Resideo · Honeywell Home Brand · Spun off from Honeywell 2018 · Scottsdale, AZ

Resideo / Honeywell Home —
Aquastats, Ignition Controls, Pilot Burners & Thermostats

Memphis Control Center stocks Resideo controls — sold under the Honeywell Home brand — for residential and commercial HVAC and hydronic heating systems. Aquastat controllers (L4006, L4008, L6006, L6008, L4081 series) for boiler high-limit, low-limit, and circulator control. Well assemblies (121371A, 121371B, 121371AA) for immersion sensing. Ignition modules (S8610U universal intermittent pilot, S87B direct spark). Pilot burners (Q345U1005, Q345A1313, Q314A4586). Hot surface igniters (Q4100C series). Thermostats (T498B1512 electric heat, T834L low-volt). AT140A1000 120V/24V transformer for HVAC low-voltage power. Family-owned, serving Memphis since 1967.

Browse All Resideo Products Call (901) 458-2000
Honeywell Home Brand Aquastats · Ignition · Pilot Burners L4006 · L4008 · L6006 · S8610U Thermostats · Well Assemblies Family-Owned Since 1967
Honeywell Home HeritageResideo was spun off from Honeywell in 2018 and manufactures under the Honeywell Home brand — the same controls legacy dating back to Honeywell's founding in 1885
Aquastat Cross-Reference HelpHave an old Honeywell Aquastat model number? Call (901) 458-2000 — we'll identify the current Resideo/Honeywell Home replacement. The L4006, L4008, L6006, and L6008 series are direct continuations of the classic Honeywell Aquastat line
Ignition & Pilot OEM PartsS8610U universal intermittent pilot module, Q345 pilot burners, Q4100C hot surface igniters, S87B direct spark — the ignition components most commonly needed on Honeywell-equipped furnaces and boilers
Same-Day ShippingResideo / Honeywell Home controls ship same day from Memphis, TN — free. Call (901) 458-2000 with your model number and we'll confirm availability
Resideo Technologies — the Honeywell Home spinoff. On October 29, 2018, Honeywell completed the tax-free spin-off of its Homes and ADI Global Distribution businesses as Resideo Technologies, Inc. (NYSE: REZI), headquartered in Scottsdale, Arizona. Resideo manufactures and distributes home comfort, security, and safety products under a long-term exclusive license of the Honeywell Home brand. This means the Aquastat controllers, ignition modules, thermostats, and heating controls that were previously sold as "Honeywell" are now manufactured and sold by Resideo under the Honeywell Home brand — the same products, same part numbers, same quality, different corporate parent. Resideo had approximately $6.76 billion in revenue in 2024 and products in over 150 million homes. The ADI Global Distribution division is Resideo's wholesale distribution arm for security and low-voltage products.

Resideo / Honeywell Home Product Lines at Memphis Control Center

Memphis Control Center stocks Resideo controls across three categories: Aquastat controllers and well assemblies, ignition controls and pilot burners, and thermostats. Contact us or call (901) 458-2000 with your model number.

Aquastats Aquastat Controllers — L4006, L4008, L6006, L6008, L4081 Series

Resideo / Honeywell Home Aquastat controllers are immersion or remote-bulb temperature controllers for hydronic heating systems — boilers, storage tanks, and piping. They provide high-limit shutoff (prevents overheating), low-limit control (maintains minimum temperature for tankless coil systems), and circulator control. L4006 series — immersion type with copper bulb, 100–240°F. L4008 series — remote bulb immersion type, high or high-limit/manual reset. L6006 series — SPDT contacts for circulator + high/low limit. L6008 series — remote bulb SPDT, circulator and low-limit. L4081 — high/low limit combination.

ModelTypeRangeContactsShop
L4006A1967Immersion · hi/lo limit100–240°FSPDTShop
L4006A1678Immersion · hi/lo limit100–240°FSPSTShop
L4006E1067Immersion · high limit · manual reset130–270°FSPSTShop
L6006A1145Immersion · hi/lo limit · circulator100–240°FSPDTShop
L6006C1018Strap-on · hi/lo · circulator65–200°FSPDTShop
L4008A1015Remote bulb · hi/lo limit100–240°FSPST · 66" cap.Shop
L4008A1130Remote bulb · hi/lo limit130–270°FSPST · 10' cap.Shop
L4008E1040Remote bulb · high limit · manual reset130–270°FSPST · 66" cap.Shop
L4008E1156Remote bulb · high limit · manual reset130–270°FSPST · 66" cap.Shop
L4008E1305Remote bulb · high limit · manual reset100–240°FSPST · 66" cap.Shop
L6008A1192Remote bulb · hi/lo · circulator100–240°FSPDT · 66" cap.Shop
L4081A1023Immersion · hi/lo combination110–240°FSPSTShop
L4006 · L4008 · L6006 · L6008 · L4081 High Limit · Low Limit · Circulator SPST · SPDT Immersion · Remote Bulb · Strap-on Auto & Manual Reset 65°F–270°F Range
Well Assemblies Aquastat Well Assemblies — 121371A, 121371B, 121371AA

Resideo / Honeywell Home well assemblies are copper immersion wells that thread into a boiler or pipe tapping and accept the Aquastat sensing bulb. Required when the boiler or system pipe does not have a direct immersion tapping — the well creates the tapping and protects the bulb from direct fluid contact. 121371A — 1/2" NPT, 3" insertion, copper. 121371B — 3/4" NPT, 3" insertion, 1-1/2" insulation depth, copper. 121371AA — well clamp assembly with clamp capillary for strap-on surface mounting (for use with L6006C and similar strap-on Aquastats).

ModelDescriptionNPTInsertionShop
121371ACopper well assembly1/2"3"Shop
121371BCopper well assembly · 1-1/2" insulation3/4"3"Shop
121371AAWell clamp assembly with clamp capillary — strap-on——Shop
121371A · 121371B · 121371AA 1/2" NPT · 3/4" NPT 3" Insertion · Copper Strap-on Clamp Option
Ignition Controls Ignition Modules — S8610U, S87B · Pilot Burners — Q345, Q314 · HSI — Q4100C

Resideo / Honeywell Home ignition controls for residential and light commercial furnaces and heating appliances. The S8610U3009 is the universal intermittent pilot module — one of the most widely used ignition controls in the industry. It configures for 15- or 90-second ignition trial, with or without prepurge, single or two-rod flame sensing, compatible with natural or LP gas. Replaces over 400 White-Rogers, Robertshaw, Johnson Controls, and UTEC (HSC) intermittent pilot ignition modules. The S87B1016 is a direct spark ignition (DSI) module for gas burners. The Q345U1005 universal pilot burner replaces most standing and intermittent pilot assemblies. The Q4100C series are silicon carbide hot surface igniters.

ModelTypeDescriptionShop
S8610U3009Ignition moduleUniversal intermittent pilot · 24V · configurable trial 15 or 90 sec · NG/LPShop
S87B1016DSI moduleDirect spark ignition · 24V · 0.8-sec flame failure · 11-sec lockout · NG/LPShop
Q345U1005Pilot burnerUniversal intermittent pilot · adjustable tip · NG/LP · 1/4" & 1/8" compressionShop
Q345A1313Pilot burnerNatural gas · B bracket · single tip left · BCR-18 orificeShop
Q345A1305Pilot burnerNatural gas · B bracket · BCR-18 orifice — replaced by Q345U1005Shop
Q314A4586Pilot burnerStanding pilot · NG/LP · front single tip · BCR-18 & BBR-10 orifices · B bracketShop
Q4100C9056Hot surface igniter120V · silicon carbide · 5-1/4" leads · rib offset left · 392°F · NG/LPShop
Q4100C9050Hot surface igniter120V · silicon carbide · 11" leads · rib on right · 3 brackets · NG/LPShop
AT140A1000Transformer120V input / 24V output · HVAC low-voltage power supplyShop
S8610U Universal IPI Module S87B Direct Spark Q345 Pilot Burners Q4100C Hot Surface Igniters 24V · 120V NG & LP Gas
Thermostats Thermostats — T498B1512, T834L1004

Resideo / Honeywell Home thermostats for electric heat and low-voltage HVAC systems. The T498B1512 is a line-voltage electric heat thermostat for electric baseboard, convector, and fan-forced heaters — DPST, 22A at 120/208/240V and 19A at 277V, bimetal sensor, 40–80°F range, vertical mount, brush gold finish, includes locking cover. The T834L1004 is a low-voltage mercury-free thermostat for single-stage cool systems.

ModelTypeDescriptionShop
T498B1512Line voltageElectric heat thermostat · DPST · 22A · 120/208/240/277V · 40–80°F · bimetal · verticalShop
T834L1004Low voltageMercury-free thermostat · single-stage cool · low voltageShop
T498B — Electric Heat T834L — Low Voltage Line Voltage & Low Voltage Mercury-Free

Most-Ordered Resideo / Honeywell Home Products

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S8610U3009Universal IPI module · 24V 121371AWell assembly · 1/2" NPT · 3" copper 121371BWell assembly · 3/4" NPT · 3" copper 121371AAWell clamp assembly · strap-on L6006C1018Strap-on aquastat · 65–200°F · SPDT L6006A1145Aquastat · 100–240°F · SPDT · circulator L4006A1967Aquastat · 100–240°F · SPDT L4006A1678Aquastat · 100–240°F · SPST L4008E1040Aquastat · 130–270°F · manual reset L4008E1305Aquastat · 100–240°F · manual reset L4008E1156Aquastat · 130–270°F · manual reset L4008A1015Aquastat · remote bulb · 66" cap. L4081A1023Aquastat · hi/lo combo · 110–240°F Q345U1005Universal pilot burner · NG/LP Q345A1313Pilot burner · NG · BCR-18 Q314A4586Standing pilot burner · NG/LP Q4100C9056Hot surface igniter · 120V · 5-1/4" leads Q4100C9050Hot surface igniter · 120V · 11" leads T498B1512Electric heat thermostat · 22A · line V AT140A1000Transformer · 120V/24V · HVAC S87B1016Direct spark ignition · 24V All Resideo →Browse all Resideo / Honeywell Home products

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Frequently Asked Questions — Resideo / Honeywell Home Controls

Common questions from HVAC technicians, plumbing and heating contractors, and boiler service professionals about Resideo Aquastats, ignition controls, and pilot burners. Contact us or call (901) 458-2000 with your model number.

What is the difference between Resideo and Honeywell?

Resideo Technologies, Inc. was spun off from Honeywell International as an independent publicly traded company (NYSE: REZI) on October 29, 2018. Resideo manufactures and sells the same heating, cooling, and home comfort controls under a long-term exclusive license of the Honeywell Home brand. The controls — Aquastats, ignition modules, pilot burners, thermostats — are the same products as the former Honeywell Home and Heating lines, now made and sold by Resideo. Part numbers remain the same. You may see "Resideo," "Honeywell Home," or both on the packaging — they are the same company and same product.

What does an Aquastat controller do?

An Aquastat is an immersion or remote-bulb temperature controller for hydronic heating systems. It monitors boiler water temperature and controls the burner and/or circulator based on setpoints. High-limit function: shuts off the burner if water temperature exceeds a safe maximum — prevents overheating and boiler damage. Low-limit function: keeps boiler water at a minimum temperature for tankless domestic hot water coils — the boiler fires to maintain temperature even when there's no heating call. Circulator control: SPDT contacts on L6006/L6008 models start and stop the circulator pump based on temperature. Resideo's L4006, L4008, L6006, and L6008 series cover all of these functions in various configurations.

What is the difference between the L4006, L4008, L6006, and L6008 Aquastats?

L4006 series: immersion type with 3/8" × 2-7/8" copper bulb, mounts directly in a boiler tapping. SPST (L4006A1678) or SPDT (L4006A1967) contacts. L4008 series: remote bulb — the sensing bulb is at the end of a capillary that extends away from the control body, used when direct mounting isn't possible. L6006 series: SPDT contacts designed for combined circulator control and high/low limit. L6008 series: remote bulb version of the L6006 with SPDT contacts. In short: L4006/L4008 are high or low limit; L6006/L6008 add dedicated circulator control. L4006/L6006 are immersion (direct mount); L4008/L6008 are remote bulb (capillary).

What does the S8610U3009 universal intermittent pilot module do?

The S8610U3009 is a universal intermittent pilot ignition control module for gas furnaces and heating appliances. It controls the ignition sequence: sparks the pilot, proves the pilot flame via flame sensing rod, then opens the main gas valve. If the pilot doesn't light within the trial period, it locks out. The S8610U3009 is configurable for 15-second or 90-second ignition trial, with or without 30-second prepurge, single or two-rod flame sensing, compatible with natural or LP gas. It replaces a wide range of older Honeywell S86 and S8610 series modules and is one of the most widely stocked ignition controls in the industry.

What is the difference between Q345A1305, Q345A1313, and Q345U1005 pilot burners?

Q345A1305: natural gas only, B bracket, BCR-18 orifice — replaced by Q345U1005 (still available while supply lasts). Q345A1313: natural gas only, B bracket, BCR-18 orifice, tip directed left — still active. Q345U1005: universal replacement compatible with NG and LP gas, adjustable tip, 1/4" and 1/8" compression fittings, U-style bracket. The Q345U1005 is the current recommended replacement for most Q345 series pilots. Call (901) 458-2000 with your old pilot part number and we'll confirm the correct replacement.

How do I select the right Aquastat well assembly?

Select by NPT thread size and mounting type. 121371A: 1/2" NPT, 3" insertion, copper — for boiler tappings with 1/2" pipe thread. 121371B: 3/4" NPT, 3" insertion, 1-1/2" insulation depth, copper — for 3/4" tappings common on larger boilers. 121371AA: well clamp assembly for strap-on surface mounting — used with L6006C and similar strap-on Aquastats that don't require a pipe tapping. No tapping available on the boiler? Use the 121371AA strap-on clamp. Have a pipe tapping? Match the NPT size (1/2" → 121371A, 3/4" → 121371B).

Need Help Finding a Resideo / Honeywell Home Part?

Call us with your model number — Aquastat, ignition module, pilot burner, or thermostat. We'll confirm availability and same-day shipping from Memphis, TN.

Call (901) 458-2000 Browse All Resideo Products Contact Us

For emergencies, outside of business hours, call #901-604-7069