GB1

Frequently Asked Questions

Can the discharge from a food waste grinder be run through Great Basin® indoor units?

We do not recommend using these units in connection to a food waste grinder due to their small solids containment capacity. We recommend using one of the Great Basin® indoor/outdoor units that have solids containment capacity of 20% or more of the unit's liquid volume.

Can the Great Basin® indoor models be buried flush with the floor without using a riser?

These units can be buried flush with the floor without a riser, but it is recommended that they be located out of the traffic path. If the unit is placed in the traffic path, the GB2 and GB3 must have the gusset support kit (SGK2 / SGK3) installed inside the unit.

Can the Great Basin® units be used with a dishwasher?

These units can be used with a dishwasher. If the dishwasher will have a discharge temperature higher than 150 degrees Fahrenheit, the system will require a drain tempering valve to reduce the water temperature.

Can there be an air gap for an above grade unit on the outlet side?

If you are required to have an air gap, it is highly recommended that the air gap be preceding the unit due to smell mitigation from the contents and waste water coming from inside the unit.

Do the Great Basin® units require a fixture vent?

These units do not require a fixture vent. The internal design of the unit will ensure proper function without a fixture vent. Any venting to the piping connected to our unit is at the discretion of the local authority.

Do you have a heavy-duty steel cover for Great Basin® indoor units?

We do not have a heavy-duty cover option for our indoor units. If your installation requires a higher-load rated cover, you will need to install a GB-50 or larger.

How much space is needed between units when they are installed in series?

There should be a minimum of 6" between the units when installed in series. In a buried application, this space will ensure there is enough backfill in between the units.

Our fixture has an air gap and discharges into a floor sink, which is overflowing. How can we fix this?

Due to the low head pressure in this scenario, the first solution is to remove the internal flow control. This low head pressure ensures the unit will not exceed its certified flow rate. If that doesn’t solve the issue, the next solution is to add a flow restrictor to the tailpiece of the fixture.

What are the minimum and maximum riser heights of a buried Great Basin® indoor unit?

The minimum riser height is 2 1/8" (built in) and the maximum heigh for field cut risers is 25," which is equivalent to two FCR1 risers (sold separately).

What if we have a cover sealing issue with a unit installed on the floor or flush with floor without a riser?

Even though the cover is circular, there is a proper orientation to ensure the cover is completely seated. The Schier logo should run parallel to the long side of the unit.