47
3) Twobasictypesoferrorscodesareshownonthedisplay:
• SoftLockoutCodes–Whenasoftlockoutoccurs,theboilerwillshutdownandthedisplaywillalternate
betweenthenumber“9”andtheletter“b”followedbyatwodigitservicecode.Alistofthese 
codes,andtheirmeanings,isshowninTable13.3.Theboilerwillautomaticallyrestartoncetheconditionthat
causedthelockoutiscorrected.
• HardLockoutCodes–Whenahardlockoutoccurs,theboilerwillshutdownandthedisplaywill 
ashthe letter“E”followedbyatwodigitservicecode.Alistofthesecodes,andtheirmeanings,is
showninTable13.4.Oncetheconditionthatcausedthelockoutiscorrected,theboilerwillneedtobe 
manuallyresetusingtheRESETbuttononthedisplay.
4) Ifanoutdoorsensorisinstalled,theboilerwillautomaticallyadjusttheheatingzonesetpointtemperature
basedontheoutdoorresetcurveinFigure11.4.Themaximumsetpointisdenedbyparameter4(factoryset
to180°F)whentheoutdoortemperatureis0°Forbelow.Theminimumsetpointtemperatureshownis100°F
whentheoutdoortemperatureis60°Forabove.Astheoutdoortemperaturefallsthesupplywatertarget
temperatureincreases.Forexample,iftheoutdoorairtemperatureis30°F,thesetpointtemperatureforthe
supplywateris140°F.
5) Anindirectwaterheaterthermostatcanbeconnectedbetweenterminals7and8ontheterminalstrip.When
thisthermostatcloses,thecentralheatingcirculatorwillbeturnedoffandtheDHWcirculatorwillbeturned
on.
6) Anexternallimitcontrolcanbeinstalledbetweenterminals3and4ontheterminalstrip.Besuretoremove
thejumperbetweenterminals3and4whenaddinganexternallimitcontroltothesystem.Iftheexternallimit
opens,theboilerwillshutdownanderrorcode“b26”willbedisplayed.Ifthelimitinstalledisamanual
resettype,itwillneedtoberesetbeforetheboilerwilloperate.
Table 11.3: Boiler Status Codes
First Digit Boiler Status
0Burner off - No call for heat or DHW
1 Pre-purge or post-purge
2 Ignition
3Burner responding to call for heat
4Burner responding to call for DHW
5Checking air pressure switch
6Burner off - Set point temperature has been reached
7Call for heat ended. 10s heating post pump period
8Call for DHW ended. 10s DHW post pump period
9 and b
Flashing
Burner off - on soft lockout. See Troubleshooting
Section to determine meaning of error code.
ABoiler responding to call from heating zone
H Burner on - Held in high re
LBurner on - Held in low re