Hose Installation
Different marine toilet manufacturers use different sizes
of outlets . Check outlet size of toilet(s) or size of toilet
discharge hose(s) that will connect to holding tank .
• If connecting previous toilet discharge hose to new
tank, use adapter fitting to connect to 38 mm tank
inlet fitting, if necessary .
• If installing new hose from toilet to tank, use 38 mm
ID Dometic OdorSafe Plus hose . Use adapter fitting
between toilet and hose, if necessary .
• Use 90° elbow fittings to make bends when radius is
less than 210 mm .
• A second inlet fitting is provided with the Dometic
holding tank if a separate inlet fitting is preferred and
only one outlet fitting is required .
• OdorSafe Plus hose or rigid pipe should be installed
on hose runs that may retain sewage .
• Some existing seacocks and through-hull discharge
fittings may be 25 mm in diameter . If so, use a 38
mm x 25 mm reducer and 25 mm MaxFlex
sanitation hose .
Note
A valve with a lockable handle must be on all
through-hull fittings that emit sewage .
Note
Maintenance valves must be installed in any
piping runs which retain liquid and are
connected to components which require
periodic servicing .
Caution – Flooding Hazard!
If the toilet, holding tank or any components are connected to any through-hull fittings,
properly installed seacocks must be installed in all piping connected to the through-hull
fittings . Seacocks must be easily accessible to all users of the system . All valves must be
full-bore valves and of marine (corrosion resistant) quality . Screw-to-close gate valves are
not recommended . Failure to do so can result in flooding, which can cause the loss of life
and property .
Caution – Flooding Hazard!
Some marine practices and/or standards require the installation of a properly positioned
ventilated (vented) loop in the discharge piping to prevent back-siphonage of seawater
into the holding tank . It is up to the system installer and boat owner to select appropriate
means of preventing backflow into the holding tank .
12
Dometic Holding Tanks
Marine Toilet to Holding Tank
(fig. 7 , page 5)
7
Item
Description
First marine toilet
1
(25, 38, or 40 mm discharge)
Second marine toilet
2
(25, 38, or 40 mm discharge)
Wye or Tee fitting (must be
3
installed in direction of flow)
Hose from toilets to holding
4
tank
5
Holding tank
Discharge Hoses (fig. 8 , page 5)
Item
Description
Discharge hose to deck fitting
1
(38 mm ID)
Discharge hose to seacock and
2
discharge fitting (38 mm ID)
3
Discharge pump
4
Holding tank
8