Hi,
Has there been any recent repairs on the system ?
There could be a couple of different problems here,
1.) You may have air in the system.
2.) Your The front of the house may be on a different zone that the zone controls aren't working on. How many thermostats do you have ?
Thank you
Mark.
Journeyman Technician
UA Journeyman Pipefitter , HVAC, Refrigeration, DDC controls. 26 years.Commercial & residential
The oil shouldn't be the problem it sounds like you need to bleed the water system of air whereas you may have had to have bled the oil line last time. Two different things.
If you pull the covers off of the baseboards that aren't working you should find a bleed valve on at lest one of them ? Have you ever done this before ?