Frequently Asked Questions


Do you stock coolers or are they custom made?

While we do maintain a number of different units in stock, we typically size each GRIDCOOLER Keel Cooler to specifications required by your engine, vessel, and operating conditions. We will certainly take a customer’s request for a stock cooler model into consideration when determining the appropriate cooler model.

Does recessing a cooler affect the size of a cooler?

Shallow recesses, like the ones we describe in our Installation and Maintenance Manual, will have little to no effect on the size of a cooler. The key parameter to proper design and placement of a recess is ensuring that the heated seawater can easily escape the recess box.

How do I know what size cooler is needed for my application?

In order to recommend the best cooling solution for your application, our sales and engineering team will need to know specific information about your engine, vessel, and operating conditions. The recommendation form lists the specifications we will need. Once the form is completely filled out, our team will be able to determine the size of cooler necessary for your application.

If you do not have all the engine information required on the recommendation form, we will help you. Fernstrum maintains current files on all major marine engine manufacturers.

What is a Compression Sealing Kit?

A compression sealing kit is used when a GRIDCOOLER Keel Cooler is mounted utilizing a cofferdam (top hat) installation. The kit consists of additional washers that are unfinished on one side and soft gaskets. This kit is an added measure to help prevent the pressurized coolant within the cofferdam from potentially seeping around the through-hull pipe fitting.

Download the Compression Sealing Kit Installation Information
GRIDCOOLER Keel Cooler Installation and Maintenance Manual

What is included in a Gasket Set?

A gasket set includes all of the gaskets normally supplied with a new cooler. This includes gaskets that are mounted internally as well as externally on the hull. If isolators are standard equipment on your cooler, they will also be provided in the gasket set.

What is included in an Anode Set?

Included in an anode set are two anodes, four mounting bolts, and four washers. (In most cases, one anode set is required per GRIDCOOLER Keel Cooler.)

What is the maximum internal pressure to test a GRIDCOOLER Keel Cooler?

Do not exceed 35 PSI (2.41 Bar) when pressure testing a GRIDCOOLER Keel Cooler.

Where do I find the Model Number and/or Serial Number?

The Model Number and/or Serial Number are stamped into both ends and/or on the top of the header.