Dimplex Vital Spark Built-In Electric Firebox

The Dimplex Vital Spark Built-In Electric Firebox comes in five sizes — 26" (SPK26), 28" (SPK28), 33" (SPK33), 36" (SPK36) and 42" (SPK42). Unlike the linear fireplaces in the Dimplex range, this is a traditional fireplace shape — taller than it is wide in the larger sizes, with a moulded log set and a glowing ember bed rather than a ribbon of flame.

It is the firebox to specify when you are replacing a wood or gas fireplace and want the result to still read as a fireplace: same proportions, same log pile, none of the flue. Thirteen flame colours, three speeds, three brightness levels and five ember-bed colours, plus optional crackling fire sound, and all of it controllable from the Glen Dimplex Connect app.

Check Your Wall Depth First

Every size in this range needs a framed opening 9" deep. The firebox itself is under 8" — the rest is circulation space for the heated air, and it is not optional.

In practice that means a 2x8 wall is not enough. A 2x8 gives 7 1/4" of actual depth. You need a 2x10 (9 1/4" actual), a furred-out wall, or a masonry opening of that depth. If you are fitting into an existing masonry fireplace, measure the depth before anything else.

Will It Fit? Rough Opening by Size

Two things worth reading twice.

• The model number is not the opening. A "26-inch" Vital Spark needs a 24" hole; a "42-inch" needs 40 3/4". The firebox face is wider than the opening in every size, and that overlap is what covers the cut edge. Frame to the opening figure, never to the model name.
• The 26" is much shorter than the rest. At 17 3/8" of framing height it is barely half the height of the 42", and it is shorter than the 28" by more than five inches. The 26" and 28" are quite different shapes despite their neighbouring names — if you are choosing between them, compare the heights, not the widths.

Dimplex does not publish a viewing area for the Vital Spark series in any of their current documents, so we have not put one on this page rather than estimate it.

Key Features

• 13 Flame Colours
  Three flame speeds and three brightness settings on top, so the fire can be as traditional or as contemporary as the room needs.
• Moulded Log Set and Glowing Ember Bed
  Five ember-bed colours beneath a detailed log pile.
• Crackling Fire Sound
  Optional audio to go with the flame, at your chosen volume.
• Plug Kit Included
  Hardwire it, or use the 120 V plug kit that comes in the box — no extra accessory to buy.
• Flame Without Heat, and Heat Without Flame
  Both modes run independently, and the heater can be disabled entirely at installation.
• Louver-less Fan-Forced Heat
  1,500 W with a built-in thermostat, no visible vents to break the look.
• Smart Controls
  Glen Dimplex Connect app, multi-function remote, and hidden on-appliance controls.
• Smart Self-Diagnostics
  Built-in diagnostics that make troubleshooting straightforward.

Electrical Requirements

At 12.5 A against a 15 A breaker this wants a dedicated circuit even when you use the plug kit. And note that the heater is the same 1,500 W in all five sizes — a 42" Vital Spark gives you a bigger fire, not a warmer room.

Location and Clearances

This is an indoor appliance. The owner's guide states "Do not use this firebox outdoors."

Dimplex does not print ceiling, floor or combustible clearance figures for this series, nor a maximum mounting height, and we are not going to invent them. If you are planning a mantel close above the opening or a TV over it, call us and we will get a position confirmed with Dimplex before you build.

Specifications

About that warranty. Twelve months is the shortest term Dimplex offers — most of their range is two years and the Ignite lines run to five. We would rather say so here than have you find out later.

Documents & Downloads

• Owner's Manual (7217280100R00, English and French) — all five models, and the source for every framing dimension above
• Technical Specifications (R00, April 2026) — SPK28
• Technical Specifications (3P-086-R00) — SPK33
• Technical Specifications (3P-087-R00) — SPK36
• Technical Specifications (3P-088-R00) — SPK42
• Vital Spark Sell Sheet (R01, February 2026) — all five models
• Dimplex 2026 Electric Fireplace Collection

Dimplex has not published a standalone technical specification sheet for the SPK26 — its framing dimensions above come from the owner's manual, which covers all five models. If your architect needs the single-page spec for the 26", call us and we will request it from Dimplex.

Warranty

1 YEAR LIMITED WARRANTY on electrical components, running 12 months from the date of first purchase. Download the Dimplex warranty document. Note that Dimplex excludes Hawaii, Alaska, Yukon, Nunavut and the Northwest Territories from warranty coverage.