Unicook Heavy Duty Adjustable Porcelain Steel Grill Heat Plate Shield Replacement, Heat Tent, Flavorizer Bar, Burner Cover, Flame Tamer for Gas Grill, Extends from 11.75" up to 21" L, 3 Pack

A simple swap that can save a tired gas grill

Opening my grill at the start of the season, I found the usual culprit behind uneven heat and flare-ups: the flavorizer bars had rotted through. Rather than hunt for expensive OEM parts, I tried the Unicook adjustable heat plates. They’re straightforward porcelain-coated steel shields that telescope from 11.75 inches to 21 inches long (3.75 inches wide, 1 inch tall). In practice, they turned a limping grill into a dependable weeknight cooker again—with a few quirks worth noting.

Build quality and what’s in the box

Each plate is a two-piece, telescoping assembly made from 1.2 mm porcelain-coated steel. The coating is even and smooth—typical black porcelain enamel—but not overly thick. Unicook includes stainless steel M5 bolts and wing nuts, which matter: regular hardware rusts quickly in a grill environment. The plates are rigid and don’t flex easily, which helps them sit flat and resist warping.

This is a three-pack, so it’s a direct drop-in for many three-burner grills. If you’ve got four burners, you’ll need two sets. There’s also a stainless steel version if you prefer to avoid porcelain-coated steel altogether.

Fit and installation

The headline feature is the adjustable length. I measured my original bars, set the telescoping pieces to match, and snugged the wing nuts. The adjustment range is generous, but pay attention to orientation: installed one way, the plates extend all the way to 21 inches; flipped, the usable length tops out around 18.37 inches. That’s not obvious from a glance, so check before you tighten everything down.

Width and height are fixed at 3.75 inches wide and 1 inch tall. On my mid-size three-burner grill, the width dropped right into the support rails and covered the burners end to end. If your grill uses very wide or triangular heat tents, or relies on tabs to lock the shields into slots, these might not “click” in the way OEM parts do. Mine sat properly on the rails but didn’t have dedicated tab holes. If you want a more positive lock, two quick workarounds:

• Use high-temperature, stainless self-tapping screws to pin the plates to the existing rails.
• Add a small stainless washer under the rail lip to capture the edge of the plate.

Both are optional; I ran them unsecured and had no rattle at cooking temps. The included wing nuts make length adjustment easy and tool-free. For front-to-back burner layouts, the plates run front-to-back; for side-to-side burners, rotate them 90 degrees. The telescoping design accommodates both.

Installation time, including measuring and setting lengths, took under 20 minutes for three plates.

Performance on the grill

I tested them with three quick cooks: a “bread test” for evenness, burgers (to stress flare-up control), and chicken thighs (to see how they handle fatty drippings over a longer cook).

• Heat distribution: With the old rusted shields, I had two hot stripes and a cold zone. With the Unicook plates, the bread test browned far more uniformly. The overlap area of the telescoping sections didn’t create a noticeable cold spot, likely because the plate sits a full inch above the burner and radiates across the span.

• Flare-up control: Smash burgers are my flare-up litmus test. The plates kept direct flame off the drippings, and while I still saw small, manageable licks of flame (expected on any gas grill), the raging bursts that used to char edges simply didn’t happen. Chicken thighs cooked skin-side down without burning while the renders smoked off the plates.

• Preheat and searing: Preheat times remained on par with my original parts, hitting 500°F in a reasonable window. The surfaces got hot enough to produce good Maillard browning and crosshatch marks with cast-iron grates. If your original shields had lots of perforations, these solid plates may feel slightly “softer” on initial heat-up, but the difference is minimal and offset by the flare-up protection.

The plates act as both a shield and a radiant surface. That balance keeps burners protected while promoting even heat. I also liked that I didn’t notice any off-gassing or coating smell during the initial burn-in; I still ran the grill at high heat for five minutes before the first cook, as a best practice.

Durability and maintenance

At 1.2 mm thick, these are sturdier than many generic replacements. Porcelain-coated steel, however, is not a lifetime material. The enamel will chip if you hammer on it with a metal scraper, and any exposed steel will rust over time—especially if you live near the coast or leave the grill uncovered. That said, the thickness buys time.

My maintenance routine:

• After cooking, run the burners on high for a few minutes to carbonize drippings.
• Once cool, brush the plates with a nylon or brass grill brush. Avoid sharp metal scrapers on the coating.
• A light wipe with an oily rag before storage helps repel moisture.
• Keep the grill covered and dry; moisture is the enamel’s enemy.

If you want maximum corrosion resistance, Unicook’s stainless version is worth a look. It trades the enamel’s easy cleanup for better long-term rust resistance, especially in humid climates.

Compatibility notes and limitations

These plates are designed for “most” gas grills, and the adjustable length enables that claim. Still, there are caveats:

• Width and height are fixed. Confirm you have 3.75 inches of rail-to-rail space and at least 1 inch of vertical clearance above the burner and below the cooking grates.
• Some grills rely on tabbed shields that lock into slots. These plates don’t have tab cutouts. They’ll rest on rails, but they won’t lock without simple mods.
• Infrared burners, specialty sear zones, or non-standard shield shapes may not be compatible.
• The telescoping overlap reduces the number of vent perforations compared to certain OEM designs. I didn’t see issues with combustion air, but if your grill runs perpetually rich, make sure your burners and venturis are clean.

Measure first, and if you’re on the edge of the adjustment range, install with the correct orientation to hit the full 21-inch length.

Value and what you’re really buying

OEM replacement flavorizer bars can be surprisingly pricey, and some manufacturers don’t sell them for every model year. The Unicook adjustable heat plates sidestep that problem with a fit-most approach and a reasonable price. Functionally, they protect burners, reduce flare-ups, and smooth out heat—exactly what you need to breathe life into a grill body and burners that are otherwise fine.

A small bonus: because these are smooth, cleanup is quick, and they shed grease better than the thin, rusty steel they replaced. They’re not magic shields—you still need to mind flare-ups—but they make the grill more predictable.

Tips for best results

• Measure the original plates and the space they occupy. Confirm length, width (3.75 inches), and height (1 inch) clearances.
• Assemble to length and test fit before fully tightening the wing nuts.
• Ensure the orientation that allows up to 21-inch extension; otherwise, you may top out around 18.37 inches.
• Don’t overtighten the bolts to the point where thermal expansion can’t move; snug is enough.
• Season lightly with cooking oil after install to help the coating shed moisture.
• Cover the grill and empty the grease tray regularly to keep moisture and corrosion at bay.

Bottom line

The Unicook adjustable heat plates did exactly what I needed: they revived a grill that had become unpredictable, they tamed flare-ups, and they spread heat more evenly across the grate. Installation was quick, the hardware is sensible, and the adjustability makes them adaptable to a range of mid-size gas grills.

They’re not perfect. On some models, the lack of tab holes means they sit rather than lock in; porcelain-coated steel will eventually corrode if abused or left wet; and you must be mindful of the orientation to reach the full 21-inch extension. But those are manageable quirks, not dealbreakers.

Recommendation: I recommend these for anyone looking to extend the life of a gas grill with rusted flavorizer bars without chasing down overpriced or unavailable OEM parts. If you live in a harsh, humid climate or want the longest possible lifespan, consider the stainless version; otherwise, the porcelain-coated plates strike a practical balance of performance, ease of install, and value.