steam pressure problems to steam coils

JDill4207

good afternoon I'm running a burnham steam boiler gas fired pushing 1.2 mil btus the problem I'm having is i have 3 air handlers with steam coils on the roof of this building every time i turn on air handlers i loose steam pressure when i turn the blowers off my steam pressure comes back i replace the steam traps removed the coils and cleaned them inside and out and I'm still having the same problem I'm pushing about 6 psi of steam to the roof does know what the problem could be

EBEBRATT-Ed

So the problem is the boiler will not produce enough steam for all the air handlers to run....when the fans run you losing pressure correct??

Clock the gas meter to check the burner firing rate.

Are the outside air dampers on the air handlers stuck wide open and they shouldn't be?

The burner is firing but is it running on high fire?

Is the burner two stage or modulating?

Any steam valve or control valve between the boiler and the AHUs not fully open??

What is the water level in the boiler doing? Is it steady?

Are you feeding excessive cold make up water into the boiler?

Just one boiler in this system?