Dimplex Nova Multi-Fire XHD Plug-In Electric Fireboxes Size Guide
Framing dimensions, electrical requirements, and clearances for all four sizes of the Dimplex Multi-Fire XHD series — XHD23, XHD26, XHD28, and XHD33.
Overview
What this guide covers and who it is for
This guide provides the framing dimensions, electrical requirements, and installation constraints for all four sizes of the Dimplex Multi-Fire XHD Plug-In Electric Fireboxes — the XHD23, XHD26, XHD28, and XHD33. Each size is available in two media variants: L (Realogs) with inner-glow logs and pulsing ember bed, and G (Acrylic Crystal) with an Acrylic Ice media bed. The framing dimensions are identical between the L and G variants of each size.
Use this guide to confirm whether the firebox will fit your planned opening before ordering. For a side-by-side comparison of all Dimplex electric fireplace series, see the Dimplex Electric Fireplace Comparison Guide →
Plug-In Format — What This Means for Installation
Key distinction from hardwired built-in fireplaces
The Dimplex Multi-Fire XHD is a plug-in firebox. It requires no gas line, no venting, and no hardwire electrical connection. It plugs into a standard grounded 120V wall outlet — the same type used for appliances throughout your home. This is the defining installation difference from gas inserts and hardwired electric fireplace systems.
Installation Configurations Supported
The installation manual documents three supported installation paths:
- Into a Dimplex mantel — the firebox mounts via screw holes in the mantel side panels.
- Into a custom-built surround or cabinet — secure via front or rear screw hole on the inside face of the firebox. The opening must meet the minimum framing dimensions for the selected size.
- Into an existing fireplace opening (retrofit) — the manual explicitly supports this. When retrofitting, seal all drafts and vents with non-fibrous insulation material. Do not install into an existing opening prone to dampness.
Wall-mount (surface-mounted without an enclosure) and freestanding configurations are not documented in the installation manual.
Outlet Placement
The power cord must be plugged directly into a wall outlet or receptacle. The installation manual prohibits use with extension cords or power strips of any kind. Cord length is not specified in the manufacturer documentation — confirm outlet placement with a qualified electrician before framing the opening to ensure the outlet is accessible after installation without requiring an extension cord.
The outlet wiring must comply with local building codes. The unit uses a standard 3-prong grounded plug for a 120V circuit. No adapter should be used.
⚠ Safety Requirement
Always plug the fireplace directly into a wall outlet or receptacle. Never use an extension cord or relocatable power tap (outlet/power strip). Do not cover or route the power cord under carpeting, rugs, or furniture.
All-Size Comparison
Framing and overall dimensions across all four sizes
XHD23 Framing Width — Source Note
One XHD23L spec sheet table lists a 20-1/2" framing width, while the XHD23 Owner's Manual, the XHD23G spec sheet, and multiple dealer tech specs all state 21-1/2". This guide uses 21-1/2" based on source hierarchy and cross-checked references. Always verify against the physical installation manual before cutting framing.
| Size | Models | Framing W | Framing H | Framing D | Overall W | Overall H | Overall D | Weight |
|---|---|---|---|---|---|---|---|---|
| 23" | XHD23L / XHD23G | 21-1/2" | 20" | 8" | 23" | 20-1/2" | 7-1/2" | 23 lb |
| 26" | XHD26L / XHD26G | 24-3/8" | 18-1/2" | 8" | 26" | 18-7/8" | 7-1/2" | 25 lb |
| 28" | XHD28L / XHD28G | 27" | 23-1/8" | 8" | 27-3/8" | 23-1/2" | 7-1/2" | 32 lb |
| 33" | XHD33L / XHD33G | 31-5/8" | 22-5/8" | 8" | 33-1/8" | 23-1/4" | 7-1/2" | 38.6 lb |
Same dimensions for L and G variants
Framing and overall dimensions are identical between the Realogs (L) and Acrylic Crystal (G) variants of each size. The only difference is the media bed inside the firebox.
Electrical Requirements
All values consistent across all four sizes and both variants
Specifications
Circuit Requirements
A 15 Amp, 120 Volt circuit is required. A dedicated circuit is preferred but not required in all cases. A dedicated circuit will be required if, after installation, the circuit breaker trips or the fuse blows on a regular basis when the heater is operating — additional appliances on the same circuit may exceed the breaker's current rating.
The unit must be plugged into a properly grounded 3-prong outlet. No adapter should be used. Electrical outlet wiring must comply with local building codes and applicable regulations.
Outlet Placement Guidance
Because cord length is not specified in the manufacturer documentation, the outlet must be positioned so the power cord reaches it without requiring any extension. Plan outlet location before framing the opening. The cord must not be routed under carpeting, covered by rugs, or run under furniture or appliances.
No hardwire option
The Multi-Fire XHD is a plug-in only product. Hardwire installation is not documented in the manufacturer installation manual and is not supported.
Clearances & Installation Restrictions
Documented requirements from the installation manual
Documented Clearance Requirements
The installation manual documents the following clearance requirements:
- Rear clearance: At least 1/2" behind the unit for air circulation.
- Beneath the unit: Clearance required for air circulation — do not install directly on carpet or similar surfaces that restrict airflow.
Top, side, bottom (numeric), ceiling, and TV clearance values are not specified in the installation manual. Consult a qualified installer for guidance on TV placement above this firebox.
Outdoor Use
⚠ Prohibited
The installation manual states: "Do not use this firebox outdoors." This product is for indoor use only. It is also not intended for use in bathrooms, laundry areas, or similar indoor locations.
Other Installation Restrictions
- Do not partially or fully cover or obstruct the front of the fireplace — high temperatures may be generated under certain abnormal conditions.
- Do not block air intakes or exhaust openings in any manner.
- Do not insert foreign objects into any ventilation or exhaust opening.
- Do not burn wood or other materials in this firebox.
- Do not use in areas where gasoline, paint, or flammable liquids are used or stored.
- Repairs must be performed by a qualified technician or authorized service agency — do not open the unit.
Mobile Home Approval
Mobile home installation approval is not specified in the manufacturer documentation.
Certifications
All models are cULus listed (file E71416), certified to meet UL Standards. Standards referenced: UL 2021 and CSA C22.2 No. 46-13. FCC Part 15 Class B compliant.
Size-by-Size Reference
All dimensions from the Dimplex installation manual
23" Model — XHD23L / XHD23G
Framing width — source note
One XHD23L spec sheet table lists a 20-1/2" framing width, while the XHD23 Owner's Manual, the XHD23G spec sheet, and multiple dealer tech specs all state 21-1/2". This guide uses 21-1/2" based on source hierarchy and cross-checked references. Always verify against the physical installation manual before cutting framing.
26" Model — XHD26L / XHD26G
28" Model — XHD28L / XHD28G
XHD28G diagram note
The XHD28G spec sheet diagram labels appear transposed versus other models. Framing dimensions (A/B/C) are consistent with all other sources and the Owner's Manual. Verify against the physical installation manual before building the rough opening.
33" Model — XHD33L / XHD33G
Frequently Asked Questions
All answers sourced from the manufacturer installation manual
Does the Dimplex Multi-Fire XHD require hardwiring or a gas line?
No. The Dimplex Multi-Fire XHD is a plug-in electric firebox. It requires no gas line, no venting, and no hardwire electrical connection. It plugs into a standard grounded 120V outlet. The manufacturer requires a 15 Amp, 120 Volt circuit. A dedicated circuit is preferred but not required in all cases — one will be necessary if the breaker trips regularly during operation.
What is the minimum opening depth required for the Dimplex Multi-Fire XHD?
All four sizes of the Dimplex Multi-Fire XHD require a minimum opening depth of 8 inches. The unit itself is 7-1/2 inches deep, and the installation manual specifies at least 1/2 inch of clearance behind the unit for air circulation.
What are the framing dimensions for the 28-inch Dimplex Multi-Fire XHD?
The 28-inch Dimplex Multi-Fire XHD (models XHD28L and XHD28G) requires a minimum opening of 27 inches wide, 23-1/8 inches high, and 8 inches deep. The unit itself measures 27-3/8 inches wide, 23-1/2 inches high, and 7-1/2 inches deep.
Can the Dimplex Multi-Fire XHD be installed into an existing fireplace opening?
Yes. The installation manual explicitly supports retrofit into an existing fireplace opening. When doing so, seal all drafts and vents with a non-fibrous insulation material to prevent chimney debris from falling onto the unit. Do not install into an existing fireplace opening that is prone to dampness.
Can the flame effect run without the heater on the Dimplex Multi-Fire XHD?
Yes. The flame effect and heater operate independently. The manufacturer confirms the unit supports flame-only operation — the flame can be used year-round without activating the heating element. The heater can also be disabled separately via the touch panel controls.