Part number 550-143-010/1021
77
GV90+
series
2
gas-fired water boiler – boiler manual
Figure 85
Igniter
85060
Figure 86
Gas valve
Figure 87
Blower housing
85062
Figure 88
Thermal switch
Troubleshooting
(continued)
Igniter
Wait several minutes until igniter cools down before at-
tempting replacement. Failure to do so will cause severe
personal injury.
1. Disconnect igniter (Figure 85) from igniter wiring harness and
remove igniter before removing from blower assembly.
2. Replace igniter gasket if original gasket is frayed or damaged OR
if room-temperature resistance across igniter is not between 40
and 95 ohms.
3. Igniter is fragile — handle with care. Do not touch igniter surface
with bare hands. Body oils can cause failure of the carbide.
Gas Valve
The gas valve (Figure 86) operates with a negative
pressure at the outlet — approximately –0.2” w.c. —
DO NOT set gas pressure higher than this.
Follow instructions in this manual carefully if testing
gas valve outlet pressure. Failure to comply can result in
severe personal injury or death.
The gas valve outlet is bolted to the gas line adapter and
sealed with an o-ring. When replacing valve, replace only
with valve listed in this manual for use with the GV90+
boiler. Failure to comply could result in severe personal
injury, death or substantial property damage.
Blower Housing
Do not disassemble blower housing (Figure 87)
. A
fire or explosion causing severe personal injury, death or
substantial property damage can result. If you suspect a
problem, replace blower housing. Follow instructions on
for blower housing removal and replacement.
Thermal switch
1. The thermal switch (Figure 88) protects vent pipe from excess flue
temperatures.
2. If the thermal switch opens, the boiler will shut down, until the
vent system cools.
If the thermal switch opens, investigate the cause before
replacing switch and starting the boiler. DO NOT attempt
to jumper the switch. Failure to comply could result in
severe personal injury, death or substantial property
damage.
