Weil-McLain GV90+ - Manual (Page 79)

Part number 550-142-054/0411
79
GV90+
gas
-
fired water boiler
— Boiler Manual
Troubleshooting
(continued)
Figure 94 Common causes and possible corrections, part 1
Symptom Common Causes Possible Corrections
Rapid cycling — boiler
turns on and off frequently
Thermostat installed where drafts
or heat affect reading
Locate thermostat on inner wall away from
heat sources or cool drafts.
Heat anticipator in thermostat
adjusted incorrectly
Adjust thermostat per manufacturer’s
instructions.
Incorrect limit setting Set limit according to system needs.
Maximum setting is 200°F. Increase limit
setting to decrease cycling.
Insufficient water flow through
boiler
Check all valves to and from boiler. Return
to proper setting.
Confirm circulator size.
Frequent release of water
through relief valve
Expansion tank sized too small Call qualified service technician to check
expansion tank operation and size.
Flooded expansion tank Call qualified service technician to check
expansion tank operation.
Inoperative limit control Call qualified service technician to replace
limit control.
Need to frequently add
makeup water
Leaks in boiler or piping Have qualified service technician repair
leaks at once to avoid constant use of
makeup water. Makeup water can cause
mineral deposits which, in turn, can cause
boiler section failure. Do not use petroleum-
base stop-leak compounds.
Black water condition Oxygen corrosion due to leaks in
boiler and piping
Have qualified service technician repair at
once. Keep pH of water between 7.0 to 8.5.