AI Summary
A disconnect box is a required safety device that allows power to be shut off to the outdoor heat pump unit without accessing the main electrical panel. Building codes require it to be within sight of the unit for service safety. Installation costs $150-300 and should be included in every heat pump quote.
What Is a Disconnect Box in Heat Pump Installs?
Heat pump quotes should include a disconnect box, but some don't mention it explicitly. This guide explains what disconnect boxes do, why they're required, and what to look for in quotes.
What a Disconnect Box Is
A disconnect box (also called a disconnect switch or service disconnect) is an electrical safety device installed near the outdoor heat pump unit. It allows power to be shut off locally without going to the main electrical panel.
The disconnect contains a switch or pull-out fuse block that completely cuts power to the unit. Service technicians use it to safely work on the equipment.
Why Disconnect Boxes Are Required
Code Requirement
National Electrical Code (NEC) requires a disconnect within sight of HVAC equipment. "Within sight" typically means visible from the unit and not more than 50 feet away. Local codes may have additional requirements.
Service Safety
Technicians need to shut off power before servicing equipment. Having the disconnect at the unit is safer and more convenient than requiring someone to hold the breaker at the panel during service.
Emergency Shutoff
In emergencies, the disconnect allows immediate power shutoff without accessing the electrical panel. This is important if the unit is damaged or malfunctioning.
Disconnect Box Types
- Pull-out fuse type: Contains cartridge fuses that are pulled out to disconnect power
- Switch type: Has a handle that switches between on and off positions
- Weatherproof enclosure: NEMA-rated box designed for outdoor installation
Most residential heat pump installations use 30-60 amp disconnect boxes depending on unit size.
Where Disconnect Boxes Are Located
Disconnects are typically mounted on the house wall near the outdoor unit or on a post adjacent to the unit. They must be:
- Within sight of the equipment
- Readily accessible (not blocked by plants or structures)
- At appropriate height (typically 4-6 feet above ground)
- Protected from physical damage
What's Included in Installation
Disconnect box installation includes:
- Weatherproof disconnect enclosure
- Appropriate amperage rating for the unit
- Mounting hardware
- Conduit and wire from disconnect to unit (whip)
- Proper grounding
The disconnect connects to the circuit breaker at the main panel via underground or overhead wiring, then to the heat pump via flexible conduit (whip).
Installation Cost
Disconnect box installation typically costs $150-300 including materials and labor. This covers the disconnect enclosure, mounting, and connection to the unit.
Cost may be higher if:
- Longer conduit runs are needed
- Mounting location requires special hardware
- Local code requires specific disconnect type
- Existing disconnect needs replacement or relocation
How Quotes Handle Disconnects
"Electrical Work Included"
This vague language may or may not include the disconnect. Ask specifically whether disconnect installation is part of electrical work.
"Disconnect Box Included"
Clear language indicating the disconnect is part of the quoted scope. This is what you want to see.
No Mention of Disconnect
Some quotes don't mention the disconnect at all. This doesn't necessarily mean it's excluded, but clarification is needed.
"Disconnect If Required"
Suggests the contractor will determine necessity during installation. Since disconnects are code-required, this language is unclear.
Red Flags
Be cautious if:
- Quote explicitly excludes disconnect installation
- Contractor suggests skipping the disconnect
- Quote says "disconnect if needed" (it's always needed)
- Electrical work is listed as "TBD" or "additional"
Proper installations always include code-required disconnects.
Questions to Ask
- Is disconnect box installation included in this quote?
- What type of disconnect will be used?
- Where will the disconnect be located?
- Is the disconnect included in "electrical work" or listed separately?
- Does the installation meet local electrical code requirements?
Check What Your Quote Says About Electrical Work
See whether your quote explicitly includes disconnect box installation.
Decode Your Quote →Why This Matters
Disconnect boxes are code-required safety devices that should be included in every heat pump installation. Quotes that don't mention them may be incomplete or may assume you understand they're included.
Clarifying disconnect inclusion prevents surprise costs during installation and ensures your installation meets electrical code requirements.