Startup - Final Checks - Weil-McLain SlimFit 2 Series Manual

SlimFit ® Series 2
Startup — final checks
Check thermostat circuit(s)
1. Disconnect the two external wires connected to the boiler
thermostat terminals (see instructions beginning on page 47
for terminal locations).
2. Connect a voltmeter across these two incoming wires. Close
each thermostat, zone valve and relay in the external circuit
one at a time and check the voltmeter reading across the
incoming wires.
There should NEVER be a voltage reading. Ap-
plying voltage across the thermostat terminals will
damage the control. If a voltage does occur under
any condition, check and correct the external wir-
ing. (This is a common problem when using 3-wire
zone valves.)
3. Once the external thermostat circuit wiring is checked and
corrected if necessary, reconnect the external thermostat
circuit wires. Allow the boiler to cycle.
Inspect/fill condensate system
Inspect/check condensate lines and fittings
1. Inspect the condensate drain line and condensate trap. (See
page 44 for component locations.)
Fill condensate trap with water
1. Fill the condensate trap with fresh water, either by removing,
filling and re-installing or by pouring water into the inspection
caps near the flue connection (piping end of boiler).
2. To remove the trap, see page 44 for information.
a. Loosen the two stainless steel hose clamps on the
flexible coupling
b. Slide the flexible coupling over the 1" PVC pipe
connected to the trap.
c. Loosen the condensate trap inlet connection.
d. Remove condensate trap and flush as needed.
The condensate trap must be filled with water dur-
ing all times of boiler operation to avoid flue gas
emission from the condensate drain line. Failure
to fill the trap could result in severe personal injury
or death.
Inspect pressure switch hoses
The pressure switch sense lines must be in good
condition and firmly attached to the correct loca-
tions. Incorrect placement or disconnected sense
lines can result in unreliable boiler operation.
1. Inspect all pressure switch sense hoses and verify that they
are correctly installed (Figure 73). Replace if necessary.
2. Inspect and verify attachment of the plastic gas valve/venturi
reference line (Figure 81, page 90). Replace if necessary.
Final checks before starting boiler
Read the instructions to adjust and set up the control
module. Verify that all settings have been made cor-
rectly.
Verify that the boiler and system are full of water and
all system components are correctly set for operation.
Part number 550-100-561/0224
commercial condensing gas
- — Boiler Manual
fired water boiler
Figure 73
Pressure switches
WHITE hose
to blower housing
BLACK hose to burner end sec-
tion lower center hose barb
WHITE hose to hose barb on
the side of the venturi
Vent any remaining air from system using manual vents.
Air in the system will interfere with circulation and cause
heat distribution problems and noise.
Check system piping for leaks. If found, shut down boiler
and repair immediately.
Eliminate all system leaks. Continual fresh make-
up water will reduce boiler life. Minerals can build up
in sections, reducing heat transfer, overheating heat
exchanger, and causing heat exchanger failure.
Fill condensate trap with water (see above for proce-
dure).
Verify electrical connections are correct and securely
attached.
Inspect vent piping and air piping (direct vent systems)
for signs of deterioration from corrosion, physical dam-
age or sagging. Verify vent piping and air piping are
intact and correctly installed per this manual.
Venting system must be sealed gas-tight to prevent
flue gas spillage and carbon monoxide emissions
which will result in severe personal injury or death.
Before starting the boiler, and during initial opera-
tion, use a leak detector or smell near the floor and
around the boiler for gas odorant or any unusual
odor. Remove boiler access door and smell interior
of boiler enclosure. Do not proceed with startup if
there is any indication of a gas leak. Repair any
leak at once.
If you discover evidence of any gas leak during
operation, shut down the boiler at once. Find the
leak source with bubble test and repair immediately.
Do not start boiler again until corrected. Failure to
comply could result in severe personal injury, death
or substantial property damage.
Y-fitting with WHITE
hoses to top of switches
Min air
flow switch
Flue pressure
switch
81