Not every commercial dishwasher or glasswasher removes waste water in the same way.

Many businesses only discover the difference during installation, when the waste pipe sits too high or the site drainage layout does not suit the machine they have ordered.

Businesses comparing different types of commercial dishwashers and glasswashers often focus on basket size or wash performance, but drainage configuration can be just as important during installation.

In simple terms, gravity drain machines rely on waste water flowing naturally downhill into the drain point, while drain pump machines actively push waste water away from the appliance when natural drainage alone is not possible.

What Is A Gravity Drain Machine?

Gravity drain machines remove water naturally through the outlet.

For this to work correctly:

• the site drain point usually needs to sit lower than the machine outlet
• the pipework should continue downhill
• and the site must allow water to drain away naturally.

In simple terms, gravity drain machines rely on waste water flowing naturally downhill into the drain point, while drain pump machines actively push waste water away from the appliance when natural drainage alone is not possible.

What Is A Drain Pump Machine?

A drain pump machine includes an internal pump that pushes water away from the appliance.

This becomes useful when:

• the drain point sits above the machine outlet
• pipework needs to travel upwards
• the connection is further away
• or the site layout does not allow a natural fall.

Manufacturers offer many undercounter glasswashers and dishwashers in both gravity drain and drain pump configurations to suit different installation environments.

Where Pump-Assisted Drainage Is Commonly Needed

Pump-assisted drainage is often useful in:

• basement bars
• mobile catering units
• kiosks
• island bars
• older buildings
• and sites where pipe positioning limits natural drainage.

Smaller glasswashers are not automatically exempt. Even compact undercounter machines may still require a drain pump depending on the site layout.

One Of The Most Common Installation Mistakes

A lot of operators assume a replacement machine will automatically work with the existing drainage setup.

In reality, newer appliances may have different outlet heights or drainage layouts, even if the machine size appears similar.

This can lead to:

• installation delays
• additional plumbing work
• unexpected costs
• or engineers being unable to complete installation on the day.

What Should You Check Before Ordering?

Before ordering a commercial dishwasher or glasswasher, it is worth confirming:

• where the drain point is positioned
• whether the pipework runs uphill
• how far the water needs to travel
• and whether the machine requires gravity drainage or a drain pump configuration.

If you are unsure which setup your site requires, speak with your installer, plumber or equipment supplier before ordering.

At Anglia Catering Equipment, we help businesses choose commercial dishwashers and glasswashers with the correct drainage configuration for their site layout, installation requirements and operating environment.