FieldBench

Daikin

DM96VC

Furnace · Daikin ComfortNet / Daikin One · two-stage · communicating VS · 96%

Daikin-badge ComfortNet / Daikin One 96% two-stage with a communicating variable-speed blower and a triple 7-segment IFC. Same factory family as Amana AMVC96 / Goodman GMVC96. Use the ComfortBridge E / b / d set (E0–EA, b0/b1/b2, d0) — not the AR9T96 E-only 24V card.

Not Amana AR9T96 / Goodman GR9T96 (single 7-seg E0–E9, 9-speed taps, no b/d codes). Not DM97MC (modulating percent capacity, not two-stage). Not a VRV indoor. A Daikin One on a 24V GR9T96 is a mis-pair.

Walk this in Diagnose

This plate

AFUE
Two-stage 96% condensing
Blower
Communicating VS ECM · CFM requested on the serial harness, not taps
Control
ComfortNet / ComfortBridge IFC · triple 7-segment + menu buttons
Bus
ComfortNet / Daikin One data pair. 24V fallback exists on some IFCs
Staging
Two-stage valve · two-speed inducer · dual pressure switches (E1/E2 vs E8/E9)
Sister SKU
Amana AMVC96 / Goodman GMVC96 — same IFC family, Daikin badge

This board

ComfortNet / Daikin One IFC · triple 7-segment

  • Three digits. Status words (idle, Ht1, Ht2, CF, dF) are not faults. Do not replace a board because it says Ht1.
  • Faults are the ComfortBridge set: E0–EA for gas/safety, b0/b1/b2 for the serial blower, d0 for network/shared data. EE is bus or internal depending on board date — believe the Daikin One English plus this door card.
  • This is not AR9T96 E-only. AR9T96 has no b0/b1/b2/d0 and will not talk Daikin One.
  • Learn / menu buttons step CFM, staging, and last faults. A setup screen is not a lockout.

Sequence

  1. Call. Daikin One / ComfortNet requests heat capacity. On 24V fallback, W1/W2 behave like a two-stage furnace but CFM still comes from the IFC tables — no taps.
  2. Inducer / PS. Low inducer → low PS (E1 stuck closed, E2 open). High inducer → high PS (E8 stuck closed, E9 open). Same physics as AR9T96, ComfortBridge presentation.
  3. HSI / valve. Nitride igniter, two-stage valve, flame rod µA. Failures stack to E0. Open igniter / no-ground is E7. Weak flame is E6.
  4. Blower. Serial ECM. b0 = not running, b1 = lost comms, b2 = HP / shared-data mismatch. A tap jumper from a GR9T96 motor will not run this blower.
  5. Network. d0 = shared data not on the network (memory card / learn). Outdoor or stat dropping the bus is EE / d-code territory, not a furnace E2.

Faults on this IFC

  • idle / Ht1 / Ht2 / CF

    Status, not a fault

    info

    Ready, low heat, high heat, or continuous-fan CFM on the triple display.

    • Do not change the board because it says Ht1 or CF.
    • CF is continuous fan, not a capacitor.
    • Ht1 forever with a high-stage request → E9 / staging, not a bad status word.
  • E0

    Retry / recycle lockout

    lockout

    Failed to sense flame after the retry limit (typically three trials). One-hour-class auto retry.

    • Watch one full try: inducer, HSI, valve, flame, µA.
    • Gas supply and manifold low then high.
    • Do not keep resetting — find which step dies.
  • E1

    Low-stage PS stuck closed

    lockout

    Low-fire pressure switch is made with the inducer off.

    • Unplug the LPS. Code change = switch or water-filled hose.
    • Do not confuse with AR9T96-only extras (Ed / En / EEJ) — those are the 24V 9-speed card.
  • E2

    Low-stage PS open

    lockout

    Inducer on low, low-fire switch never closes. Classic 96% trap / PVC.

    • Inducer 120 VAC and spinning.
    • Collector, trap, PVC intake/exhaust, wind.
    • LPS hose on the low tap, not teed to high.
    • Open > ~5 min can 1-hour lockout then retry.
  • E3

    Open limit / rollout circuit

    warn

    Primary, auxiliary, or rollout opened. ComfortNet bundles these on E3 — inspect rollout before you treat it as a dirty filter.

    • Heat CFM in the IFC menu, not a tap.
    • Filter, coil, return, static.
    • Rollout portion: exchanger / burners / flue. Manual reset. Recurring rollout is hazard.
  • E4

    Flame when no flame should be present

    hazard

    Rod sees flame with the valve de-energized.

    • Shut the gas cock. Leaking valve — replace, do not jump.
    • Flame-sense short or IFC input.
  • E5

    Open fuse

    warn

    24 V automotive fuse on the IFC is open.

    • Short on W/Y/G, humidifier, EAC, or the valve harness.
    • Unplug the tstat/data harness and replace the fuse. If it blows again the short is on-board or in the cabinet.
  • E6

    Low flame signal

    warn

    Flame present, µA below the IFC threshold.

    • Clean rod, chassis ground, manifold / LP conversion.
    • µA per this door card, not the AR9T96 sticker.
  • E7

    Igniter / no-ground

    lockout

    Open or cracked HSI, bad igniter connection, or missing equipment ground.

    • Igniter ohms and 120 VAC during warm-up.
    • IFC and burner-box ground.
  • E8

    High-stage PS stuck closed

    lockout

    High-fire switch is made with the inducer not on high. Furnace may stay on low.

    • This is the second switch — not E1.
    • Welded HPS or water in the high hose.
    • W2 shorted so the IFC thinks it is already on high.
  • E9

    High-stage PS open

    lockout

    Inducer on high, high-fire switch never closes. Runs on low, will not go high.

    • Inducer actually changes speed?
    • HPS hose on the high tap only.
    • Vent capacity / condensate only under high fire.
  • EA

    Reversed polarity / ground

    lockout

    115 V L1/N reversed, 24 V transformer reversed, or poor chassis ground.

    • Hot/neutral at the IFC, not just the disconnect.
    • Burner box ground screw.
  • EE

    Bus / internal

    lockout

    ComfortNet / Daikin One data dropped, or (on some dates) no 115 V / internal IFC fault. Stat English tells you which.

    • Data pair polarity and splices. This is not 24 V Y.
    • Only one communicating master. Leftover data wires landed on R/C after a 24V conversion.
    • Door switch, disconnect, and 115 V at the IFC if the display is dark / EE on power-up.
  • b0

    Blower motor not running

    lockout

    IFC commanded the serial ECM and does not see it run.

    • 14-pin harness seated at motor and IFC.
    • Wheel rub, open inductor on 3/4–1 HP motors, dead ECM.
    • Do not install a GR9T96 tap motor.
  • b1

    Blower motor communication

    lockout

    IFC lost serial comms with the circulator.

    • Harness, motor module, IFC serial output.
    • Power-cycle once after the harness is proven. Then motor vs board.
  • b2

    Blower HP / shared-data mismatch

    lockout

    Connected motor horsepower does not match the shared data set.

    • Wrong replacement motor.
    • Memory card / shared data for THIS DM96VC cabinet — a card from a different input or an AMVM97 will b2.
  • d0

    Data not yet on network

    lockout

    Communicating pair is wired and the IFC has no shared data (new board, missing memory card, learn not done).

    • Memory card / ComfortBridge learn for this SKU.
    • Outdoor and Daikin One actually on the bus? d0 on a standalone 24V job means someone enabled communicating when the network is empty.
    • Do not confuse with E0 (ignition lockout).

Workflows

DM96VC vs a 24V Daikin 96%

First minute on site.

  1. Triple 7-seg + serial motor + Daikin One / ComfortNet = this page. Use E/b/d, not AR9T96 E-only.
  2. Single 7-seg E0–E9 + tap motor = Amana AR9T96 / Goodman GR9T96 even if the door says Daikin.
  3. Percent-capacity / modulating valve / AMVM-style cousin = DM97MC. Leave this two-stage page.

No heat on Daikin One

Stat shows a call, furnace idle or E/b/d.

  1. Photograph the triple display and the Daikin One event before touching wires.
  2. Communicating or 24V fallback? That changes every next step.
  3. If communicating: data pair, d0/EE, one master, outdoor crashing the bus.
  4. If 24V fallback: W at the IFC, then E2 trap / E7 igniter / E0 retries as a two-stage 96%.
  5. Motor silent with b0/b1/b2 → harness, shared data, static — not an AR9T96 tap.

E2 / E9 draft on ComfortNet

Inducer runs, no prove, or low only.

  1. E2 is low-fire PS. E9 is high-fire PS. Same hoses as AMVC96, Daikin badge.
  2. Trap and PVC first. Communicating does not fix a drowned collector.
  3. Never tee the two switches. High-fire-only E9 after an E2 ‘fix’ is the high hose.

Test points

Data pair
OEM ComfortNet / Daikin One voltage and polarity. Never 24 VAC between the data pins.
Motor harness
Serial ECM, fully seated. No tap plugs. b2 means the shared data / HP does not match.
Flame rod
µA per this IFC sticker, not the AR9T96 card.
LPS / HPS
Two NO switches, two hoses. E1/E2 vs E8/E9.

Gotchas

  • AR9T96 E-only techs miss b0/b1/b2/d0 and replace the gas valve for a motor/network fault.
  • DM97MC looks identical in the basement and is modulating — staging tests will lie.
  • Amana AMVC96 / Goodman GMVC96 are the factory twins. Same E/b/d set.
  • Daikin One on a GR9T96 24V indoor will never learn. That is a mis-pair, not a bad stat.

Related plates

  • amana-amvc96 — Factory twin. Same ComfortBridge IFC family; Amana badge.
  • daikin-dz20vc — Communicating outdoor HP that belongs on this bus. U4 lives on the outdoor, not this IFC.
  • daikin-dm97mc — Modulating ComfortNet 97% cousin. Same bus, percent capacity, not two-stage E8/E9.