Checking Gas Input Rate To Boiler - UTICA BOILERS MGB-50J Installation, Operation & Maintenance Manual

• Adjust gas input to boiler by removing protective cap on
pressure regulator and turning screw clockwise
,
increase input and counterclockwise
input.
• Manifold pressures are taken at outlet side of gas
valve.
• To check for proper fl ow of natural gas to boiler, divide
input rate shown on rating plate by heating value of
gas obtained from local gas company. This determines
number of cubic feet of gas required per hour.
• With all other gas appliances off, determine fl ow of gas
through meter for two minutes and multiply by 30 to
get hourly rate.
• Make minor adjustments to gas input as described
above. See Figure 16 page 18.
• Change burner orifi ces if fi nal manifold pressure
varies more than plus or minus 0.3 inches water
column from specifi ed pressure listed on boiler
rating plate.
• Primary air adjustment is not necessary, therefore
air shutters are not furnished as standard
equipment.
CHECK SAFETY CONTROL CIRCUIT. Test ignition
system safety shutoff device after placing boiler in
operation. Figure 15 page 19.
Intermittent Pilot: With main burner operating, turn
1.
pilot gas adjusting screw clockwise
gas is turned off. Within 90 seconds main gas control
closes, shutting off gas to main burner.
High Limit Control: Remove plastic cover and
2.
note temperature setting. Refer to appendix A for
adjustment procedure. Decrease setting to minimum
and operate boiler. When boiler water temperature
exceeds control temperature setting, control will open
circuit, closing automatic main gas valve. Figure 21.

14 - CHECKING GAS INPUT RATE TO BOILER

to
to decrease
until pilot
Figure 21 - High Limit Control Location
High Limit and a a nd n d n n n n n nd nd
Operating Control o o nt nt nt tr tr t r t t t t ol ol ol ol l l l
Burner Access r r Ac A A c Ac Ac Ac ces ces ces ce ce es s s s
Door oo oo o r r r
22
Gas Valve