The Honeywell Home 10-Way Junction Box (model 42002116-002) is a compact, universal wiring accessory designed to simplify the wiring of Sundial Plan central heating installations. Compatible with both basic boilers and those with built-in pump overrun, it provides a tidy, centralised connection point for heating control wiring in place of multiple in-line joints.
Designed to be used alongside the numbered wiring diagrams in the Honeywell Home Wiring Guide, this is a genuinely universal box suitable for any 15 amp rated wiring application. A strong, fire-retardant ABS enclosure with cable clamps and strain relief on all entries keeps connections secure and compliant with current UK Wiring Regulations.
10
Terminals
15A
Rated Wiring Application
230V
Max Terminal Voltage
12
Cable Entry Knockouts
Fire-Retardant ABS
Enclosure Material
147 x 105 x 40mm
Dimensions
Qualified Electrical Installation Required
This junction box carries 230V mains wiring as part of a central heating control circuit. Installation must be carried out by a qualified electrician or heating engineer in accordance with current UK Wiring Regulations.
Use Alongside the Honeywell Wiring Guide
This junction box is designed to be used in conjunction with the numbered wiring diagrams in the Honeywell Home Wiring Guide, which details the correct wiring termination for a range of Sundial Plan system layouts.
Universal Application
As a universal wiring box rather than a dedicated Sundial Plan wiring centre, this product can be used across a wide range of 15A-rated wiring applications - not limited to Sundial Plan systems alone. Confirm it matches your specific installation requirements before use.
Simple, Centralised Wiring
A dedicated 10-terminal junction box gives a clean, centralised point to join and route heating control cabling, reducing the need for multiple in-line connectors.
Fire-Retardant ABS Enclosure
The strong, fire-retardant ABS housing protects connections and adds a layer of safety margin in the event of an electrical fault.
Flexible Cable Entry
12 knockouts positioned around all sides of the box allow cables to enter from whichever direction suits the installation, simplifying routing in tight spaces.
Secure Cable Management
Integrated cable clamps accept cable up to 8 mm² and provide strain relief, keeping connections secure and reducing stress on terminals over time.
Universal 15A Rating
Rated for 15 amp, 230V, 50Hz applications, making it suitable across a broad range of central heating wiring scenarios beyond a single system type.
Compliant & Approval-Ready
Designed to enable compliance with electrical approvals and wiring specifications, helping installations meet current UK Wiring Regulations.
General
Model / MPN
42002116-002
Product Type
10-way universal junction box
Compatible Systems
Sundial Plan central heating installations; universal 15A wiring applications
Enclosure Material
Fire-retardant ABS
Colour
White
Electrical
Number of Terminals
10
Maximum Current of Terminals
15 A, 230 V, 50 Hz
Cable Clamp Capacity
Up to 8 mm² cable
Cable Entries
12 knockouts around all sides
Mechanical
Dimensions (W x H x D)
147 x 105 x 40 mm
Fixing
6 fixing holes in base for No. 8 screws
Compliance
Current UK Wiring Regulations
Warranty
Manufacturer Guarantee
1 year
What is this junction box used for?
It's designed to simplify the wiring of Sundial Plan central heating installations, giving a centralised, tidy connection point for control wiring, compatible with basic boilers and those with pump overrun.
Does it work with any heating system, or only Sundial Plan?
It's a universal box rated for any 15 amp wiring application, so while it's commonly used with Sundial Plan systems, it isn't restricted to them - always confirm it suits your specific installation.
How many cables can enter the box?
The enclosure has 12 knockouts positioned around all sides, giving flexibility to route cables in from whichever direction best suits the installation.
What size cable does it accept?
The integrated cable clamps accept cable up to 8 mm², with strain relief to keep connections secure.
Is a wiring diagram included?
The box itself doesn't include a diagram, but it's designed to be used alongside the numbered wiring diagrams in the Honeywell Home Wiring Guide, which is available separately from Honeywell.
BTU & WATT Calculator
Room Dimensions
Room Type
Living Room
Bedroom
Kitchen
Bathroom
Conservatory
Hallway
Glazing Type
Single Glazed
Double Glazed
Triple Glazed
External Walls
0 Wall
1 Wall
2 Walls
3 Walls
4 Walls
Insulation Level
Poor
Average
Good (New Build)
Required Heating
0
Watts
0
BTUs
Documentation
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