A gas turbine engine comprises a compressor rotor including blades and a disk, with a bore defined radially inwardly of the disk, and a combustor. A tap directs the products of combustion first to a valve and then into the bore of the disk. At least two temperature sensors sense a temperature of the products of combustion downstream of the valve. A control compares sensed temperatures from the at least two temperature sensors to ensure the at least two temperature sensors are functioning properly. The sensed temperatures are utilized to control the valve. A method of operating a gas turbine engine is also disclosed.