HPC Fire Forno Dual Fuel Pizza Oven Size Guide

The HPC Fire Forno comes from the Forno de Pizza product family (acquired by HPC Fire Inspired in 2020). Within that family, the Forno EI Series is the portable cart-mounted configuration covered by this guide. It includes the glass-tiled refractory oven, the stainless steel hearth, the stainless steel vent, and a powder coat black steel cart. Total assembled weight is approximately 450 lbs. The oven, hearth, and cart can be disassembled and transported using the HPC transporting kit; reassembly is a two-person job.

Refractory specifications per the owner's manual: the oven is shaped as a single one-piece refractory (not multi-piece mortar assembly), with a two-inch wall thickness that reflects heat back into the oven and keeps the outside temperature roughly one-third of the interior temperature. The refractory material withstands temperatures up to 2,400°F.

• Dedicated outdoor kitchens with a flat, level cooking footprint to position the cart and surrounding seating. The Forno cart sits on its own steel base and rolls into the cooking zone.
• Outdoor entertaining patios where pizza nights, smoked roasts, and bread baking are part of the dining experience.
• Properties with proper gas service (either a stubbed natural gas line for the -NG model or a propane tank location for the -LP model). Professional gas hookup is required.
• Covered patios that maintain 36 inches of clearance above the oven opening to any combustible roof, soffit, or overhang.
• Households that want both convenience and authenticity: gas for quick start-ups and consistent heat, wood for true wood-fired flavor on top of the gas flame.

• Indoor installation. The Forno is for outdoor use only. The owner's manual prohibits use in any enclosed space (vehicle, garage, screened porch, tent, building) due to carbon monoxide hazard.
• Recreational vehicles or boats. The manual specifically prohibits RV or boat installation.
• Tight under-counter or built-in cabinetry without proper ventilation. The Forno EI Series is the cart-mounted unit, not the built-in series. For built-in outdoor kitchen counter installation, consider the Villa Series (35 inch deep counter) or Di Napoli Series (DIY enclosure) from HPC Fire instead.
• Commercial or food service applications on the standard warranty (the warranty covers residential use only).
• Operation in any wind condition without proper site selection. Maintain the manufacturer's clearances and place on a level stable surface.
• Burning anything other than oak wood in the wood mode. Per the manual, oak only, 1 year dried, debarked, 1-1/2 to 3 inch diameter, 12 to 14 inch length. No painted wood, sap, oils, varnishes, or accelerants.

• Best in calm weather. Pizza ovens perform best with stable airflow; high winds disturb flame and combustion air.
• Outdoor temperature. The 30-minute preheat to pizza temperature is based on typical outdoor conditions; cooler ambient temperatures extend the preheat time.
• Rain and snow. An optional FDP-COVER-FORNO vinyl cover is available to protect the oven when not in use. The cover should be installed only after the oven has fully cooled (allow 45+ minutes after burn).
• Wet refractory. If the refractory has absorbed moisture (long storage, rain exposure), follow the manual's first-firing curing procedure: gradually step up from 1/2 inch flame to 2-1/2 inch flame over 5 hours before normal use. Heating wet refractory too quickly can cause cracking.

• Connection location: right side of the oven, on the underside of the oven hearth plate.
• Shut-off valve: required between the house and the oven.
• Supply pressure: minimum 3.5 inches W.C., maximum 7.0 inches W.C.
• Gas line sizing per manual:
• 4 ft at the oven (stainless flex line): 1/2 inch diameter.
• Up to 25 ft total run: 3/4 inch diameter.
• 26 to 50 ft total run: 1 inch diameter.
• 51 to 100 ft total run: first 2/3 in 1-1/4 inch, final 1/3 in 3/4 inch.
• Leak test: required prior to first use, annually thereafter, and any time the gas system is altered.

• Supply pressure: minimum 8.0 inches W.C., maximum 11.0 inches W.C.
• Regulator: ships with the unit; QCC1 type fitting; 11 inches water column at the appliance.
• Tank size: 20-lb or 30-lb propane cylinder (not supplied).
• Max fill: never fill beyond 80 percent of cylinder capacity.
• Tank enclosure ventilation (if cylinder is housed inside a cabinet enclosure): top ventilation openings within 5 in of the top of the enclosure, 180 degrees apart, 1 sq in per lb of stored fuel; floor-level openings 1/2 sq in per lb. Minimum 2 inch clearance between enclosure floor and ground.
• Cylinder storage: never store a spare LP cylinder under or near the appliance, and never store cylinders indoors.

• Voltage: the electronic ignition system runs on 3 Volts DC, supplied by either two D-cell batteries or a 110V to 3V transformer adapter.
• Outlet location (if using the adapter): 110V 15-amp GFCI outlet on the left side of the oven base, 12 to 18 inches from the oven hearth.
• Battery life: 6 months to 1 year. Check periodically; extreme heat and cold reduce battery life.
• Do not ground to a gas pipe. Keep the power cord and fuel hose away from hot surfaces.

• Required. HPC Fire Inspired recommends installation by professionals locally licensed by the authority having jurisdiction in gas piping.
• National codes: National Fuel Gas Code ANSI Z223.1/NFPA 54 (US) or CSA B149.1/B149.2 (Canada); National Electrical Code ANSI/NFPA 70 (US) or CSA22.1 (Canada).
• Annual service: NFI Gas Specialist (US) or WETT-certified pro (Canada).
• Warranty consideration: all instructions must be strictly followed to qualify for warranty. Never alter the product or configuration.

The HPC Forno is sold as an -NG model that comes set up for natural gas. The electronic ignition lights the pilot, then the burner. Turn the gas control knob from OFF slowly through the pilot position to ON to regulate burner flame height. Gas alone will preheat the oven and bring the hearth to pizza-baking temperature in roughly 30 minutes. Use natural gas as the sole fuel for quick weeknight pizza, simpler bread baking, and easy operation when you do not want to manage a wood fire.

The HPC Forno is also sold as an -LP model set up for liquid propane. The supplied regulator and QCC1 connection attach to a 20-lb or 30-lb propane cylinder. Pilot ignition and operation are otherwise identical to the natural gas model. The same gas control knob and electronic ignition apply. Choose LP if your outdoor kitchen does not have a stubbed natural gas line and you do not want to install one.

Both the -NG and -LP versions also burn dry oak wood. The procedure per the manual: light the gas, place small pieces of dried hardwood on the burner, regulate the gas flame so the wood ignites, then add more wood once smaller coals have formed. Keep the gas line ON while burning wood; the gas flame keeps the oven hot and the wood flame steady, and burns off smoke as the fire dies. To smoke food after cooking, turn the gas completely off at the control knob and at the LP tank/shut-off valve, remove the door vent, close the door, and let smoking wood chips smolder. Never run gas with the door installed unless the oven vent is in place; otherwise the oven can build pressure and explode.

• Pizza: hearth target 625 to 650°F. Brush the center of the hearth, place pizza with the aluminum peel, turn ¼ turn every 30 seconds, watch for golden cheese and crust.
• Bread: front of the oven at 300 to 400°F. Turn on gas, leave door half-open, regulate heat, bake.
• Roasts and meats: door in place (with oven vent), do not exceed 600°F. The door acts as a damper, controlling oxygen.
• Grilled foods: steaks, chickens, brats, vegetables on the optional FDP-GRILL RACK (cast iron, 14×14×4 in).
• Smoking: gas off, door vent removed, door closed, smoking wood chips on coals at lower temperatures. The door's temperature gauge gives a reading on smoking temp.
• Pan-cooked: cast iron skillet on top of the grill rack for sears, sautés, and one-pan dinners.