New or used?
This is a perennial problem to answer with these and other capital purchases.
New machines will come with a comprehensive guarantee or manufacturers warranty as well as your statutory protection but are going to be one of the most expensive pieces of kit you will install in your pub. The moment you install one of these machines you must reckon on it depreciating to less than 25% of its cost over the following five years.
Second hand or renovated or reconditioned machines will cost you significantly less than a brand new machine. The down-side to this is that their long-term viability is severely limited and that you will get next to no warranty or guarantee. You may be lucky and get a trouble free, working machine that lasts for several years or you may be unlucky and get a machine that continually breaks down and costs more to repair than it is worth.
If you can afford to either out-right buy, lease or rent a new machine then do so you will have far less problems and more remedies and you can expect a well maintained machine to last for five years or more.
The only time I would be tempted to buy a reconditioned unit would be if, say, during the last few months of a tenancy (or just prior to a sale of a freehold) a glass/dishwasher became beyond economic repair then buying a short-term replacement would make sense.
Location
You will need to have water and electricity supplies within one to two metres of where you are proposing to install the machine. If these supplies are not to hand then you may have to budget for these small works to be undertaken before your supplier can install the machine.
Choosing the Right Unit
Selecting the right dishwashing unit depends on the amount of glasses/dishes you need to wash in a given hour and what you are washing. Some units are specifically designed to only wash glassware or pots and pans, and if your commercial kitchen has the space (and you have this high volume need), it might be a good idea to split dishwashing tasks between two specialized units.
You also need to account for volume. Keep in mind that when you are calculating how many racks of dishes/glasses you produce per hour, you should use the number produced at times of peak demand and don’t forget about future growth and seasonal trends.
Make sure the dishwasher you buy can handle these peak dishload times. On the other hand, the larger the unit, the more energy and water it consumes, and if dishes are processed too quickly then racks tend to go through half empty, resulting in inefficient operation. Make sure you take the time to accurately calculate dishload and select the right sized glass/dishwasher.
Energy Efficiency
As electricity and water costs continue to rise, selecting an energy efficient glass/dishwashing machine has become more and more important to pubs and their commercial kitchens.
Most commercial glass/dishwashers employ automatic fill and idle pump shutoff features, as well as a built in booster heating unit to improve energy efficiency.
Energy Star, a government run agency, now rates commercial dishwashers for their energy efficiency. Energy Star rated units will operate more efficiently than non-rated ones, so look for the Energy Star label when you’re buying a commercial dishwasher.