Dometic MasterFlush 7600 Series Toilet Control Module Kit

The control module is the brain of your Dometic MasterFlush 7600 macerating toilet. It's the small electronic unit that reads the flush switch, times the fill, runs the macerator pump, and shuts everything down cleanly when the cycle's done. When it fails, the whole head goes with it. You press flush and get nothing. Or the red light flashes and the pump won't spin. This kit, Dometic part 385312089, is the genuine replacement module for the 7600 series, and swapping it out is one of the more satisfying repairs on a boat, because it takes a dead toilet and brings it right back to life.

Here's the thing about macerating heads. They're electric, so there's a logic board somewhere making the decisions. On the 7600 that's this module. It handles the timing between the rinse water and the macerator motor so you get a clean flush without flooding the bowl or leaving waste behind. Over the years, moisture and vibration take their toll. Boats are hard on electronics. A module that's spent five or six seasons in a damp head compartment eventually gives up, and the symptoms are pretty consistent. A flashing red indicator. A flush button that does nothing. A pump that hums but won't complete the cycle.

If that's what you're seeing, and the black tank isn't full and the breaker's good, the control module is the first thing we'd check. It's a far cheaper fix than replacing the entire toilet, and you keep the bowl, base, and plumbing you already have installed.

This part fits the Dometic 7600 series, which includes the popular 7640 model you'll find factory-installed on a lot of newer boats and coaches. Before you order, match your toilet's model number to the 7600 family. Dometic's sanitation line has several series that look similar from the outside but use different control electronics, so the model badge matters. If your head is a 7600 or a 7640, this is your module.

Install is straightforward for anyone comfortable with 12-volt work. Kill power at the breaker first, always. The module connects through keyed plugs, so you're not guessing which wire goes where. Unplug the old one, mount the new module in the same spot, reconnect, and restore power. Give it a test cycle before you button up the access panel. Most folks have it done in under an hour, and you don't need any specialty tools beyond a screwdriver.

A couple of real-world notes from boaters who've been through this. Keep the module dry. If your head compartment sweats or you've had a slow leak somewhere, sort that out while you've got the panel open, because chronic moisture is what kills these in the first place. And go easy on what goes down the bowl. Marine-safe toilet paper and nothing else. The macerator and its control electronics last a lot longer when they're not fighting wipes and paper towels. A little dielectric grease on the plug connections helps too, and it only takes a minute while you've got everything apart.

This is a genuine Dometic kit, not a knockoff board, so it speaks the same language as the rest of your 7600's wiring and sensors. That matters on a system where the toilet, the tank sensor, and the flush logic all have to agree. A mismatched substitute can throw false tank readings or odd cycle behavior. The factory module just works.

Bottom line. If you've got a Dometic MasterFlush 7600 or 7640 that's gone dark, flashing a red light, or refusing to flush, and you've ruled out a full tank and a tripped breaker, this control module is the repair. It's the genuine part, it's a bolt-in swap, and it'll have the head back in service the same afternoon.