getting very little heat

Could be that the heater core is bad/clogged...Also check the hoses going and coming from the heater core...

IYM

Have you ever had the cooling system flushed? Sometimes heavy crud settles to the bottom of the radiator and heater core and impedes flow. Feel the hoses from / to the heater core while the engine is hot, heat on full and fan on high. You should be able to feel a noticeable temperature difference between the inlet and outlet hose temperature - if not, heat is not being transferred from the core to air in which case it may be a problem with the air control door position.

Likely causes:

1. Low on Engine Coolant

1. Stuck heater valve (some vehicles have these near the firewall and stop flow to heater when set to cool or A/C is used)

1. Collapsed hose (can happen if old - no coolant flow)

2. Blocked heater Core

1. Defective/Failing Water Pump

Maybe the little knob that adjusts the temperature door is not moving the door all the way to hot. Fred