A different sanitation architecture from a cassette toilet
The Dometic 310 is a gravity-flush RV toilet. Waste drops through the floor flange into a holding tank below the toilet, so the toilet and black-water tank work as one sanitation system.
This is fundamentally different from a cassette toilet, where the waste tank is removed through an exterior door. When a camper lists a Dometic 310, servicing therefore includes the black tank, its valves and the external dump connection as well as the toilet itself.
Porcelain bowl and foot pedal
Dometic specifies a vitreous ceramic bowl with a polypropylene seat. Flushing is controlled by a foot pedal and uses the camper's pressurised water supply.
The toilet does not need a separate flush-water reservoir. If water is unavailable because the fresh-water pump is off or the city-water supply is isolated, normal flushing is affected even though the waste tank may have capacity remaining.
Why water flow matters
The manual recommends 3–5 US gal/min water supply and states 2.0 gal/min as the minimum. Static supply pressure is specified at 30–100 psi.
MHS explanation.These are inlet requirements, not instructions to set every camper pump to 100 psi. The complete water system—including regulator, pump, tubing and other fixtures—must remain within its own limits.
Direct connection to the black tank
The 310 is intended for installation directly above a holding tank, using a 3-inch floor flange. That short gravity path is part of the design.
A remodel that moves the toilet without considering the discharge path is therefore not simply a furniture change. Floor structure, flange position and tank arrangement need to remain compatible.
Size and seat height
For the standard-height Model 310, Dometic publishes 20 in height, 15 in width and 19 in depth, with an 18 in / 457 mm seat height. The lid-up height is about 33 in / 838 mm.
These measurements help with bathroom planning, but service access, pedal movement and door clearance need to be checked in the actual camper.
What “porcelain toilet” does not tell you
A porcelain bowl describes material and feel, not the whole waste system. It does not indicate black-tank capacity, dump-valve location, tank heating or winter protection.
Those are camper-level characteristics. A technical card for the toilet should not invent them from the toilet model.
Water use and black-tank autonomy
The black tank fills with toilet waste and flush water. More flush water can improve bowl rinsing but also consumes black-tank capacity faster.
MHS explanation.There is no universal “days per tank” number for a Dometic 310. Autonomy depends on the holding-tank size, number of users and flushing habits.
Winterizing
The water valve and supply line are part of the winterization process. An empty black tank does not prove that the toilet's fresh-water side is protected from freezing.
Follow the camper and Dometic procedures for draining or approved winterizing fluid. Do not apply compressed air or chemicals outside the specified method.
Maintenance and seals
A poor bowl seal, leaking water valve or pedal problem should be diagnosed using the model identification label and service information. Dometic places the model label on the toilet base below the water valve.
Use that identification for parts. Similar Dometic gravity toilets share a general appearance but use different dimensions and components.
What to check in a camper
Confirm the label says Model 310. Check the foot pedal, bowl seal, water connection and the way the black tank is emptied. If the camper is used in freezing weather, ask how the toilet supply line and black tank are protected.
During handover, a real flush test with water is more useful than merely seeing a clean bowl.
Key takeaway
Dometic 310 is a gravity toilet designed to work with the camper's pressurised fresh water and a black holding tank directly below. Its comfort and serviceability depend on the entire plumbing and waste system, not the toilet alone.
Sources
Model 310 toilet only. Black-tank volume, heating and dump hardware are camper-level properties and are not inferred here.