Modern Flames Spectrum Slimline Size Guide
Finished opening dimensions, electrical requirements, and clearances for the SPS-50B, SPS-60B, SPS-74B, and SPS-100B — everything needed to frame and wire the installation correctly.
Overview
All dimensions from the Modern Flames installation manual
The Spectrum Slimline is a recessed flush-mount or wall-mount electric fireplace available in four sizes: 50", 60", 74", and 100". The recessed installation depth matches a standard 2x4 stud wall — the minimum finished opening depth is 4 inches across all four models.
This guide covers the finished opening dimensions required to frame the wall cavity, the overall unit dimensions, electrical circuit requirements, and all clearance-to-combustibles values. Use these values to plan the framing, electrical rough-in, and finish material before the unit arrives.
- Installation types supported: Recessed (flush-mount into framed wall opening), wall-mount (surface bracket), and mantel-mount
- Minimum finished opening depth: 4" (102mm) — all four sizes
- Overall unit depth: 4-3/4" (121mm) — all four sizes
- Electrical: 120V, dedicated 15A circuit, plug-in or hard-wire
- Outdoor use: Prohibited. Indoor use only.
Not doing your own framing?
Send this page to your installer — they will know exactly how to use it. The key numbers they need: minimum wall depth is 4", the framing height is 16-1/4" for all four sizes, and a dedicated 15-amp circuit is required. Everything else on this page is for them.
Finished Opening Dimensions
All dimensions from the Modern Flames installation manual
The table below shows the finished opening required in the wall for each model — the dimensions of the hole the unit slides into after finish material is applied. The depth of 4" minimum applies to all sizes and is compatible with a standard 2x4 stud wall.
| Model | SKU | Framing W | Framing H | Framing D (min) | Overall W | Overall H | Overall D |
|---|---|---|---|---|---|---|---|
| 50" | SPS-50B | 48-7/8" | 16-1/4" | 4" min. | 49-3/4" | 17" | 4-3/4" |
| 60" | SPS-60B | 58-7/8" | 16-1/4" | 4" min. | 59-3/4" | 17" | 4-3/4" |
| 74" | SPS-74B | 72-7/8" | 16-1/4" | 4" min. | 73-3/4" | 17" | 4-3/4" |
| 100" | SPS-100B | 98-7/8" | 16-1/4" | 4" min. | 99-3/4" | 17" | 4-3/4" |
Finished Opening vs. Overall Unit
The finished opening dimensions are the dimensions of the wall cavity after finish material is applied. The overall unit dimensions are larger — the unit overlaps the opening slightly. Frame to the finished opening dimensions, not the overall unit dimensions.
Installation Types
All installation types as documented by the manufacturer
The Spectrum Slimline supports three installation types. Each has distinct physical requirements. The recessed installation is the most common and requires a framed wall cavity. The wall-mount installation uses the supplied bracket and does not require any wall opening.
Recessed (Flush-Mount)
The unit is recessed into a framed, non-load-bearing wall cavity. The finished opening must match the dimensions in the table above. The 4" minimum depth is compatible with a standard 2x4 stud wall. Finish material — tile, hardwood, or drywall — can be run directly to the edge of the opening. A 5/8" trim frame is factory-applied to the unit perimeter.
The recessed installation requires hardwiring. A qualified electrician must remove the power cord and wire the appliance directly to household wiring using the supplied junction box. A dedicated 15A (or higher) breaker is required.
Wall-Mount (Surface Mount)
The unit mounts to a supplied wall bracket. No wall cavity is required. The bracket must be screwed into wall studs where possible. If studs cannot be used, the supplied plastic drywall anchors must be used. The bracket hooks must face upward and be level. Side skirt panels are installed after mounting. A dedicated 15A (or higher) circuit is required.
Mantel-Mount
The unit may be installed within a mantel surround. The minimum clearance of 11.8" (300mm) from the glass front to any structure above — including the mantel shelf — must be maintained. If paint or lacquer is applied to the mantel finish, it must be heat-resistant to prevent discolouration.
⚠️ Installation Restrictions
This unit is for indoor use only. Outdoor installation is expressly prohibited. The unit must never be placed on the floor or any surface — it must always be mounted to a bracket or framed into a wall before use. Do not use a wall-mount bracket from another manufacturer. Mobile home approval status is not specified in the installation documentation.
Electrical Requirements
All values from the Modern Flames installation manual
All four Spectrum Slimline models share identical electrical requirements. A dedicated circuit is mandatory — no other appliances may share the circuit.
- Plug-in: Plug directly into a dedicated 110–120V, 15A grounded wall outlet. Never use an extension cord or power strip.
- Hard-wire: A qualified electrician must perform hard-wire installation. Must comply with local codes, or CSA C22.1 (Canada) / ANSI/NFPA 70 NEC (United States). A dedicated 15A (or higher) breaker is still required.
- Heater settings: H0 (off), H1 (low — 733W), H2 (high — 1,465W). The flame operates independently from the heater.
Flame-Only Mode
The flame effect operates independently of the heater. The heater can only be activated when the flame is on. Running flame only draws significantly less power than 1,465W — however, the LED-only wattage is not specified in the installation documentation.
Clearance Requirements
All values from the Modern Flames installation manual — measurements taken from the glass front
All clearance values are measured from the glass front of the fireplace, as stated in the installation documentation.
Combustible Materials — Location Selection
When selecting the installation location, the unit must be at least 36 inches (914mm) away from combustible materials such as curtain drapes, furniture, bedding, and paper. During operation, keep combustibles at least 3 feet (0.9m) from the front of the heater.
Mantel paint or lacquer: If paint or lacquer is applied to the mantel finish, it must be heat-resistant to prevent discolouration.
Size-by-Size Reference
All dimensions from the Modern Flames installation manual
50" Model
60" Model
74" Model
100" Model
Frequently Asked Questions
All answers sourced from the Modern Flames installation manual
What is the minimum wall depth required to recess the Spectrum Slimline?
The Spectrum Slimline requires a minimum finished opening depth of 4 inches (102mm). This is compatible with a standard 2x4 stud wall. The finished opening depth is measured from the face of the finished wall surface to the back of the framed cavity.
What are the finished opening dimensions for the 74-inch Spectrum Slimline?
The SPS-74B requires a finished opening of 72-7/8 inches wide by 16-1/4 inches high by 4 inches deep (minimum). The overall unit dimensions are 73-3/4 inches wide by 17 inches high by 4-3/4 inches deep.
How much clearance is required above the Spectrum Slimline to a mantel or ceiling?
A minimum clearance of 11.8 inches (300mm) is required from the glass front to any mantel or ceiling above. This clearance applies to both mantel and ceiling installations. Clearance to the bottom, sides, and rear is 0 inches.
Can the Spectrum Slimline be installed beneath a television?
Yes, the Spectrum Slimline is designed to support installation beneath a TV. The required clearance above the glass front is 11.8 inches (300mm) to any structure above, including a TV mount or mantel shelf. No TV-specific clearance beyond this value is stated in the installation documentation.
What electrical circuit does the Spectrum Slimline require?
The Spectrum Slimline requires a dedicated 15 Amp (or higher) breaker on a 120V 60Hz circuit. It must be plugged directly into a grounded wall outlet — never into an extension cord or power strip. Hard-wiring is also supported and must be performed by a qualified electrician in accordance with local codes.