Weil-McLain WM97+70 Manual page 96

WM97+ -
gas fired water boiler
Annual startup
Check air openings
1. Verify that combustion and ventilation air openings to the
boiler room and/or building are open and unobstructed.
2. Check operation and wiring of automatic combustion air
dampers, if used.
3. Verify that boiler vent discharge and air intake are clean and
free of obstructions.
Flue vent system and air piping
1. Visually inspect entire flue gas venting system and combus-
tion air piping for blockage, deterioration or leakage. Repair
any joints that show signs of leakage in accordance with vent
manufacturer's instructions. Verify that air inlet piping is
connected and properly sealed.
Failure to inspect for the above conditions and have
them repaired can result in severe personal injury
or death.
Check water system
1. Verify all system components are correctly installed and
operational.
2. Check the cold fill pressure for the system. Verify it is correct
(usually around 12 PSIG).
3. Watch the system pressure as the boiler heats up (during
testing) to ensure pressure doesn't rise too high. Excessive
pressure rise indicates expansion tank sizing or performance
problem.
4. Inspect automatic air vents and air separators. Remove air
vent caps and briefly press push valve to flush vent. Reinstall
caps. Make sure vents do not leak. Replace any leaking vents.
5. Check system water chemistry (pH, hardness and inhibitor
level). See page 85.
Check expansion tank(s)
1. Expansion tanks provide space for water to move in and
out as the heating system water expands due to temperature
increase or contracts as the water cools.
2. WM97+155 only — See page 41 for information.
3. WM97+70 and 110 only — The boiler is fitted with an inte-
gral diaphragm-type tank (12 liters, 3.2 gallons). The tank is
factory charged to 12 PSIG.
a. Supplementary expansion tanks, if used, may be closed
or diaphragm or bladder type. See page 40 of this manual
for suggested location of supplementary expansion tanks
and air eliminators.
4. Tank types
• Closed-type — welded gas tight and located above boiler.
Tank is partially filled with water, leaving an air cushion
for expansion.
• Make sure a closed-type tank is fitted with a tank fit-
ting, such as the B & G Tank-Trol or Taco Taco-Trol.
This fitting reduces gravity circulation of air-saturated
tank water back to the system and prevents the air
from bubbling up through the water as it returns
from the system.
– 96 –
— Boiler Manual
(continued)
5. If relief valve has tended to weep frequently, the expansion
Inspect ignition electrode
1. Remove the ignition electrode from the boiler heat exchanger
2. Remove any white oxides accumulated on the ignition elec-
3. Reinstall ignition electrode, making sure gasket is in good
4. Re-attach the ground wire to the electrode assembly.
• Do not use automatic air vents in systems with closed-
type tanks. The air will escape from the system instead
of returning to the tank.
• Eventually, the tank will waterlog and no longer
control pressurization. The boiler relief valve will
weep frequently.
Diaphragm- or bladder-type
•
a rubber membrane to separate the tank pressurizing air
and the water. May be located at any point in the system,
but preferably located on the suction side of the system
circulator.
• Systems with this type of expansion tank require at
least one automatic air vent, preferably located on
top of an air eliminator, as shown in examples in
this manual.
tank may be waterlogged or undersized.
a. WM97+70 or 110 only — If system volume is greater
than 15 gallons, a supplementary expansion tank may be
needed (see page 40). Check the following.
•
Integral expansion tank in boiler
tank charge pressure by closing the expansion tank
isolation valve. Allow the tank to cool off. Isolate the
tank by disconnecting from the boiler internal piping.
Then check the charge pressure in the tank. It should
be 12 PSIG. If necessary, adjust tank pressure.
Relieve pressure from the system before isolat-
ing the 70/100 internal expansion tank. If remov-
ing the tank for service or replacement, the tank
may contain some water, which could be hot.
b.
Diaphragm- or bladder-type expansion tank
check tank size to be sure it is large enough for the sys-
tem. If size is too small, add additional tank (or tanks) as
necessary to provide sufficient expansion. If tank size is
large enough, remove tank from system and check charge
pressure (usually 12 PSIG for residential applications). If
tank won't hold pressure, membrane has been damaged.
Replace tank.
c.
Closed-type expansion tank
waterlogged. Install a tank fitting if not already installed.
Then check fill level per fitting manufacturer's instruc-
tions. If fill level is correct, check tank size against
manufacturer's instructions. Replace with a larger tank
if necessary.
access cover (see item 26, page 3 or page 5). (Disconnect the
ground wire and ignition cable connected to the electrode.)
trode using steel wool. If the ignition electrode cannot be
cleaned satisfactorily, replace ignitor with a new one.
condition and correctly positioned.
— Use a torque wrench when tight-
TORQUE LIMIT
ening the two ignition electrode retainer screws.
DO NOT exceed 20 inch-pounds.
— welded gas tight with
— Check the
— first,
— tank is most likely
Part number 550-142-085/0712