Burnham K2WTC - Troubleshooting

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107774-01- 9/17
XV. Troubleshooting
A. Troubleshooting problems where no error code is displayed.
WARNING
Electrical Shock Hazard. Turn off power to boiler before working on wiring.
Problem Condition Possible Causes
Inadequate
Space Heat
Boiler not responding
to call for heat,
“Status” and “Priority”
show “Standby”.
Boiler is not seeing call for heat. Check thermostat or zone wiring for loose
connection, mis-wiring, or defective thermostat/zone control.
Boiler not responding
to a call for heat,
“Status” shows
“Standby” and
“Priority” shows
“Central Heat”.
Supply temperature is greater than set point:
• Water ow through system loop non-existent or too low, due to inoperable
system circulator, air, or failure of zone valve(s) to open.
• May be normal if heating load is below the boiler’s minimum ring rate (e.g. if one
“microzone” is calling for heat).
• Defective diverting valve or loose electrical connection to valve.
Home is cold during
mild weather days
Increase Low Boiler Water Temperature parameter 5°F (2.8°C) per day.
Home is cold during
cold weather days
Increase High Boiler Water Temperature parameter 5°F (2.8°C) per day
Priority shows
Domestic Hot Water
Normal operation: Boiler does not provide space heat when it is responding to a DHW
demand. Priority time can be shortened, but this may cause a lack of hot water at
xtures during long DHW draws.
No hot water
at xtures
Boiler not responding
to call for DHW,
“Status” and
“Priority” show
“Standby”.
Boiler is not seeing DHW demand:
• Verify that draw rate though boiler itself is at least 0.5GPM (a higher draw may be
needed at the xture due to mixing at the xture and/or the tempering valve.
• Defective DHW ow switch or loose connection at switch
Boiler was
responding to call
for DHW, but priority
is now shown as
Central Heat
Simultaneous calls for DHW and space heat were present for the priority time (default
is one hour). Increase priority time.
Inadequate
hot water at
xtures
Boiler not ring
during a call a call
for DHW, “Status”
shows “Standby”
and “Priority” shows
“Domestic Hot
Water”.
DHW temperature is greater than set point.
• Normal at very low draw rates (boiler will cycle on and off).
• Misadjusted or defective tempering valve
Boiler ring
continuously at
100%
DHW draw and/or temperature rise is in excess of capacity shown in Table 2.2.
Boiler not ring
continuously
at 100%, but
temperature is too
low.
• Mixing valve set too low.
• DHW setting on boiler lower than, or too close to, tempering valve setting.
• Fouled plate heat exchanger
SEE WARNINGS ON PAGE 119 BEFORE MAKING ADJUSTMENTS TO BOILER OR
VALVE