Check heating thermostat
If the radiator does not warm despite venting, this may also be due to a clamping thermostat.
Checking a heating thermostat in three steps:
- Remove the thermostat (knob) (step 1)by loosening the union nut. These are best turned counterclockwise with the aid of a pipe wrench.
- Now you can recognize the valve. This is a valve spindle (small chrome pin). Usually, the spindle should protrude about 5 millimeters and be easily pressed in by pressure.
- If the spindle gets stuck, this is probably the reason why the heater does not get warm. Release spindle (step 2)by now with a screwdriver lightly hit the entire valve body. If the spindle continues to grip, then lightly beat the spindle pin with the screwdriver.
- If the spindle is solved, that can Thermostat to be reattached (step 3), To do this, press the knob from the front against the spindle pin and screw on the union nut again.
