Quick Answer: Installing an electric fireplace insert is a 5-step process: cap the chimney to keep water out, close and seal the damper (no longer needed once you’re not burning anything), get a power outlet into the firebox opening, slide in and level the insert (securing any brackets your model includes), then attach the trim or frame to cover the gaps. Most of this is DIY-friendly — Angi’s 2026 cost data puts electric insert labor at around $225, the lowest of any fireplace-insert type, because the only step that typically needs a licensed electrician is running a new outlet if one isn’t already there. Dimplex’s own insert manual sets the electrical baseline: a 15-amp, 120-volt circuit, dedicated if the breaker trips regularly.
Converting an old wood or gas firebox to electric is far simpler than either alternative it replaces — no flue liner, no gas line, no combustion inspection. The tradeoff most first-timers get wrong isn’t the mechanical part, it’s forgetting the chimney is still open above an insert that produces no draft to keep water and cold air out. Here’s the process in order, plus what to size and check before you buy.
Before you start: measure and check clearances
Grab the exact width, height, and depth of your existing opening, front and back, since masonry fireboxes often taper, per our sizing guide. Then check the numbers in your insert’s own manual or listing. Requirements are model-specific, so here is what two common inserts actually publish:
| Requirement | Dimplex DF3033ST firebox (owner's manual) | PuraFlame Western 33" EF45D (puraflame.com) |
|---|---|---|
| Unit size | 31 1/2" W x 22 3/8" H x 9 1/8" D | 35" W x 27" H x 8.78" D overall; firebox body 32.3" W x 25.6" H x 7.8" D |
| Minimum opening | 30 3/4" W x 22 5/8" H x 9 3/8" D (enclosure if not using a Dimplex mantel) | Opening must fit the 32.3" x 25.6" body; the 1.5" trim edge on top and sides covers the gap |
| Power | 15A/120V circuit; dedicated preferred, required if the breaker trips regularly; can also be hardwired | 120V plug-in only; "CANNOT be hard wired" |
| Extension cord | Avoid; if unavoidable, No. 16 AWG minimum, rated 1,875W or more | Not addressed in the listing |
| Base | Two rubber feet for air circulation; never directly on carpet | Flat bottom, sits directly on the firebox floor |
| Combustibles | At least 3 ft from the front of the unit (furniture, curtains, bedding) | Not addressed in the listing |
| Warranty | See Dimplex warranty card | 1 year |
Two things stand out. First, the “minimum opening” figure matters more than the product’s nominal size: a “30-inch” Dimplex needs a 30 3/4” opening, and a “33-inch” PuraFlame is really a 32.3”-wide body. Second, the plug-in-only PuraFlame can’t be hardwired, so if you want the cord fully hidden, the outlet has to be inside or right next to the opening.
The 5-step installation process
- If it was a gas fireplace, deal with the gas line first. Shut off the supply and have the line disconnected and capped before the old gas logs come out. In most places this is a job for a licensed plumber or gas fitter; check your local code. Nothing else on this list should happen while a live gas line is still in the firebox.
- Cap the chimney. If your chimney doesn’t already have a rain cap, add a cover plate before installing the insert. Once the insert is in and the damper is sealed, there’s no airflow left to keep water from settling in the flue.
- Close and seal the damper. An electric insert makes no smoke or fumes, so the damper isn’t doing anything useful anymore — sealing it shut stops drafts and heat loss straight up the chimney, the same energy-waste path a working flue causes on a gas or wood fireplace.
- Get power into the opening. Every electric insert runs on a standard 120V household outlet. Dimplex’s DF3033ST manual requires a 15-amp, 120-volt circuit and warns that other appliances on the same circuit can trip the breaker, which is when a dedicated circuit becomes required. It also tells owners not to wire their own new outlets or circuits. If your firebox doesn’t already have an outlet, this is the one step worth hiring a licensed electrician for, and it keeps the cord out of sight. It’s the same 1,500W/12.5A math covered in our installation cost guide. Avoid extension cords; Dimplex allows one only as a last resort, and only at No. 16 AWG or heavier and rated for at least 1,875W.
- Slide in, center, and level the insert. Set the firebox into the opening and check how your model is meant to sit. The Dimplex DF3033ST rests on two rubber feet that leave an air gap underneath, and its manual says never to set it directly on carpet. The PuraFlame Western has a flat bottom that sits straight on the firebox floor. Level it, and secure any brackets your model includes so it doesn’t shift in daily use.
- Attach the trim or frame. Check what’s actually in the box first. Some inserts ship with a full trim kit; others, like the base PuraFlame Western 33”, only have a 1.5” trim edge and need the separate trim-kit version for a wider gap. This is also the point to test heat and flame before final assembly — plug it in and confirm both work while everything’s still accessible.
PuraFlame Western 33" Electric Fireplace Insert
- $389.99 direct from puraflame.com for the base 33" (EF45D), which has a 1.5" trim edge on the top and sides; the full trim-kit version (EF45D-TR) is $461.99, measures 44.1" W x 31.5" H, and ships in two packages that may arrive on different days.
- Also sold in 23", 26", and 30" sizes ($269.99, $329.99, and $349.99 for the base units on puraflame.com), so measure the opening before picking the width.
- 750W/1,500W heater with an adjustable thermostat, rated by PuraFlame as supplemental heat for up to 400 sq ft. Plug-in only; PuraFlame says it cannot be hardwired. 1-year warranty.
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What’s DIY vs. what needs a professional
Steps 1, 2, 4, and 5 — capping the chimney, sealing the damper, positioning the insert, and attaching trim — are standard DIY work with basic tools (screwdriver, level, caulk or foam sealant for the damper). Step 3, the power outlet, is the one place most guides recommend a licensed electrician, specifically when there’s no existing outlet inside the opening or the circuit needs upgrading. If your opening already has a working outlet within reach, you can skip the electrician entirely and plug straight in, which is why Angi’s $225 average labor figure for electric inserts runs so far below gas or wood-burning insert installs — there’s simply less professional work involved.
The bottom line
Installing an electric fireplace insert is a same-day project for most homeowners: cap the chimney, seal the damper, confirm you have power in the opening, level and secure the insert, then trim it out. The only step that regularly needs a professional is adding a new outlet — everything else is well within reach with basic tools. For picking the right insert before you start, see our best electric fireplace insert roundup, and if the unit stops heating after install, our troubleshooting guide covers the most common causes. Installing a wall-mount or recessed built-in instead of an insert? Our general installation guide covers those steps separately.
Last updated October 29, 2026: replaced the generic clearance table with requirements published in the Dimplex DF3033ST owner’s manual and on puraflame.com, added the gas-line step for gas fireplace conversions, and corrected the PuraFlame Western card. The $389.99 base unit does not include the full trim kit; that’s the separate $461.99 EF45D-TR listing.