Patterson-Kelley NURO boiler controller

Register map(s) for this device, each at the trust rung it earned. Addresses are 0-based as on the wire. Word order and scaling are confirmed at the hardware-verified rung and at no rung below it.

interop-verified

Read + decoded cleanly over a real network vs an independent third-party Modbus test server (transport and framing; reads are remapped into the server's register window, so the map's own addresses are NOT exercised). Does NOT prove word order/scaling against the actual device.

point	address (0-based)	type	scale	unit
outlet_temperature	100	I16	0.1	°C
inlet_temperature	101	I16	0.1	°C
stack_temperature	102	I16	0.1	°C
dhw_temperature	103	I16	0.1	°C
header_temperature	104	I16	0.1	°C
hx_temperature	105	I16	0.1	°C
oda_temperature_filtered	106	I16	0.1	°C
extra_field_temperature	107	I16	0.1	°C
wireless_temperature_oda	108	I16	0.1	°C
analog_input	109	U16	0.1	mA
analog_output	110	U16	0.1	mA
burner_control_digital_io	111	U16	1
burner_control_digital_io_2	112	U16	1
ch_mode_active_setpoint	113	I16	0.1	°C
dhw_mode_active_setpoint	114	I16	0.1	°C
demand_source	130	U16	1
active_demand_status	131	U16	1
boiler_state	132	U16	1
flame_signal	133	U16	0.01	V
fan_speed	134	U16	1
firing_rate	135	U16	0.5	%
error_code	136	U32BE	1
error_type	138	U16	1
burner_control_cycle_count	151	U32BE	0.1
burner_control_run_time	153	U32BE	0.1	hours
bms_heartbeat	170	U16	1
ch_boiler_control	171	U16	1
bms_ch_setpoint	172	I16	0.1	°C
bms_ch_demand	173	U16	1
bms_header_temperature	174	I16	0.1	°C
bms_oda_temperature	175	I16	0.1	°C
bms_analog_input	176	U16	0.1	mA
dhw_boiler_control	191	U16	1
bms_dhw_setpoint	192	I16	0.1	°C
bms_dhw_tank_setpoint	193	I16	0.1	°C
bms_dhw_demand	194	U16	1
bms_dhw_temperature	195	I16	0.1	°C

link settings as documented (unverified): RTU; baud 9600/19200/38400; FC 03,06; Physical Layer: RS 485 (two wire). Data Length: 8.

bench facts as documented (unverified)

terminals	TB1, TB2
termination	End of Line Termination Resistor Jumper at Location 9 (MODBUS)
wiring notes	Cascade Bias Jumpers at Location 4 (Ground Bias) and Location 5 (VCC Bias) on master boiler.
inter-frame delay	20 ms
protocol notes	When a RESERVED address is read, it will return an illegal/invalid address.
identification notes	Software Revision: 02.40.00
doc revision	1004905979 - Rev. H
firmware applicability	02.40.00

field reports — community-sourced, unverified (checked 2026-06-11)

confirmed: Baud rates (9600, 19200, 38400), framing (RTU), function codes (3, 6), and parity (N) — confirmed by Patterson-Kelley NURO Boiler Controller Advanced User's Guide (1004905979 - Rev. H)
confirmed: Physical layer details including Cascade Bias Jumpers at Location 4 and 5, and End of Line Termination Resistor Jumper at Location 9 — confirmed by Patterson-Kelley NURO Boiler Controller Advanced User's Guide (1004905979 - Rev. H)
confirmed: Register map addresses (e.g., outlet_temperature @ 100, inlet_temperature @ 101, stack_temperature @ 102, bms_heartbeat @ 170, ch_boiler_control @ 171) — confirmed by Patterson-Kelley NURO Boiler Controller Advanced User's Guide (1004905979 - Rev. H)

The trust ladder

Each rung states what it proved and what it did not. Gray until proven; green is earned by hardware only.

generated — A prompt produced it. Unproven — anyone can regenerate this.
structure-verified — Decode path is structurally sound (addresses, widths, finite values). Does NOT prove word order or scaling.
interop-verified — Read + decoded cleanly over a real network vs an independent third-party Modbus test server (transport and framing; reads are remapped into the server's register window, so the map's own addresses are NOT exercised). Does NOT prove word order/scaling against the actual device.
simulator-verified — Decoded correctly against a protocol emulator seeded with known-true values — catches word-order/scaling errors vs the emulator, not the physical device.
hardware-verified x1 — Matched a real device with operator-attested readings as ground truth — the only rung that confirms word order + scaling on the wire.

If your device isn't here, upload its register map. Generation is free, and the connector keeps the rung it earns under testing.

To prove a connector against your own device, order hardware verification. If it doesn't verify, you don't pay.

Platform builders can license the verified library: machine-readable maps, the firmware matrix, API access.