Daikin DR80TN Service Instructions Manual

Two Stage Furnace with Nine Speed ECM Motor
Pride and workmanship go into every product to provide
our customers with quality products. It is possible, however,
that during its lifetime a product may require service.
Products should be serviced only by a qualified service
technician who is familiar with the safety procedures
required in the repair and who is equipped with the proper
tools, parts, testing instruments and the appropriate service
manual. REVIEW ALL SERVICE INFORMATION IN THE
APPROPRIATE SERVICE MANUAL BEFORE
BEGINNING REPAIRS.
Only personnel that have been trained to install, adjust,
service, maintenance or repair (hereinafter, "service")
the equipment specified in this manual should service the
equipment.
This equipment is not intended for use by persons
(including children) with reduced physical, sensory or
mental capacities, or lack of experience and knowledge,
unless they have been given supervision or instruction
concerning use of the appliance by a person responsible
for their safety.
Children should be supervised to ensure that they do not
play with the equipment.
The manufacturer will not be responsible for any injury
or property damage arising from improper supervision,
service or service procedures. If you service this unit, you
assume responsibility for any injury or property damage
which may result. In addition, in jurisdictions that require
one or more licenses to service the equipment specified in
this manual, only licensed personnel should service the
equipment. Improper supervision, installation, adjustment,
servicing, maintenance or repair of the equipment specified
in this manual, or attempting to install, adjust, service
or repair the equipment specified in this manual without
proper supervision or training may result in product
damage, property damage, personal injury or death.
This furnace may be paired with a cooling unit that uses
R-32 refrigerant. If the refrigeration unit paired with this
furnace does not use R-32, the R-32 function in the furnace
control board to be turned off. Please see the electrical
and the R-32 sections for more details.
Refrigerant systems other than 410A or R32 may require
an additional mitigation control board. Refer to the
installation manual of the indoor evaporator coil to
determine installation requirements for that supplier's
refrigerant detection system.
Copyright © 2021-2023
Service Instructions
Daikin DR80TN/DD80TN
WARNING
WARNING

TABLE OF CONTENTS

IMPORTANT INFORMATION ..........................................2
PRODUCT IDENTIFICATION ..........................................4
SYSTEM OPERATION .....................................................5
SCHEDULED MAINTENANCE ......................................15
SERVICING .....................................................................19
Checking Voltage ....................................................20
Checking Wiring ......................................................20
Checking Thermostat And Wiring .........................20
Checking Transformer And Control Circuit .....20
Checking Air Circulator Blower
Motor (Multi-Speed ECM Motor) .........................21
Checking Air Circulator Blower
Motor (9-Speed ECM Motor) .................................21
Checking Duct Static .............................................21
Checking Temperature Rise ..................................22
Checking Primary Limit Control ..........................22
Checking Auxiliary Limit Control .........................23
Checking Flame Rollout Control ........................24
Induced Draft Blower Motor ...............................25
Checking Gas Valve (Redundant) .........................25
Checking Main Burners .........................................25
Checking Orifices ...................................................25
Checking Gas Pressure .........................................26
Checking Hot Surface Ignitor ..............................28
Checking For Flashback ........................................28
Checking Pressure Switch ..................................28
Checking For Delayed Ignition .............................29
Checking Integrated Ignition Control Boards .29
Checking Flame Sensor .......................................29
AIRFLOW TABLES .........................................................30
TROUBLESHOOTING CHART ......................................35
WIRING DIAGRAMS ......................................................42
Do not bypass safety devices.
WARNING
RSD6621304
December 2023