the engine coolant at the desired temperature--I use only 195 degree thermostats,that is what GM has used since 1968...here in MA you need all the heat you can get--some frigid days I put a piece of cardboard in front of the radiator--I have a vinyl grille cover that came with my diesel suburban you can put over the grille to get more heat in the most frigid weather..

Heater core is likely clogging up with deposits,if all else checks out good --if anyone ever put radiator sealer in the radiator it is a good bet most of it went in the heater core and stayed there..often a good flushing with a garden hose with decent pressure will get rid of most of the restriction and improve the heaters output..you do risk making it leak though,especially if you have too much pressure,so only flush it with a hose nozzle that lets you control the pressure and flow..