One cast plate over two burners
The Weber SLATE GP 56 cm Premium Plancha (item number 1500232) is a griddle for liquefied gas. Under one continuous plate of porcelain-enamelled cast iron sit two stainless steel burners, with a hood above; there is no grate. Weber lists it among the portable Slate planchas and names picnics, the garden and setting it up on a table as places to use it. According to the manufacturer, burgers, pan dishes, seafood and vegetables belong on the plate.
In our price box it is listed at Amazon at approx. €460 (Amazon page on 20 October 2026: €459.99). In its own online shop Weber asks €599.00 (checked 21 October 2026).
Within the Slate range, the 56 is the middle size. Below it is the GP 43 cm (item number 1500231), above it two 76 cm units: the GPD with a trolley and the GPSB. In our gas grill overview it is listed among the gas grills, even though it has no grate.
Construction, dimensions and ignition
According to Weber, the cooking chamber measures 56.00 x 41.50 cm at a height of 5.60 cm, and Weber gives 2,270 cm² as the total cooking area. The rated output with propane is 4.7 kW. Each burner has its own control knob with the settings OFF, START/HIGH, MEDIUM and LOW. Ignition is by spark from an ignition electrode, triggered by a red ignition button, one burner at a time. In the product photo, both knobs sit in a narrow extension to the right of the plate, which is also where the gas hose leaves the unit.
Closed, the plancha needs a footprint of 81.50 x 57.50 cm and is 25.00 cm high. With the hood open it grows to 72.50 cm in height and 64.00 cm in depth; the table has to leave this space to the rear and above. Weber states a weight of 24 kg. Four adjustable feet compensate for uneven surfaces. They are adjusted by turning, but according to the manual not during use and not while the unit is hot.
The hood is not a cooking chamber. In the manual it is called a protective cover hood, it is intended solely to protect the griddle during storage, and the plancha must not be operated with the hood closed. It must be open when you light it. Fat and food residue run through an opening in the cooking surface into a removable grease tray, in which a disposable drip tray sits.
The following details are missing from the product page and from the twelve-page manual: the output of each individual burner, the thickness of the cast plate, a temperature display or thermometer, a heat-up time to a particular temperature, the number of people the surface is intended for, the material of the frame and hood in detail (the manual only says the exterior is made “where applicable” of stainless steel, porcelain enamel and plastic), a matching stand for the 56, the country of production, and how long spare parts are available. The side table is contradictory: the specification lists “side tables 1”, while the description mentions the option of adding a folding grill table.
In detail: two zones without a lid
A plancha cooks by contact. The food lies on a closed metal surface, flames and fat do not meet, and the heat comes from below. Cast iron has a useful property here: as a general rule, a solid cast plate stores a lot of heat and releases it more evenly than thin sheet metal, but it takes longer to heat up. Weber gives 10 to 15 minutes of preheating on the highest setting, depending on air temperature and wind.
Weber advertises two promises that sit side by side: even heat across the whole surface and “dual zone heat” for cooking at two temperatures at the same time. Both work through the two separately adjustable burners. If both knobs are set the same, the plate should be similarly hot everywhere; if you set one burner to LOW, a cooler half results, on which vegetables keep cooking while burgers fry next to it.
One detail from the manual suggests that the two halves are not equally strong. For Germany the nozzles are drilled differently: burner 1 has 0.77 mm, burner 2 has 0.60 mm. At the same gas pressure the larger bore lets more gas through, so the half over burner 1 is likely to be the hotter one even at the same setting. The documents do not say which side that is. This is our inference from the nozzle sizes; nobody has measured it.
If you convert the total output to the area, the 56 comes to roughly 2.1 watts per square centimetre (4.7 kW over 2,270 cm²). According to Weber, the smaller GP 43 cm reaches almost exactly the same value with 3.7 kW over 1,754 cm². Only the GPD 76 cm has more output per area, with 10.6 kW over 3,483 cm², which is a good 3 watts per square centimetre, almost half as much again. So the 56 is not a stronger 43, but a larger one.
On maximum temperature the sources differ slightly: Weber and the Amazon feature text say “over 260 °C”, while the Amazon title says “up to 260 °C”.
Does the Slate GP 56 replace a normal gas grill?
No. There is no grate, and the hood must not be closed during use. Cooking with the lid closed, for a roast or whole chicken legs, for example, is therefore ruled out. The Slate complements a grill, or replaces it for people who would fry almost everything in a pan anyway.
What works in a large frying pan works well here; what needs a closed cooking chamber does not. For melted cheese on the burger, Weber sells a melting dome as an accessory. Fuels other than liquefied gas are ruled out. The manual explicitly prohibits charcoal, briquettes and lava stones, as well as connection to mains gas and any conversion to natural gas; according to Weber, conversion is not safe and voids the warranty.
If you are looking for a classic gas grill at the same price, you end up at the Weber Spirit II E-310, which according to the Amazon catalogue has three burners, a porcelain-enamelled cast iron grate and wheels.
These three alternatives are worth a look
| Model | The difference | Price | Our rating | Choose this one if |
|---|---|---|---|---|
| Weber Slate GP 56 cm Premium Plancha (this one) | 2 burners, 4.7 kW, 2,270 cm², 24 kg | approx. €459.99 | 8.4 | you want to cook for a larger group on one surface at a stone table in the garden |
| Weber Slate GP Portable Premium Gas Griddle | the 43 cm Slate (model 1500231): 3.7 kW, 1,754 cm², 19.5 kg | approx. €319 | 8.4 | you carry the plancha often and can do with a good 500 cm² less surface |
| Cozze G-500 Plancha | according to the Amazon catalogue 5.0 kW, built-in thermometer, regulator and 1.01 m hose included | approx. €359 | 8.1 | you want a temperature display on the unit |
| Weber Spirit II E-310 | 3 burners, cast iron grate, wheels, cooking with the lid | approx. €459.99 | 9.2 | you have a fixed spot and want steaks on a grate |
The prices are guide values from our price boxes and change. The rating is our editorial assessment based on the available data; we did not measure anything on any of the four devices.
When the Slate GP 56, when something else
The first question is surface area. 2,270 cm² is a good 500 cm² more than the 43, almost 30 per cent. In return, the 56 weighs 4.5 kg more. If you regularly carry the plancha to picnics and mostly cook for two or three people, in our assessment you will manage with the smaller Slate, which according to the price box costs approx. €319, against approx. €460 for the 56. If you keep it permanently on a table in the garden, take the larger one.
Second, the table. Weber promotes setting it up on a table, but the manual prohibits any glass surface and any combustible surface as a base and requires a level, stable surface. As we read it, that rules out wooden and glass tables, while a table made of stone or metal fits. Clearances also apply: combustible materials must stay at least 61 cm from the back and side panels, and nothing combustible may be within a 60 cm radius; the manual gives (treated) wood on a patio or porch as an example. Flammable liquids must be 7.50 metres away.
Third, the balcony. Weber says nothing at all about balconies. According to the manual, use is only permitted outdoors in a well-ventilated area, and explicitly not in garages, buildings, covered walkways, tents, enclosed areas and under combustible structures. A balcony with a wooden ceiling above it is therefore ruled out for us; whether gas is allowed at all is governed by house rules and the tenancy agreement. More on this in the guide Grilling on a balcony.
Fourth, the budget. According to the price box, the Cozze G-500 costs approx. €359, the Slate approx. €460, and according to the catalogue the Cozze comes with a regulator and hose. For the Slate you need to add a gas bottle and, if you leave it outdoors, a hood. We would mainly choose the Slate GP 56 if the cast plate and Weber’s separate warranty periods are worth it to you.
Gas bottle, accessories and running costs
According to Weber, no gas bottle is included. The manual allows bottles with a fill of at least 3 kg and at most 13 kg and wants them behind the grill on the right-hand side so that nothing tips over. According to the manual, the grill is fitted with a pressure regulator that may differ from the one shown depending on the country. Whether the regulator and hose are in the German box is stated neither on the product page nor in the manual.
Before connecting, all burner knobs are set to OFF and the bottle valve or regulator lever is closed. The manual describes four connection types (turning clockwise, turning anticlockwise, lever engaging, collar). Tighten by hand only; too much force damages the regulator coupling and valve. Before each new gas container, you check the seals; with damaged or worn seals the unit stays off. Changing takes place in a well-ventilated place, preferably outdoors and away from ignition sources.
On consumption, the manual gives 330 g per hour with propane. By calculation, a 5 kg bottle therefore lasts a good 15 hours at full rated load, and an 11 kg bottle around 33 hours. If you cook on LOW, you get further; how far cannot be derived from the data. Which bottle size suits you is covered in the guide Gas bottle for the grill.
In its own shop, Weber lists three accessories for the Slate GP 56: the Premium cover hood for plancha at €59.99, the plancha accessory set at €74.99 and the melting dome at €49.99. Disposable drip trays for the grease tray are a recurring cost. Spare parts are available through your local dealer or through weber.com.
Cleaning, care and safety according to the manual
After each use you switch off, let the plate cool for 5 minutes and push excess fat, oil and food residue with a scraper or spatula into the hole leading to the grease tray. The griddle is washed by hand with mild washing-up liquid, then rinsed thoroughly and dried. The manual is clear here: “The griddle is NOT dishwasher-safe. Do not immerse the griddle in water.” You may only remove it once the grill is switched off and has cooled completely. For stubborn residue, Weber recommends a paste of three parts baking powder to one part water, left to work and then wiped off without scouring, with vinegar if needed.
You clean the grease management system before you move the grill or cook, which is meant to prevent grease fires. You do not line the grease tray and cooking chamber with aluminium foil. The burners are cleaned on the outside with a stainless steel grill brush, the insect screens on the air openings with a soft bristle brush. You never use a brush that has already been used to clean grill grates for this, and pointed objects do not belong in the burner openings. According to the manual, a clean burner shows flames with a yellow tip that turn through light blue into dark blue; weak yellow flames and a smell of gas indicate blocked screens. On the outside, warm soapy water is enough for painted, enamelled and plastic surfaces, and stainless steel is wiped with a non-abrasive cleaner and a microfibre cloth. Acid rain, swimming pool chemicals and salt water can cause rust, so in such surroundings you clean more often.
Before first use, a leak check is mandatory, even if the dealer assembled the unit, and afterwards after every disconnection and reconnection. You mix 20% liquid soap with 80% water and apply the solution at three points: between bottle and regulator, between regulator and regulator hose, between regulator hose and valve. Open flames are prohibited while you do this. If bubbles form, there is a leak and the grill stays off; if there is a leak at the regulator or valve, you must never tighten the regulator, but contact customer service. Because the soap solution is slightly corrosive, you rinse the connections with water afterwards.
If you smell gas, the manual prescribes four steps: cut off the gas supply to the appliance, extinguish all open flames, open the lid, and if the smell persists, move away from the appliance and call your gas supplier or the fire brigade immediately. In the event of a grease fire, you switch off all burners immediately and keep the lid closed until the fire has gone out. You never extinguish an oil or grease fire with water; what helps otherwise is covered in the guide Preventing grease fires. During use, the plancha is never left unattended and is not moved. For handling, Weber requires heat-resistant grill gloves with contact heat resistance of level 2 or higher according to DIN EN 407 (a standard that applies in the EU).
The warranty is staggered by component. Cooking chamber and lid: five years against rust-through or burn-through, the paintwork two years, with fading and discolouration excluded. Stainless steel burner tubes: five years against rust-through or burn-through. The griddle made of porcelain-enamelled cast iron: five years, excluding rusting. All other parts: two years, excluding normal wear. It applies only to the original purchaser; according to Weber, online registration is advantageous but not required, and you keep the proof of purchase. Your statutory warranty rights remain unaffected.
Who is it for?
For households with a stone or metal table in the garden who like to cook for several people on one surface and either already have a grill with a grate or will not miss one.
For campers there is a clear limit: the manual rules out installation in or on caravans and boats and prohibits use in a vehicle, in a boot and on a load bed, whether car, lorry, estate, minivan, SUV, caravan or boat. On a non-combustible table outdoors, by contrast, it is not ruled out. If you want to use the plancha commercially, rent it out in a holiday flat or share it in a multi-occupancy building, you should also read the warranty terms: according to the manual, it applies only to use by individual private households, not to commercial use, rental properties or multi-occupancy buildings. If you are still undecided between designs, the Grill Finder is a quicker way to the right type of grill.
