Part number 550-143-010/1021
71
GV90+
series
2
gas-fired water boiler – boiler manual
Inspect temperature mixing system
1. Carefully check the
temperature
of the
system return
piping
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 pyrom-
eter or by lightly touching the piping with your fingers.
To avoid potential of severe burn —
Do 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
140°F
, 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 (
, item
6
) slows down to
aid in raising the return temperature entering the sections.
4. If the
temperature mixing system
does not work cor-
rectly, 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/LWCO sensor
(
, 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 g
auges
1. Boiler pressure/temperature gauge — Inspect gauge and check
whether readings are reasonable. Replace if any signs of leak-
age from case or improper readings.
2. System gauges (if installed) — Inspect and check readings
of other gauges in system.
Figure 79
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
Anderol 465
to lubricate the blower motor.
Do not use universal household oils. Motor could be
damaged, resulting in possible severe property damage.
Not required on
Inspect oiled-bearing circulators
1. Both of the circulators installed in the boiler are water-lubri-
cated. No oiling is required.
2. Check other circulators in the system. Oil any circulators re-
quiring oil, following circulator manufacturer’s instructions.
Over-oiling will damage the circulator.
Inspect Temperature/LWCO sensor
The temperature/LWCO 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 sensor into the boiler using a deep well
socket. Do not overtighten.
e. Refill boiler.
Annual start-up
(continued)
