One of heating pipes bursted.
Replaced pipe and all is sealed.
Gauge indicates no pressure temp reads 180
Disconnected pressure regulator and water comes out strong on outlet end.
Have heat circulating on most of the first floor.
No heat circulating to second floor.
Water feed is feed, pressure regulator, expansion tank with y fiiting, y fitting to air purge w
A air vent attached on top, t into boiler tank and main house feed.
Why is there no preesure and what to check?
Thank you

If you have zero pressure indicated by the gage, your auto-feeder is not working. Look for a small regulator on the cold water intake pipe coming from your domestic water supply to the boiler. Most auto-feeders look like an upside down ice cream cone with a small tail on top. Lift this tail, you should hear water entering into the system. Carefully watch your pressure gage to make sure it is rising. Do not put more than 20 pounds of water into the system otherwise the relief valve will spit out boiler water. Most likely you will need to purge the air out of your second floor zone. Once your system is up to pressure, get a technician in to replace the auto-feeder and purge your system.

Is auto feeder same as pressure regulator
It is a WATTS #3156 (an upside down cone with a lever on top
Lifted lever and hear no water entering system and still no pressure

Make sure all valves are open upstream to the Watts. If so, you need to replace the feeder.