Weil-McLain GV90+ - Inspect temperature mixing system

Part number 550-142-903/1016
71
Inspect temperature mixing system
1. Carefully check the TEMPERATUREof the SYSTEMRETURNPIP
ING
as it passes through the boiler jacket and on the RETURN
PIPEINSIDETHEBOILERJACKET
just before it enters the boiler
sections. You may do this with a surface pyrometer or by
lightly touching the piping with your fingers.
To avoid potential of severe burn — $ONOTREST
HANDSONORGRASPPIPES
. Use a light touch only.
Return piping may heat up quickly.
2. The temperature of the water entering the system should
quickly heat up to about
&, being considerably hotter
than the return water from the system.
3. This is accomplished with the
TWOINTERNALBOILERCIRCULA
TORS
. The Bypass circulator (page 2, item 7) takes hot water
from the boiler supply outlet and blends it with return water.
The System circulator (page 2, item
6) slows down to aid in
raising the return temperature entering the sections.
4. If the
TEMPERATUREMIXINGSYSTEM does not work correctly,
check the two circulators to be sure they are flowing water. If
the circulators are operating normally but the temperature
mixing system does not maintain water at the entrance to the
boiler sections at 140°F, you may need to replace the boiler
IBC or water temperature sensor (page 2, items
1 and 8).
Inspect additional controls and cutoffs
1. Inspect and test the boiler additional controls. Verify opera-
tion by turning control set point below boiler temperature.
Boiler should cycle off. Return dial to original setting.
2. Inspect and test additional limit controls or low water cut-
offs installed on system. Follow the device manufacturer's
instructions.
Inspect gauges
1. Boiler pressure/temperature gauge — Inspect gauge and check
whether readings are reasonable. Replace if any signs of leakage
from case or improper readings.
2. System gauges (if installed) — Inspect and check readings of
other gauges in system.
&IGURE Blower motor
Inspect blower motor
1. Oil blower motor only if required, some GV90+
boilers may have an alternate sealed bearing blower
motor, (No oiling required).
2. See Figure 79. For blower motors that do require oiling,
with boiler power OFF, place a few drops of Anderol 465
in each of the two oil cups.
Use only !NDEROL  to lubricate the
blower motor. Do not use universal house-
hold oils. Motor could be damaged, result-
ing in possible severe property damage.
Not required on
Inspect oiled-bearing circulators
1. Both of the circulators installed in the boiler are water-
lubricated. No oiling is required.
2. Check other circulators in the system. Oil any circulators
requiring oil, following circulator manufacturer’s instruc-
tions. Over-oiling will damage the circulator.
Inspect Temperature sensor
1. The temperature sensor may accumulate deposits on the
probe surface. Annual inspection and cleaning of the
probe will improve boiler performance.
Disconnect power, unplug harness from sensor.
a. Drain boiler water to a level below the sensor.
b. Remove sensor from boiler using a deep well socket.
c. Wipe any built up contaminates from probe and
insulator surfaces.
d. Reinstall using a deep well socket sensor into the
boiler. Do not overtighten.
GV90+ Series 2 GAS-FIRED WATER BOILER — Boiler Manual
Annual start-up (continued)