EngA DJM3 - Page 16

A DJM3
IOM-17 16 of 27 Mar 99 R3
BurnerSelection
TheDJM3isdesignedtooperatewithboththestandard(roundburnerplate)andhighturndown
(rectangular)burners.TheselectionismadebycuttingajumperwireR100whichislocatedonthe
smallboard.(TheDJM3mustbeturnedovertoaccessthejumperwire.)

NOTE: JumperwireR100iscutonlyforthehighturndownburneroperation.Caution–donotcut
resistorR100onthelargeboard.

NOTE: Donotadjustanyotherpotslocatedonthesmallboard,whicharenotaccessiblefromthe
frontoftheDJM3

CombustionSetUp
Whenmeasuringcombustiongases,ensureprobeofanalyserinsertsfullyintotheflueconnectionto
theheatexchanger.Measuringattheflueoutletmaybeadilutedreadingduetoairmixingintothe
flue.

NOTE: Ifcombustionisnotsetcorrectlyitcanresultimproperburningwhichmayproduce
productsofcombustionthatsmell,carbonandoranexcessiveamountofwaterintheflue.
Careshouldbetakentosetburnersupproperly.Notethattemperatureoftheairandfuel
mayhaveagreataffectonthesetupselected.Ifboththecombustionairandthefuelare
ataconstanttemperaturethroughouttheheatingseason,oncecombustionissetitshould
remainsimilarthroughtheseason.

HighTurndown(Rectangular)Burner
MosthighturndownDJunitswillemployonofthefollowingMaxitrolmodulatingDCvoltgasvalves.

Series20 420,M520,M620.Thesevalvesdonothavehighfireregulators.Highfirepressureis
setupattheapplianceregulator.
Series50 550,M650,ES350.Thesevalvesdonothavehighfireregulators.Highfirepressureis
setupattheapplianceregulator
ES345D‐L Thisvalvehasabuiltinhighfireregulator.TypicallyusedonDJ140models.

Theabovevalvesdifferfromeachotherinsize,configuration,BTUcapacity,physicallayout,andlow
firesetup.
Check the equipment to verify what type of modulating gas valve you have to ensure the correct
combustionsetupmethodisused.
 