Need help with todays inspection

Todays inspection was a duplex with 2 boilers and 2 hot water tanks. All natuaral gas. Each water heater exhust vent was connected to the vent for the boiler and all 4 were vented into a single flue chimney with no liner.

House was built in the late 1800s.

Note the pressure relif valve.

In the last picture this is a vent for the boiler, notice the deterioration in the pipe, directly opposite from these hole’s is where the vent for the water heater is connected.

I would definitely write up the unlined chimney and suggest a level 2 inspection and calculations on the proper sizing for the number of vents using it.


Thanks Anatol; does anyone have the code for venting multiple gas units?

High potential for back-drafting, refer it to the HVAC technician.
I would also recommend having HVAC tech calculate combustion air needs. That many appliances burn a lot of air.
From those pictures I bet they will be doing some repairs!