UTICA BOILERS UB90-200 Installation, Operation & Maintenance Manual page 27

Adjustments and checkout
It is important that this appliance operate between 8.5 And 10% co2. To verify that the appliance is
operating in this range, follow the steps below.
Important: under all conditions co levels should not exceed 100ppm.
Check incoming gas pressure to the appliance using a pressure gauge with a resolution of 0.1" w.c.
1.
Or better and a range from 0" to at least 14" w.c. Close the gas shut-off inside the boiler jacket.
Locate the inlet pressure tap on the gas valve (see fi gure 15). Open the inlet pressure tap screw
½ turn and connect the positive side of the pressure gauge to the inlet pressure tap. Open the gas
shut-off. The gas pressure should read between 4" and 10" w.C. For natural gas and between 10"
and 14" w.c. For propane gas.
Drill a hole in the plastic CPVC combustion analyzer.
2.
Turn the thermostat to the closed position so the appliance is activated.
3.
Allow the appliance to run for approximately 5 minutes.
4.
Insert the sample probe of your combustion analyzer into the hole you drilled in step 2 above, about
5.
halfway into the exhaust gas stream. Take a fl ue gas reading and observe the co2 value. Adjust
the throttle screw until the co2 value is between 8.5 And 10%. (O2 between 5.5% And 2%) turning
the throttle screw counterclockwise increases the rate and the co2 value. Turning the throttle screw
clockwise decreases the rate and the co2 value. Allow the appliance to stabilize for approximately 1
minute after adjusting the throttle screw before you take a reading with your combustion analyzer.
After adjustments are made stop the appliance, disconnect the pressure gauge, tighten the inlet
6.
pressure tap on the gas valve, remove the co2 meter from the cpvc pipe, and seal the hole with an
appropriate material.
Return the thermostat switch to its original position.
7.
Final checkout of the installation
After any adjustment to the appliance, observe several complete cycles to ensure that all components
function correctly.
Set Thermostat To Desired Temperature
Set thermostat to desired room temperature and observe
several complete cycles to verify proper operation.
CHECKOUT PROCEDURE & ADJUSTMENTS
NOTICE
Final Review And Sign-Off
Review all instructions shipped with this boiler with owner
or maintenance person. Instructions must be affi xed on or
adjacent to the boiler. Then complete and sign "Installation
and Checkout Certifi cate" at the end of this manual.
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