Control Descriptions; Check-Out Procedure - PEERLESS Stainless Steel Gas Boilers Installation, Operation & Maintenance Manual

START-UP PROCEDURES
C. CONTROL DESCRIPTIONS
See Figure 11.1 for location of these devices.
1. SUPPLY WATER TEMPERATURE THERMISTOR –
Senses supply water temperature from boiler. Shuts
down main burner gas upon reaching 10 degrees
over control board set point. As supply temperature
falls, boiler ignition will restart.
2. RETURN WATER TEMPERATURE THERMISTOR –
Senses return water temperature from system. As
thermistor senses a drop in return water temperature
below the control board set point minus the
differential set point, boiler ignition sequence begins.
3. WATER HIGH LIMIT SWITCH – Senses supply
water temperature and shuts down main burner gas
upon reaching limit set point. Boiler control will go
into lockout mode upon activation of high limit.
4. WATER PRESSURE SWITCH – Senses boiler water
system pressure and shuts down main burner gas
when pressure falls to 8 PSI. Boiler control will go
into lockout mode upon activation of water pressure
switch.
5. AIR PRESSURE SWITCH – Senses burner manifold
pressure and prevents ignition sequence activation if
blower is not operating.
6. THERMODISC TEMPERATURE SWITCH – Senses
combustion chamber outside surface temperature
and shuts down main burner gas upon reaching set
point of 210° F. Boiler control will go into lockout
mode upon reaching set point. This is a manually
resetable switch.
D. CHECK-OUT PROCEDURE
1. After starting the boiler, be certain all controls are
working properly. Check to be sure that boiler will
shut down on action of water temperature reaching
control board temperature set point.
2. To check operation of the ignition system safety
shut-off features:
a. Turn gas supply off.
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b. Set thermostat or controller above room
temperature to call for heat.
c. Ignition sequence should try 3 times before going
into lockout mode.
d. Turn gas supply on.
e. Reset by turning 120V power supply off then on.
f. Observe boiler operation through one complete
cycle.
3. Low Water Cut-Off (if used) – Consult the
manufacturer's instructions for the low water cut-off
operational check procedure.
4. Check the system to make sure there are no leaks or
overfilling problems which might cause excessive
make-up water to be added. Make-up water causes
liming in the boiler.
5. Check the expansion tank and automatic fill valve (if
used) to confirm that they are operating correctly. If
either of these components causes high pressure in
the system, the boiler relief valve will weep or open,
allowing fresh water to enter the system.
6. Check the general condition of the system including
piping support, joints, etc. Check cleanliness of the
radiators, baseboard units and/or convectors. Clean
them to the extent possible. If radiators do not heat
evenly, vent any remaining air from them.
7. Review operation with end-user.
8. Complete the Warranty Card and submit it to
Peerless Boilers.
9. Hang the Installation, Operation and Maintenance
Manual in an accessible position near the boiler.