Every few days I get this warning on the dash. The original coolant bottle was still fitted and the sensor prongs were covered in scale so I cleaned them. This didn't sort the issue so I replaced the coolant bottle with a new one. Every few days I get the warning but the level hasn't dropped.

To clear the dash warning all I need to do is remove/refit the cap and the waning dissappears once the bonnet is shut, I'm sat in the seat and the door is closed.

Is there any issues with wiring etc that I should be checking next?

Maybe the connector to tank is needing cleaned or there is a break in wire.

Alasdair

If the cooling system is being pressuried by gas from say a leaking head gasket,the increased pressure will force expansion of the rubber hoses and reduce the coolant level. This will expose the fangs and give low coolant warning.

Next time it happens, stop and immediately check the coolant level by looking at the side of the container. Then either carefully release the pressure cap or wait and see if the level rises as it cools down.

You could also try another pressure cap in case is not releasing as it should.