Heater does blow hot air

[melhilburn]

I have a 1964 c10 with a 292 inline 6 - When I run my heater the air gets luke warm - Any idea what the problem could be?

[markeb01]

Here are the things I’d check:

1. If you have a hot water valve in the system it may not be opening fully.
2. The heater core could be plugged not allowing much hot coolant to flow through.
3. The ducting could be full of crud, blocking the air flow.
4. The engine thermostat may be shot or too low a temperature, not generating enough heat from the engine.

[melhilburn]

Thank you for the help - I'll go through the system step by step - Question- If I find that the core is plugged what do I have to get a new one or can it be flushed out? - Also would you know what the correct engine thermostat should be?

[1963c-10]

180 should be the standard thermostat. You can try and flush it out (easier to do once removed. A new core will be your alternative if unable to flush.

[luvbowties]

Originally Posted by melhilburn

Thank you for the help - I'll go through the system step by step - Question- If I find that the core is plugged what do I have to get a new one or can it be flushed out? - Also would you know what the correct engine thermostat should be?

...and cost of a new one is only around $34...see AutoZone and Advance A/P

[melhilburn]

Looks like the previous owner removed the main thermostat - I install a new 180 thermo and presto the heater works like a charm - thanks for the help!