“Which combi oven should I buy?” is maybe the most common question the sales desk gets. Usually what people are really asking is one of two things: which brand, or gas versus electric. The first is mostly marketing. The second genuinely matters, and the honest answer has moved around a fair bit in the last few years.

Running cost: the moving target

For most of the 2010s, gas combis were clearly cheaper to run. Somewhere between 30% and 50% cheaper per hour, depending on your tariffs and how hard you ran the oven. Energy prices spiked in 2022 and electricity briefly hit gas-like levels. Then both settled, and right now gas is back in the lead — roughly 35% cheaper per service hour for a typical 10-grid model on current UK commercial tariffs.

That gap isn’t a law of physics. Electricity prices could shift again, gas could shift, and green levies could land on one side or the other. If you’re modelling running costs for a ten-year equipment purchase, assume the gap will narrow over time.

Installation: where gas gets expensive

Here’s the part nobody mentions in the brochure. A gas combi needs:

  • A Gas Safe-certified installation
  • An adequate flue run to outside, usually with a draft diverter
  • Gas interlock ventilation linking the oven to the extraction hood
  • A pressure-checked supply from the meter, not a repurposed cooker connection

Drop all of that into an existing compliant kitchen and the install is straightforward. Put it into a refit or a new-build, and you’re probably looking at £1,500–£4,000 of ancillary work on top of the oven. Electric combis, meanwhile, usually need nothing more than a 32A or 63A three-phase supply and a water connection.

For that reason alone, a surprising number of pub-kitchen refits end up going electric these days. The installation saving pays for one or two years of the running-cost difference, and the kitchen opens sooner.

Speed

This is the bit the brochures exaggerate. At the same grid count, a gas and an electric combi heat up at basically the same rate. Maybe 30 seconds in it. Cavity temperature recovery between loads is also broadly identical. Anyone telling you gas is dramatically faster is quoting marketing from a decade ago — modern electric combis have caught up.

Consistency and programming

This is where brand matters more than fuel type. All of the serious commercial combi makers — Rational, Unox, Convotherm, Blue Seal — produce consistent, repeatable cooking when properly calibrated. The big differences are in the software: how the programs are structured, how easy it is to add a cleaning cycle, whether you can store recipes per section, and how the oven tells you when something’s wrong.

If your kitchen runs a tight, repeatable menu with multiple chefs, spend the extra on the best programming you can afford. If you run a daily-changing menu driven by a head chef who just wants temperature, time and humidity controls, pick the cheapest reliable model. Extra programming features will go unused.

When each makes sense

  • Go gas if the kitchen is already gas-equipped, you’ve got a flue and interlock in place, and you’re running long shifts (five hours plus daily). Gas pays back fastest in high-use sites.
  • Go electric if the site has no existing gas provision, you’re in a mixed-use or listed building where adding a flue is hard, you run shorter services, or you’re chasing a lower upfront bill on a refit.
  • Get someone to look at the supply first, either way. A 10-grid electric combi wants 19–22 kW of three-phase. A 20-grid wants 35 kW or more. Plenty of kitchens discover too late that their incoming supply is undersized.

One final thought

Combi ovens are the single most versatile piece of kit in a commercial kitchen. Whatever you spend, you’ll get your money back: a good one cooks better, cleans faster, and holds temperature more honestly than most older rigs. If you’re weighing up gas versus electric and the numbers are close, let the site dictate. The kitchen that doesn’t need any extra building work usually wins.