Since no two types of wood – and treatment of the wood – are the same, there is no single answer as to whether you can use a patio heater on a wooden veranda. The important thing is that the surface to which the patio heater is mounted is able to withstand at least 100 degrees Celsius. Whether this is so for your veranda will have to be checked with the seller of the veranda. Be on the safe side and inquire before installing the patio heater.
In addition, when installing a patio heater, you should always take into account the minimum distances from the ground, wall and ceiling. These distances can be found in the instruction booklet of your patio heater.