Pilot Adjustment - RBI FUTERA XLF Series Installation And Operation Instructions Manual

Pilot adjustment

1. The pilot pressure has been factory set at 3 inches w.c., and
shouldn't need adjustment.
a. With the boiler powered, generate a call for heat.
b. When the prepurge is complete the ignition/pilot trial will
begin.
2. To adjust the pilot the following steps must be taken:
a. Put the Honeywell RM7800 test switch in the test position.
Th e control will hold in the ignition/pilot sequence, allowing
you to check the pressure.
b. Connect one side of a manometer or pressure gauge to the
manometer pressure port (barbed) on the pressure test
manifold (located inside control panel). See fi gure 18. Leave
the other side of the manometer open to the room. DO NOT
connect it to the reference port (left side of panel).
c. Measure pilot gas pressure by pressing and holding the
service valve marked PILOT GAS.
d. Set pilot gas pressure to 3.0 inches w.c. (± 0.5 inch) by
adjusting the pilot gas pressure regulator, inside the air box.
Access from the boiler top cover. See Figure 19.
e. Check pilot air pressure using service valve marked PILOT
AIR.
f. Pilot air pressure should be 0.60 inches w.c. (± 0.10 inches).
Never force the regulator adjustment screw beyond the
stop limits or damage to the regulator will occur!
Required gas pressure
Provide gas supply pressure at inlet to boiler gas train as follows:
Gas supply pressure (Nat/LP)
water column
Minimum (in W.C.)
Maximum (in W.C.)
1. Measure pressure when the boiler is firing at full rate. Low
gas pressure could indicate undersized gas line or insuffi cient
gas supply.
2. Static and operating gas pressure required at the gas valve inlet is
listed in the Table above.
F F Finned copper tube gas boilers & water heaters – Boiler Manual F d
Inches mm
water column
3.5 88.9
14 356
b b l & h
If the gas pressure is above the limit in the table below,
a lock-up style gas pressure regulator suitable for dead-
end service, (such as an Equimeter or Fisher) must be
installed to prevent increase (creep) of gas pressure
when the units are not operating.
This pressure regulator (supplied by others) may
be installed at the service entrance to each unit or
a "master" regulator sized to handle multiple units
may be utilized. Consult local gas utility or regulator
manufacturer for recommendations to meet specifi c
job site requirements.
Input rate — Natural gas
Gas appliances are rated based on sea level operation with
no adjustment required at elevations up to 2000 ft, 610 m.
At elevations above 2000 ft, 610 m input ratings should
be reduced by 4% for each 1000 ft , 305 m.
Check the input rate as follows:
1. Turn off all other gas appliances that use the same gas meter as
the boiler/water heater.
2. Call your gas supplier and ask for the heating value
of the gas.
3. Start the boiler/water heater and let it run for 15 minutes.
4. Using the gas meter and a stopwatch, clock the time that it takes
3
to burn 10 ft , 0.28 m
5. Insert the heating value and the time, in seconds, into the formula
below.
6. Input = (heating value, Btu/hr)(3600)/(time, seconds)
7. If the computed rate deviates by more than 5% from the rated
input value of the unit, consult factory.
Never increase the input to the boiler/water heater
above that for which it is rated. Doing so can cause
premature failure of the boiler!
B l M l
3
of gas and divide this time by 10.
29