FieldBench
Wiring

ComfortBridge modulating furnace

1 / 2 · percent fire

1 / 2 · percent fire

AMVM97 / GMVM97 / ARVM97 / DM97MC. Same 1/2 pair as two-stage ComfortBridge. Capacity is 0–100%, not W1/W2.

Written circuit description only — FieldBench does not redraw maker schematics. Example: R to W closes on a heat call; verify 24V at W1 before you change the IFC.

Open manufacturer PDF

Heat sequence

  1. 1Power. L1 / N → IFC120V
  2. 2Call. Data pair or 24V W → IFCBus or 24V
  3. 3Draft. IFC → inducer → proveTwo-stage PS or a pressure band
  4. 4Ignite. IFC → HSI → valve120V igniter
  5. 5Blow. IFC → serial ECMNo tap, no cap

Communicating modulating

ComfortBridge / ComfortNet indoor with a modulating valve.

Modulating IFC

No W2 high-fire prove. Percent request on the bus.

  • 1DataData
  • 2DataData
  • R24V24V
  • CCommon24V

Landing

  • DataControlIFC 1/2outdoor 1/2

    Data. Fire rate is serial.

IFC harness — modulating

Call arrives on the data pair (or 24V W). Gas train is still inducer / prove / igniter / valve.

Transformer + fuse

24V still exists for accessories and for a 24V outdoor. Data pair is not the transformer.

  • L1 / N120VLine
  • R / C24V strip24V
  • FUSEOn the IFC24V

24V safety chain

Limit / rollout / door still open the heat path. Codes are on THIS IFC language.

  • DOORInterlock24V
  • LIMITMain limit24V
  • ROLLOUTManual reset24V

Variable inducer + pressure band

Inducer ramps to a pressure band. There is no discrete 32 / E9 high-fire switch.

  • INDVariable inducer from the IFCLine
  • BANDPressure transducer / band — not LPS vs HPS24V

HSI + modulating valve

Capacity is a percent on the bus. There is no W2 solenoid to chase.

  • HSI120V igniterLine
  • VALVE %Serial / percent valve24V
  • FLAMEµA DC24V

Serial variable-speed ECM

IFC talks to the motor on the serial harness. No F-taps. No dual run cap on this blower.

  • SERIALIFC-to-motor harness. Unplugged motor = CFM / comm fault, not a tap problem24V
  • CFMSet in the IFC menu / model plug / CoolCloud — not a dip switch on most of these24V

Landing

  • LineCallIFCinducerprove

    Band, not a single PS

  • LineIFCHSIvalve

    120V igniter, 24V or serial valve

  • 24VFlame rodIFC

    µA DC

  • DataIFCserial blower

    No F-taps. No PSC cap.

Prove it

  • CoolCloud / Daikin One shows percent capacity, not Ht1/Ht2.

Do not

  • Do not apply AR9T96 / AMVC96 two-stage staging tests.
  • Do not land W on a random terminal to force it.

Same published 1/2 pair. The valve is the difference.

Plates on this landing