So this morning it took about 40 minutes from the heating turned on to go from 17 degrees to 19 degrees. Is that about right?
If it is a more control system, controlling a modern boiler, and the demand for heat is minimal - then the radiators do not need to get that hot, and may only get warm at the upper part. It all depends on the demand for heat.
If you want to properly test the system, wack the room stat up to max, along with any TRV's, the radiators should then get really hot, top to bottom.
