Honeywell to Resideo Part Number Cross-Reference

If you are holding an older manual, a service tag, or a parts list that says Honeywell and you cannot find the part under that name, this page explains what happened and how to find it.

What changed, and what did not

Honeywell completed the spin-off of Resideo Technologies on 29 October 2018. The Honeywell Homes product portfolio went to Resideo as a stand-alone company, and Honeywell licensed the Honeywell Home brand to Resideo under a long-term agreement. That is why the brand still appears on the box while the company behind it is Resideo.

The practical consequence for anyone ordering parts: the model numbering carried over. Across the 606 Resideo parts we stock, the numbers follow the same historic Honeywell series they always did. An L8148E aquastat relay is still listed as an L8148E. A VR8345Q universal gas valve is still a VR8345Q. A ZD zone damper is still a ZD.

So the number in your old manual is almost always the number to order. You are not looking for a replacement part — you are looking for the same part with a different company name on the label.

Part number series index

Every Honeywell control series we carry, what it covers, and where it sits in the catalog.

Hydronic controls

Series	What it is	Example	Where to find it
L	Aquastat relays, limit controls	L8148E1299	Aquastats and wells, fan and limit controllers
V	2-way zone valves, radiator valves	V8043, V110D1016	2-way zone valves, thermostatic radiator valves
VC / VU	Zone valve powerheads, fan coil valves	VC8110ZZ32, VU844A1060	Replacement heads, fan coil zone valves
VCZZ	Zone valve internal parts	VCZZ7100	Zone valve parts
AM	Thermostatic mixing valves	AM100-002RP	Mixing valves
DS / K	Pressure reducing and fill valves	DS06-105-SUT-LF	Pressure reducing valves
PV / HS	Air separators, hydraulic separators	PV150P	Air separators
TK	Boiler trim kits	TK30PV125SNK	Boiler trim kits

Gas and ignition

Series	What it is	Example	Where to find it
VR / SV	Gas valves and gas controls	VR8345Q4563, SV9641M4510	Gas valves
Q	Pilot assemblies, thermocouples, ignition components	Q4100C9068	Gas ignition components, thermocouples
S	Ignition control modules	S8910U3000	Gas ignition components
R	Oil burner primary controls	R8184G	Oil burner controls

Zoning and switching

Series	What it is	Example	Where to find it
ZD / ARD	Rectangular and round zone dampers	ZD8X20TZ, ARD7TZ	Zone dampers
HZ	Forced air zone panels	HZ322	Forced air zone panels
HPZC / HPSR	Zone valve controllers, switching relays	HPZC106	Switching relays
R	Fan centers, general purpose relays	R8285A1048, R841D1036	Relays
AT	Low-voltage transformers	AT150F1022	Transformers
DP	Definite purpose contactors	DP3040C5001	Contactors

Thermostats and air

Series	What it is	Example	Where to find it
TH	Current thermostat line — T3, T4, T6 Pro and PRO series	TH3110U2008, TH114-A-240D-B	Thermostats
T / TL	Legacy and line-voltage thermostats	T812A1010	Non-programmable, line voltage
THP / C	RedLINK accessories, sensors	C7735A1000	Thermostat accessories
F / FC	Media air cleaners and filters	FC40R1029	Air cleaners and filters
HC / HM	Humidifier pads and units	HC26E1004	Humidifiers and dehumidifiers
VWS	Water leak detection and shutoff	VWS1000	Leak detection valves

Where the number genuinely does change

The rebrand did not renumber parts, but parts do get superseded over time, and that happens independently of what is written on the box. Two cases to watch:

Gas valves and ignition assemblies. These are matched to the appliance and often to a serial range within a single model, because the manufacturer revises the component without changing the appliance name. Order from the data plate on the equipment, not from the model name of the furnace or boiler.

Discontinued controls with a functional replacement. Where an older control is no longer produced, the replacement usually differs in more than the number — terminal layout, switch action or voltage may change. Confirm the specification rather than assuming a drop-in.

Two checks before you order

Voltage. Low-voltage 24V controls drive a system through a transformer and relay and cover most gas and hydronic equipment. Line voltage switches 120V or 240V directly and belongs to electric baseboard and radiant. Connecting one to the wrong system is a fire risk, not a malfunction.

Aquastat and well together. An aquastat has to be paired with the correct immersion well, seated to the bottom with conducting paste. Well length and bulb diameter have to match, or the control reads the air in the well and responds late.

The full range is in the Resideo collection — over 600 controls and parts in stock.