Using plus in expression in combination with a sensor value doesn't work

[c7pher]

case: [Weatherstation : dewpoint] + 1 (with dewpoint set to 13) = 131

using a double negative works: [Weatherstation : dewpoint] - (-1) = 14

Also dividing and multiplying work as intended.

[c7pher]

using the offset 1 as a variable is ignored completly, either wich calculation I try

[idpaterson]

That value might be coming out of your device handler as a string. One way to handle that is to use int([Weatherstation : dewpoint]) + 1 to convert it to a number.

[c7pher]

confirmed working