Honeywell Home RC840/U Electromechanical Relay without Transformer
Special Order: typically 2–6 weeks
Ships directly from the manufacturer. This is an estimated lead time, not a guaranteed delivery date.
Availability can change and lead times may be longer. If your project has a deadline, check with us before ordering.
A member of our team will check with the manufacturer and personally reply by email.
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Key Features
- Easy retrofit: direct replacement for brand-name relays to minimize downtime and reduce installation complexity
- Quiet, reliable switching: epoxy soundproofed construction for near-silent operation in occupied spaces
- Labor-saving terminal board: fast, professional installations that cut service time and wiring errors
- Low power draw: allows multiple relays to be controlled by a single thermostat to lower controller costs
- Code-ready confidence: CSA and UL approvals for fire, security and building monitoring applications
Quick Specifications
- Product Model
- RC840/U
- Sector
- Fire
- Brand Name
- Honeywell Home
- Product Line
- Aube
Explore the details
Product information
RC840/U
Overview
Optimize line-voltage control for HVAC and building automation with the Honeywell Home RC840/U electromechanical relay. As an Aube-series relay designed for direct replacement of brand-name units, it simplifies retrofits and reduces downtime while delivering instant activation for precise temperature regulation. The epoxy-coated, sound-dampened design minimizes relay noise—beneficial in commercial offices, security closets and surveillance environments where quiet operation matters.
Built for dependable performance, the RC840/U operates at a minimum of 120V AC and draws low current so a single low-voltage thermostat can manage multiple relays, reducing controller count and wiring complexity. The terminal board connection speeds professional installation and service, saving labor on installs and maintenance. CSA and UL approvals help you meet code and compliance requirements for fire, security and building monitoring systems.
Ideal for HVAC contractors, integrators and facility managers, the Honeywell Home RC840/U provides reliable line-voltage switching for heating loads, access control and security/surveillance integrations. Order now or contact sales for volume pricing and installation support.
Features
- Easy retrofit: direct replacement for brand-name relays to minimize downtime and reduce installation complexity
- Quiet, reliable switching: epoxy soundproofed construction for near-silent operation in occupied spaces
- Labor-saving terminal board: fast, professional installations that cut service time and wiring errors
- Low power draw: allows multiple relays to be controlled by a single thermostat to lower controller costs
- Code-ready confidence: CSA and UL approvals for fire, security and building monitoring applications
| General Information | |
|---|---|
| Sector | Fire |
| Brand Name | Honeywell Home |
| Manufacturer | Resideo |
| Product Line | Aube |
| Product Name | Relay |
| Product Type | Relay |
| Packaged Quantity | 1 |
| Manufacturer Part Number | RC840/U |
| Technical Information | |
| Application/Usage | Control a line voltage resistive load from a low voltage thermostat |
| Physical Characteristics | |
| Color | Black |
| Width | 3.34" |
| Height | 2.87" |
| Power Description | |
| Minimum Operating Voltage | 120V AC |
| Product Information | |
| Installation Type | Professional Install |
| Miscellaneous | |
| Features | Direct replacement for any brand name relay, Epoxy soundproofed relay ensures quiet operation, Immediate relay activation provides improved temperature control and comfort, Low current consumption means multiple relays can be controllers by a single thermostat, Terminal board connection enables easy installation |
| Certifications & Standards | CSA Approved, UL Approved |
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Plan your purchase
Is this right for your project?
Confirm the model, required accessories and delivery needs before ordering.
- SKU:
- RC840U
- Manufacturer part:
- RC840/U
How do I confirm compatibility?
Check the specifications and manufacturer documents for your existing system. Send us your model numbers and project requirements if you need help selecting equipment or accessories.
Ask a product specialistWhen will this item ship?
Availability is shown above. Special-order items and project quantities may need additional lead time. Contact us to confirm a delivery date before scheduling installation.
Shipping, freight and delivery detailsWhat should I know about returns?
Returns require an approved RMA. Consult the linked return policy for deadlines and eligibility. For standard non-defective returns, eligible factory-sealed items carry a 15% restocking fee and customer-paid return shipping; open-box and used items are refused. Defective and DOA claims follow the policy's separate terms. Special orders and other exclusions are final sale.
Read return eligibility and exclusionsHoneywell Home RC840/U Electromechanical Relay without Transformer
RC840/U