Extruder not heating when connected to Repetier Host

[malp]

I haven't used my printer for a few months. I tried to do a small print from Repetier Host but the extruder does not heat up and the red LED does not light. If I close Repetier Host the red LED lights up and the extruder heats up.

[_kaktus_]

Being in your place, I would check carefully the configuration of the program.

[Gingko]

[quote=malp post_id=84323 time=1527343581 user_id=55818]
I haven't used my printer for a few months. I tried to do a small print from Repetier Host but the extruder does not heat up and the red LED does not light. If I close Repetier Host the red LED lights up and the extruder heats up.
[/quote]

Hi, malp
If setting the extruder temp directly by LCD, will it heat up normally?