Changing the thermo-hygro sensor in a Helios weather station.

Bring the vane down from its mount, and remove the battery
Place the vane upside down with the wind instruments hung over the end of the bench/table (for protection)
Take the permitter screws out of the base of the vane
Unplug the wind instruments from the ‘top’ of the vane – this makes it easier to work with the bottom only
Remove the Stevenson house (louvers) from the bottom of the vane

This next step can be tricky - please take time and care with removing the hot glue

Lift the main board cover up and unplug the thermo-hygro sensor (follow the wire from the thermo-hygro back to the cover to determine the correct plug)
The plug can be worked back through the cover, releasing the cables
Carefully remove the hot glue from the top of the thermo-hygro sensor
Using a small blunt object push the thermo-hygro down through the cable hole (i.e as if from inside the vane, pushing the chip out the base)

I recommend pushing towards the middle, taking care not to force it, several small pushes will see it loosen and then it should pop out

With the thermo-hygro free, pull the sensor out of the base of the vane with its plug and cable
Push the new plug through to the vane from the base (i.e working from the outside in)
Gently pull the cable through and push the new thermo-hygro onto the ‘stalks’ – there’s no hardware, this is a press fit item
Use a piece of duct tape to re-cover the cable hole entry
Push the plug through the main board cover, and plug it in
Put the battery back into the vane
Temperature readings should resume immediately - monitor over the first 24hrs
Screw down the main board cover again, duct tape over the cable hole if you feel inclined, then plug the wind instruments back in.

Screw the 2 sides of the vane back together and it’s good to go.

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