The use and abuse of Combi-ovens

The combi-oven combines electrical circuitry with water and heat - three things that logic says should be kept well apart.

Manufacturers know what a punishing work schedule combi-ovens have, so the build quality across all the big brands ranges from good to very good. Potentially there is a lot that can go wrong on a combi-oven, but in practice they are reliable, providing they are regularly and properly serviced and staff don't abuse or neglect them.

Ask any service engineer how often a problem on a combi-oven bears all the hallmarks of misuse and neglect and the answer is likely to be "more regularly than it should do". So what are the ways to keep the combi-oven running sweetly and the maintenance bills down?

The biggest self-inflicted problem is chefs not knowing how to correctly operate or look after it. This is combi-oven enemy number one.

If every head chef took the time to make sure the kitchen team learnt what a combi-oven could and could not do, that would cut maintenance bills overnight. Head chefs will spend time teaching a commis how to hold a knife to turn vegetables, but too often any training on the combi-oven is just a dashed conversation: push that button, push this one and wait for the bells to ring. We are talking about the most versatile prime cooking equipment a kitchen will ever own - and possibly the most expensive.

So what should chefs do to keep down maintenance costs? Check door seals every day and really clean them. Chefs give equipment manufacturers and service engineers no end of grief about "rubbish" door gaskets, but chefs can contribute to premature gasket blow-out. It's not just about cleaning the door seal with a quick wipe, but proper cleaning inside the gasket fold, removing the gunge that accumulates behind it.

Replace the seals as soon as they get torn. A damaged or cracked seal can allow moisture into the electrical controls compartment and cause major damage to the circuitry. When chefs complain about the cost of having to replace computer circuit boards through heat or damp damage, it isn't always the fault of the manufacturer. Faulty door seals will also let heat and steam out and raise running costs.

Clean the oven properly at the end of the shift to stop dirt accumulating. Some combi-ovens have an overnight self-clean facility, but if it's a manual-clean model, then don't leave it until the next day when sticky food has hardened. And wipe down the outside of the combi-oven, too.

Here are two service engineer secrets: first, clean combi-ovens need less servicing than dirty ones; second, engineers prefer to service clean machines. Engineers will do grunge cleaning, but does the kitchen budget stretch to paying for a service engineer to chisel away congealed fat?