Ask a heating pro about the energy used by the systems they design or install. Their response is almost guaranteed to deal with “fuel” energy (e.g., natural gas, propane, oil, pellets, etc.) required by their systems.
With the exception of systems with electrical boilers or heat pumps as their primary heat source, few heating pros give much thought to the electrical energy used in their systems. Perhaps they view such energy as trivial in comparison to fuel energy. They might regard it as simply a “parasitic” necessity for delivering heat produced by the high efficiency heat sources they specify or install.