I didn't say solder the contacts together.

I said solder the connectors together as in bond the connectors permanently to the thermostat after cleaning them up.

 

tcmtech, sorry I misread that.
Anyway, the problem has been found.
It was indeed low output of the fan.

In frustration, I put a small fan behind the heater, blowing more air into the intake vents.
That worked, and the heater has been working well for about 3 hours straight.

It's a good thing too, because it is very cold today.

The motor appeared to be doing the job, but it was weak.

Thanks,
Gary

 

Both? I know there is optimum for machining aluminum, but you have to be spot on to prevent melting and welding of the chips, but often the exact grade/conditions of the material are not known, (I am not a machinist!).
In a pinch Kerosene is almost as good.
Max.

Kerosine is a standard coolant/lubricant stocked by machine shops - I can't remember what metal its to be used with, could well be aluminium.

 

Kerosine is a standard coolant/lubricant stocked by machine shops - I can't remember what metal its to be used with, could well be aluminium.

Aluminum is what I use it for, when I don't have WD40, I have a CNC mill and Lathe I use for custom one-off items.
Max.