Specifications

Part number 550-142-120/0113
– 89 –
WM97+ gas-fired water boiler — Boiler Manual
Startup — final checks
Check for gas leaks
Before starting the boiler, and during initial operation,
use a leak detector or smell near the floor and around
the boiler for gas odorant or any unusual odor. Remove
boiler front door and smell the interior of the boiler
jacket.
Do not proceed with startup if there is any
indication of a gas leak. Repair any leak at once
.
DO NOT adjust or attempt to measure gas valve out-
let pressure.
The gas valve is factory-set for the correct
outlet pressure. This setting is suitable for natural gas
and propane, requiring no field adjustment. Attempting
to alter or measure the gas valve outlet pressure could
result in damage to the valve, causing potential severe
personal injury, death or substantial property damage.
Propane boilers only — Your propane supplier mixes
an odorant with the propane to make its presence de-
tectable. In some instances, the odorant can fade, and
the gas may no longer have an odor. Before startup
(and periodically thereafter), have the propane supplier
verify the correct odorant level in the gas.
Check thermostat circuits
1. Disconnect wires connected to the Zone 1, Zone 2 and
Zone 3 thermostat terminals (see Field wiring, beginning
on page 66 for low voltage terminal locations and appli-
cation information). Mark the wires before removing to
avoid wiring errors when re-connecting them.
2. Connect a voltmeter across each pair of incoming wires.
Close each thermostat, zone valve and relay in the external
circuits one at a time and check the voltmeter reading
across the incoming wires.
3.
There should NEVER be a voltage reading.
4. If a voltage does occur under any condition, check and
correct the external wiring.
DO NOT connect the WM97+ thermostat ter-
minals to 3-wire zone valves
. This could cause
WM97+ control damage.
5. Once the external thermostat circuit wiring is checked and
corrected if necessary, reconnect the external thermostat
circuit wires.
Inspect/fill condensate system
Inspect/check condensate lines and fittings
1. Inspect the condensate drain line, condensate PVC fittings and
condensate trap. (See page 62 for component locations.)
Fill condensate trap with water
1. Loosen the top nut that secures the condensate trap body to
the boiler condensate connection (see Figure 98). Pull the trap
down to disengage from heat exchanger.
Figure 98
Disconnect condensate trap assembly to fill trap
body with water
70 or 110
Nut
Nut
155
2. Pull the trap body forward enough to allow pouring water into
the top of the trap.
3. Fill the trap with fresh water until water begins to run into the
condensate drain tube.
4. Reattach the trap body by sliding onto the boiler condensate
outlet, then retightening the trap body nut.
The condensate trap must be filled with water during
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.