York Sun Select YV28, Manual

Page: 88 / 110

Gas heat start-up
The following sections describe the gas heat start-
up procedures.
Gas heat pre-start checklist
About this task:
When the installation is complete, perform the
following checks:
1. Check the type of gas supply. Verify that it is
the same as the gas supply listed on the unit
nameplate.
2. Verify that the combustion air intake and flue
exhaust are free of any debris or obstruction.
3. Verify that the hood is installed over the flue
exhaust discharge opening.
4. For modulating furnaces, set the System
Selection bottom pin jumper to COMMISSION
on the Modulating Furnace Control to
properly check the input rate and manifold
pressure.
Operating instructions
CAUTION
This furnace is equipped with an automatic re-
ignition system. DO NOT attempt to manually light the
burners.
Gas heat post-start checklist
About this task:
After the entire control circuit has been energized
and the heating section is operating, perform the
following checks:
1. Check for gas leaks in the unit piping and the
supply piping.
WARNING
FIRE OR EXPLOSION HAZARD
Failure to follow the safety warning exactly could
result in serious injury, death, or property damage.
Never test for gas leaks with an open flame. Use
a commercially available soap solution made
specifically for the detection of leaks to check all
connections. This may result in a fire or explosion,
causing property damage, personal injury, or loss of
life.
2. Check for the correct manifold gas pressures,
input rates, and air temperature rise. See
Checking Gas Heat Input section.
3. Check the supply gas pressure. It must
be within the limits shown on the rating
nameplate.
Note: You must check the supply pressure
with all gas appliances in the building
at full fire. The standby gas pressure
must never exceed 13 in. or the operating
pressure drop below the minimum as
specified on the unit rating plate. If the gas
pressure is outside these limits, contact
the local gas utility or propane supplier for
corrective action.
Table 68: Natural gas inputs and pressures
Gas input
(MBtu/h)
Manifold pressure
(in. W.C.)
Supply pressure
(in. W.C.)
Fuel
Gas
model
Normal Reduced Normal Reduced Min Max
(N,S)1 400 320 3.5 2.5 5.8 10.5
Natural
Gas
(N,S)3 620 400 3.5 2.5 6.0 10.5
Note: Propane inputs and pressures
are provided in the listed conversion kit
instructions. Modulating furnaces are NOT
certified for use with propane and cannot
be converted.
Shutting down the unit
1. Set the thermostat to the lowest temperature
setting.
2. Turn off all electrical power to unit.
3. Open the gas heat access panel.
4. Turn the gas valve switch to the OFF position.
Installation Manual: YORK
®
Sun™ Select YV28 to YV50
88
Johnson Controls Ducted Systems