"Jmagerl" wrote in message
...
The radiators are warm. All the valves are open. I hear no gurgling (air
in the system). I am thinking inadequate radiators but there is no room to
add any more.

Check that it is operating properly at the burner.

Raising the temperature may help if the heater is cycling off and on. If it
never shuts off, that means it does not have enough power to heat the house.
If cycling, raise the temperature 10 degrees. If not, insulate and/or buy a
bigger heater.