SPECTRUM INSTALLATION AND OPERATING INSTRUCTIONS
Page 22
CHECKING & ADJUSTMENTS
Pilot Adjustment
The pilot burner flame should envelope
3/8 in to 1/2 in
,
9.5 mm to 12.7 mm of the flame sensing probe, Figure
11. To adjust the pilot the following steps must be taken:
1. Remove the pilot gas pressure regulator cap.
2. Turn the pressure regulator adjustment screw clock-
wise to decrease the flame and counterclockwise to
increase it.
3. Replace the pressure regulator adjustment screw
cap.
Figure 11 - Pilot Flame Adjustment
Gas Pressure Adjustment
CAUTION: The maximum inlet gas pressure listed on
the rating plate must not be exceeded or damage
to the boiler/water heater may occur!
The minimum supply pressure listed on the rating plate
is for input adjustment.
NATURAL GAS: Optimum results are obtained when the
boiler/water heater is operated at its full input rating, with
3.8 in to 4.2 in
,
96.5 mm to 106.7 mm W.C. of manifold
pressure. The manifold pressure should not vary outside
this range. The gas valve pressure regulator has been
preset at the factory. If adjustment is necessary the
following steps must be followed:
1.
Attach a
20 in
,
508 mm W.C. manometer to the tap
on the manifold.
2.
Remove the regulator adjustment screw cap from
the gas regulator. On systems that do not use a
separate gas regulator, remove the adjustment screw
cap from the gas valve body on the valve closest to
the gas supply piping.
3.
Rotate the regulator adjustment screw clockwise to
increase the manifold pressure, counterclockwise to
decrease it.
4.
Replace the regulator adjustment screw cap and
manifold pressure tap plug.
CAUTION: Never force the regulator adjustment
screw beyond the stop limits or damage to the
regulator will occur!
PROPANE GAS: A manifold pressure of
11 in
,
279 mm
W.C. must be maintained for proper operation of the
boiler. If the manifold pressure is off by more than 5%
adjust it according to steps 1 through 4.
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 additional
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 to burn
10 ft
3
,
0.28m
3
of gas and divide
this time by 10.
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 adjust the manifold
pressure accordingly. DO NOT adjust the manifold
pressure by more than 5%. If a proper rate cannot
be maintained without adjusting the manifold
pressure beyond the 5% limit, the main burner
orifices must be replaced. If the input rate is too low,
go to the next larger size of main burner orifices. If
the input rate is too high, go to the next smaller size.
CAUTION: Never increase the input to the boiler/
water heater above that for which it is rated. Doing
so can cause premature failure of the unit!
CONTROL DESCRIPTION
Low Water Cutoff
If the boiler is to be installed above radiation or if
required by other codes or regulations, install a low
water cutoff in appropriate piping.
If installed, ensure that the low water cutoff device(s)
function properly. Test in accordance with the
manufacturer’s instructions included with the device(s).
Boiler Thermostat
If a thermostat is to be used to control the boiler always
follow the instructions included with the thermostat.
Proper location of the thermostat will ensure efficient
trouble-free operation of the boiler. Mount the thermostat
to an inside wall at a height approximately five feet
above the floor.
RIOM-48
