Harman HydroFlex 60 Pellet Boiler - Setting The Boiler Temperature; Control Board Operation

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3-90-233R24_11/13
Setting The Boiler Temperature
Without the Outdoor Air Temp - Sensor Installed
Tosetthemaximumboilerwatertemperature,simplyturn
theMax.Temp.watertemperaturedialtothedesiredsetting.
Thecontrolandtheboilerwillthenperformtoachieveand
maintainthesettemperature.
The Min. Temp. Knobis the boiler water temperature
minimum,orthelowesttemperaturethewaterwillgobefore
theunitre-starts.Turningtheknobfullycounterclockwiseis
the“OFF”position,whileturningtheknobclockwise,past
the140degreemarking,isthe“ON”position.
With The Outdoor Air Temp - Sensor Installed
Maximumboilertempsettingisasdescribedabove,withthe
addedfeatureofautomaticmaximumwatertempcontrolled
bytheOATsensor.
TheMIN.TEMP.knob,inadditiontobeingthemodesetting
(onoroff),alsohasthefunctionofsettingtheminimumboiler
watertemperature.Thiswould bethelowest boilerwater
temperaturethatyouwanttohavebasedonthefollowing
factors;
1. OutdoorAirTemperature(OAT)
2. DomesticHotWaterUse
  a.HotWaterCoilOption
  b.IndirectHotWaterStorage
3. OverallVolumeoftheHeatingSystem
The boiler is designed to withstand lower return water
temperatures. However, extended return temperatures below
140 degrees F can cause condensation.
NOTE: If the system is run at the lower temperature settings,
conditions of the rebox, boiler tubes, secondary ash chamber
and venting should be monitored closely. If any indications
show excess condensation, the boiler water temperature
will need to be increased until condensation does not occur.
Operation
Control Board Operation
Aquastat Sensor-Thissensorislocatedbehindthecontrol
panel.This sensor,along with the outdoor airsensor, is
whatthecontrolboardusestoregulatetheburnratebased
on the observed conditions. (BoilerTemp.& OutdoorAir
Temperature)
Outdoor Air Temp - Sensor (OAT): This sensor is located
outsidethebuilding(onthenorthsideofthehouseandout
ofdirectsunlight).TheOutdoorAirSensorisusedtoperform
hotwaterresetbasedonoutdoorairtemperatures.
WhentheOATsensorisinstalled,at20°F.orbelow(outside
temperature),theboilerwilloperateatthetemperatureset
ontheMAX.TEMP.knob.Theboilerwatertemperaturewill
decreaseby1degreeF.forevery1degreeF.intemperature
rise(above20°)oftheoutdoorair.
NOTE: Pellet Boiler Outdoor Air Reset Operation Graph
located on page 28.
WATER TEMPERATURE
MAX. TEMP.
MIN. TEMP.