Fire Mountain Sierra 4 Burner vs CosmoGrill Pro Deluxe 5 Burner
We compare the Fire Mountain Sierra 4 Burner and the CosmoGrill Pro Deluxe 5 Burner across every dimension that matters - our scores, the key specs, and how each performs on the things you will actually notice day to day.
At a glance
| Fire Mountain Sierra 4 Burner | CosmoGrill Pro Deluxe 5 Burner | |
|---|---|---|
| Our score | 9.4/10 | 8.9/10 |
| Best for | Regular garden barbecuing for family and guests | Regular garden barbecuing for family and guests |
| Not ideal for | Anyone short on storage space, or wanting charcoal flavour from a pure gas model | Anyone short on storage space, or wanting charcoal flavour from a pure gas model |
| Brand | Fire Mountain | CosmoGrill |
Style and Setting
Fire Mountain Sierra 4 Burner
With the key specifications in mind, this gas barbecue is designed to suit a family-size outdoor grilling setup, including space for a main cooking area of 60 x 42cm and side shelves for food prep. Its stainless steel build is intended to provide a clean, modern appearance in UK gardens, patios and outdoor kitchens. Four burners support different cooking approaches, while the overall layout depends on leaving adequate clearance around the unit. The grill grates are cast iron, which is typically associated with good heat contact for everyday grilling, but they do require careful cleaning to avoid a build-up that can affect performance. This is a gas barbecue (LPG/propane), and the side burner is a separate burner with a pan ring rather than additional grill space. Outdoor use only is essential: keep the barbecue away from anything flammable, use it in open air, and turn off the gas supply at the bottle after use. Grease build-up can lead to flare-ups, so regular cleaning is important. Covering and storing the unit over winter helps prevent rust.
CosmoGrill Pro Deluxe 5 Burner
Style and setting suit this gas barbecue because it is built for a built-in, outdoor kitchen setup rather than a freestanding patio cart. The steel warming rack and lid thermometer support a more structured cooking space, with heat monitoring and staging easier to manage during grilling. Four main burners plus a side burner fit planned meal prep, while the lid helps keep cooking conditions more consistent. For homeowners without a built-in run, the required placement can look out of place, since cabinetry or a dedicated grill housing is needed for integration.
Size and Seating
Fire Mountain Sierra 4 Burner
The Fire Mountain is designed for family-sized grilling, with a main cooking area that measures 60 x 42cm. In practical terms, that cooking footprint allows larger cuts to be arranged without immediate overcrowding, and it supports planning multiple items across the available space. The seating capacity is influenced more by the chosen cooking pattern than by the grill footprint alone, because diners may want different foods at the same time. It can serve several people, while very large gatherings may still require extra cooking rounds.
CosmoGrill Pro Deluxe 5 Burner
Size and seating matter most with the CosmoGrill because it is a built-in outdoor gas barbecue, designed to be installed into an existing grill housing rather than used as a standalone unit on a patio. The cooking area is set up for four main burners plus a separate side burner, enabling multiple dishes to be prepared at the same time. A steel warming rack provides additional holding space for longer serving periods. Because it is built-in, buyers must match their outdoor installation requirements to avoid gaps and awkward access around the housing. For group cooking, seating capacity is driven more by the available table space than by the grill alone.
Materials and Build
Fire Mountain Sierra 4 Burner
The gas barbecue's Sierra 4 Burner uses stainless steel as the main body material, and it includes cast iron grates for the cooking surface, which can help with heat retention during grilling. The stainless steel frame is designed for routine outdoor weathering. Cast iron grates typically provide solid searing and more even hot spots, but they may also be heavier and require careful cleaning to prevent residue build-up.
CosmoGrill Pro Deluxe 5 Burner
Materials and build are what determine how well the gas barbecue handles day-to-day outdoor use, especially since it is described as a built-in outdoor gas barbecue rather than a free-standing model. The warming rack is made from steel, which is intended to cope with routine heat exposure. A lid is fitted with a temperature gauge, adding an element of feedback for safer cooking habits. For built-in installations, the surrounding frame and ventilation are important. The grill has four burners plus a side burner, which increases cooking options, but sturdy assembly during installation is still essential. Grease build-up can cause flare-ups, so routine cleaning is necessary, and covering or storing the grill over winter helps to reduce the risk of rust.
Comfort and Features
Fire Mountain Sierra 4 Burner
Comfort and Features focuses on the day-to-day grilling tasks the Sierra 4 Burner is set up for in a family-sized layout. The cooking area measures 60 x 42cm, which allows multiple portions to be cooked at once without feeling cramped. Four gas burners provide flexible control for different heat levels, and cast iron grill grates offer a stable cooking surface suitable for regular use. Side shelves add practical workspace for prepping food and keeping items close to the grilling zone.
CosmoGrill Pro Deluxe 5 Burner
Comfort and Features cover the day-to-day ease of using the CosmoGrill once it is installed. This unit is a built-in gas BBQ, designed with four main burners plus a side burner, allowing multiple pots or pans to be used at the same time. Heat monitoring is assisted by a lid thermometer. A steel warming rack provides additional space for keeping cooked items warm. In everyday use, operation is straightforward: ignite the gas, set the burners, cook the food, then use the warming rack as needed.
Who Is This For?
Fire Mountain Sierra 4 Burner
This BBQ suits people who want a family-sized outdoor grilling setup, with a 60 x 42cm cooking area and four main gas burners for everyday meals. It is aimed at households that regularly cook outside, and it benefits from side shelves that provide additional prep space. The stainless steel body is designed for solid day-to-day use. It is less suitable for small balconies because its overall size is not described as compact.
CosmoGrill Pro Deluxe 5 Burner
This built-in gas BBQ suits people who want to cook multiple foods at once, with four main burners plus a side burner (4+1) for tasks such as grilling and warming or using a separate pan. It is suited to households that host regular home garden parties, since the multiple cooking zones allow different items to be prepared in parallel. It also fits buyers who prefer a built-in outdoor setup rather than a freestanding trolley-style grill. It may be less suitable for small patios or for households without suitable access to a gas supply.
Fire Mountain Sierra 4 Burner: pros
- 4-burner
- Cast iron grates
- Instant heat and quick cleanup versus charcoal
Cons
- Gas bottle, regulator and hose are usually sold separately
- Needs covering or storing over winter to prevent rust
- Check the assembled size suits your space
CosmoGrill Pro Deluxe 5 Burner: pros
- 4 burners + 1 side burner
- Built-in
- Warming rack, lid thermometer
- Instant heat and quick cleanup versus charcoal
Cons
- Gas bottle, regulator and hose are usually sold separately
- Needs covering or storing over winter to prevent rust
- Check the assembled size suits your space
Our verdict
Our pick is the Fire Mountain Sierra 4 Burner (our score 9.4/10) - A practical gas barbecue (4-burner) for outdoor cooking. The CosmoGrill Pro Deluxe 5 Burner is still worth it if it is cheaper when you check, or if it better matches your specific needs.