This manual must be read and understood before installation, adjustment, service or maintenance is
performed. Modication of this product can result in property damage.
Superior Durability: Dometic® holding tank systems (HTS) are molded from linear low density polyethylene (LLDP) resin.
Polyethylene is best-suited for holding tank construction because of its resistance to corrosion and odor permeation, and it will last
longer than the life of a typical berglass hull.
Leak-Proof Design: All hose connections in Dometic holding tanks are on the top of the tank, eliminating possibility of leakage
due to a faulty connection below the liquid level of the tank contents. Our unique diptube design reduces the risk of plugging while
keeping the residual contents in the tank to a minimum.
Typical
Discharge Outlet
amount of residual efuent
ISO/USCG Compliant: Dometic HTS models are fully compliant with the ISO 8099:2000(E) standard and applicable requirements of
the United States Coast Guard for pleasure craft installation.
Odor-Free Design: Dometic tanks have extra-heavy wall thickness to prevent odor permeation. Holding tank systems can be tted
with a SaniGard™ in-line vent lter that stops unpleasant odors from escaping through the holding tank vent.
Implosion Protection: Dometic holding tanks are equipped with a TankSaver vacuum relief valve which prevents damage from
dockside pumps that operate at very high levels of vacuum. The TankSaver valve opens automatically under vacuum conditions, but
remains sealed regardless of shock-loading or vibration.
Multiple Tank Outlets: Most HTS models are equipped with two discharge outlets. One is for connection to a deck-mounted
discharge tting and one is for connection to an overboard discharge pump.
HTS Components: Every HTS is built with high-quality Dometic sanitation system components. See page 6 for details.
Diptube
Discharge Outlet
amount of residual efuent
HTS with Vacuum Generator, Discharge PumpHTS with Basic Fittings
VENT FITTING
SEACOCK
DECK
DISCHARGE
TANK
MONITOR
HOLDING TANKSEACOCK
DISCHARGE
PUMP
VENT FILTER
HOLDING TANK
TANK
MONITOR
Dometic Corporation reser ves the right to change specifications without notice.
DECK
DISCHARGE
VENT FILTER
DISCHARGE
PUMP
2
VENT FITTING
Installation
CHOOSING A LOCATION FOR THE HTS
As a general rule, the HTS should be positioned as low in the hull as possible with all interconnecting hoses or pipes sloped to permit
gravity drainage and prevent potential hose odor permeation.
The holding tank must not be exposed to temperatures above 120°F (45°C). Do not place near heat sources such as engine
manifolds, water heaters, generators, etc.
Be certain to estimate holding tank weight when lled (typical efuent weighs about 9 lbs. per 1 gallon or 1.08 Kg per liter). Make
certain to allow for total lled weight when selecting materials for mounting the tank. Also consider impact of full tank on vessel trim.
Preparing a Mounting Surface
1. Mount tank to surface that supports the entire area of the
tank.
2. If required, fabricate mounting surface and toe blocks from
13 mm or 19 mm (1/2-inch or 3/4-inch) plywood.
3. Do not mount tank on projections such as screw or bolt
heads, which could puncture the tank.
4. Do not allow holding tank to block free ow of bilge water.
AVOIDING HOSE ODOR PERMEATION
• Hose failure due to odor permeation almost always
occurs in hose runs which retain sewage when the
system is not in use.
• Eliminate all unnecessary runs which retain trapped
liquids, if possible.
• Where possible, use rigid PVC pipe in sections that
cannot be arranged to drain.
• Simplify hose layout by removing unnecessary valves.
[For specic installations, some regulations and
standards may require the installation of a vented loop
(anti-siphon valve), one-way valve or seacock in
sewage discharge piping.]
Integrated mounting feet
in holding tank simplify
installation.
Mounting surface can be
made from plywood and
securing straps.
Complicated plumbing layout
HTS / VACUUM GENERATOR CONNECTIONS
Vent line
Outlet to
through-hull
discharge
fitting
Discharge
pump
Vent filter
Vacuum
generator
Tan k S ave r
vacuum relief
valve
Tan k
level indicators
Outlet to
dockside
discharge
fitting
Inlet from
toilet
Simplified plumbing layout
BASIC HTS CONNECTIONS
Inspection port
Outlet to
through-hull
discharge
pump
Tan k S ave r
vacuum relief valve
3
Outlet to deck
discharge fitting
Inlet from toilet or
vacuum generator
Vent line
Installation (cont’d)
PLUMBING CONNECTIONS AND HOSE LAYOUTS
When connecting exible hose to plastic ttings, use Dometic
Hose Lubricant or silicone grease on end of tting and inside
hose end to make connection easier.
Do not use any other lubricants, sealants or adhesives when
connecting sanitation hoses and plastic ttings.
Do not restrict the ability to pull the hose or pipe.
HOSE LUBRICANT
YES
TABS
AVOID
AVOID
YES
TROUGH SUPPORT
EXCELLENT
YES
Avoid binding corners and sharp bends.
Do not use wire ties to secure the hose or pipe.
Support exible hose every 12 inches
(.3 m), and support rigid pipe every 5 feet
(1.5 m).
When creating new holes, avoid
reinforcement stringers and tabs.
STRINGER
IF HTS-BASIC TANK FITTINGS ARE NOT ASSEMBLED TO TANK, FOLLOW THESE STEPS.
3-inch cap – inspection port
1. Place cap into 3-inch (76 mm) threaded hole (g. 1 ) and tighten until hand-tight.
2. Using spanner wrench or large channel locks, tighten cap until very little or no black seal is visible above inlet port (g. 2 ).
3. To remove cap for tank inspection, use spanner wrench or large channel locks.
1
2
Inlet and discharge elbow fittings
1. Apply threaded plastic pipe sealant around threads of elbow (g. 3 ).
2. Tighten elbow into desired tting on tank (g. 4 ).
3. To properly position elbow to receive sanitation hose, turn elbow only
in clockwise direction (g.
opposite direction may loosen connection and cause leakage.)
4. Make sure to connect waste discharge hose(s) to tting(s) marked as
“Was te O nly.”
5. When connecting sanitation hose to plastic elbows, use silicone
grease on end of tting and inside hose end to help make connection
easier and leakproof. Be sure to use two hose clamps to secure each
connection.
). (Turning the elbow in
4
4
3
4
Installation (cont’d)
CLAMP CONNECTIONS FOR FLEXIBLE HOSE AND
SOLVENT BONDING FOR RIGID PIPE AND FITTINGS
FITTINGS
Dometic recommends that each hose connection be
secured with two hose clamps to prevent any leaks.
Position clamp screws 180° apart from
each other and tighten clamps.
1
Vent Line and Filter Installation
• Holding tank vent lines must be free of low points which can trap liquid and prevent
the free ow of gases from or air into the holding tanks.
• Do not use non-reinforced hose for vent lines. Over time, it will tend to kink and
effectively block the vent.
• A holding tank vent lter will absorb heavier-than-air gases associated with sewage
and eliminate a source of malodor from the exterior of the boat. See vent lter
details in this manual (page 6).
When installing vent lters that are not mounted directly on an HTS unit:
• Avoid areas near excessive heat sources such as engine manifolds or lights.
• Do not install the lter below top of holding tank.
• The lter can be mounted in any position. Installations near the through-hull vent
reduce the chance of lter damage from overlling of the holding tank.
1. Use PVC cleaner on both
bonding surfaces.
2. Use PVC cement (must
contain tetrahydrofuran) on
both bonding surfaces.
3. Connect parts using a twist
and hold motion until the
cement is set.
4. Let the joint cure for at least
four hours or according to
Because Dometic holding tanks may require minimal service in normal operation, the tank must be installed so that there is easy
access to the tank inspection port, discharge pump and vent lter (if installed).
An in-line maintenance valve must be installed in any piping runs which retain liquid and are connected to components that may
require periodic servicing (such as discharge pumps).
Cleaning
A small amount of water remains in all marine holding tanks. It is good practice to rinse the tank after the contents have been
discharged. This can be accomplished by adding water to the toilet bowl. Add 8 ounces (237 ml) of Dometic® Holding Tank
Deodorant to the bowl. Flush the entire contents into the holding tank and continue ushing until the discharge from the holding
tank is clear.
Do not use chlorine-based cleaners, caustic cleaners or chemicals, such as drain-opening products, as they may damage the
system’s seals and hose.
Winterizing
If using the HTS with VacuFlush® components, refer to VacuFlush toilet owner’s manual for winterization instructions.
If using antifreeze to winterize the HTS, use only propylene glycol freshwater antifreeze that does not contain alcohol. Antifreeze that
contains alcohol will result in damage to your sanitation system.
1. Pump out holding tank.
2. Thoroughly ush the system with fresh water before adding propylene glycol freshwater antifreeze to the HTS.
5
HTS Components
DTM04 Level Monitor and Micro-Float Switches*
I ncludes four tank
levels – Empty, Low, Mid
and Full. Micro-float
switches are installed in
holding tank. No electrical components contact
waste or water. Operates
on 12 or 24-volt DC. Uses
only .008 amps at 12 V
DC. Micro-oat switches
are installed either as a
unit (with a 3-inch cap)
or as separate indicators.
VacuFlush
Shutdown Relay*
To prevent overfilling a
holding tank, a shutdown
relay is supplied with HTSVG models. When the
tank reaches "Full", the
relay shuts off the vacuum generator, preventing
further flushing of the
toilet.
Combined
Float Switches
Separate
Float Switches
TankSaver™ Vacuum Relief Valve
Prevents damage due to tank implosion from
dockside pumps that generate very high vacuum.
TankSaver valve opens automatically under
vacuum, but remains sealed regardless of shockloading or vibrations.
Holding Tank Vent Filter*
With odor-removing lter media, the vent lter stops odors from
escaping the holding tank vent. Keeps boats smelling clean
and pleasant. Each
cartridge is good for
an entire season and is
easily replaced.
TW Discharge Pump*
Runs dry without harm. Draws
6 amps at 12 VDC. Delivers ow
rate of 3.9 gallons per minute (14.7
liters per minute). Connects to
through-hull tting. Check Marine
Sanitation Regulations for information on areas where discharge is
allowed.
* Not available on all HTS models.
VacuFlush® Vacuum Generators*
On HTS-VG models, VacuFlush vacuum generators combine
the vacuum tank and vacuum pump in one unit. All models
eliminate hose runs between the vacuum tank and pump of
previous VacuFlush systems. HTS vacuum generators feature
high-performance vacuum pumps, offering quieter operation
and faster vacuum generation than previous models.
Other HTS Features
OdorSafe® Plus Sanitation Hose
OdorSafe Plus hose provides the best odor barrier of any marine
hose available. It delivers
up to 19 times greater
resistance to sulfurous
malodors than other “noodor” marine hoses. On
HTS models, it's used
for all 1.5-inch (38mm)
hose connections. It's
also best for connecting
the discharge pump to
the through-hull and deck
waste ttings.
Diptube Discharge
Our diptube discharge design allows for removal
of waste from the top of the holding tank rather
than near the bottom of the tank. This feature
greatly reduces the opportunities for stagnant
sewage to sit in tank discharge lines – a main
cause of odor permeation and hose failure.
Plumbing, Electrical Specifications
Plumbing Connection Dimensions
Inlet Fitting Size: 1-1/2 inch 38.1 mm
Outlet Fitting Size: 1-1/2 inch 38.1 mm
Vent Inlet/Outlet Size: 5/8 inch 15.9 mm
307341143 90º Bend 90º Ell for connecting 1½" (38mm) PVC pipe sections.
307341425 Threaded Male Adapter Adapts 1½" (38mm) PVC pipe to 1½" (38mm) NPT thread.
307347286 45º Wye Makes three way connection to 1½" (38mm) PVC pipe.
307341812 Double Bend Makes three way connection of 1½" (38mm) PVC pipe.
307341158 Sanitary Tee Makes three way connection of 1½" (38mm) PVC pipe.
307342971 Special Adapter for Toilet Outlet Adapts VacuFlush toilet outlet to other PVC pipe
connections.
307341104 PVC 45° Street Ell For custom tting design. Adapts to all 1½" (38mm) PVC ttings shown
here.
307341161 PVC 90° Street Ell For tight bends. Can be used with other PVC ttings shown.
1½" (38mm) Hub.
307346087
307230310307230311
307230312307230313
307238802307238798
307341113
307348684
307341085
307341425
307341812
307342971
307341513
307238803
307341143
307347286
307341158
Plumbing Pipe and Hose
PART NO. DESCRIPTION
307001540 PVC Rigid Pipe 1½" (38mm) ID x 5-ft. (1.5m) length.
307342871 OdorSafe® Plus Sanitation Hose 1½" (38mm) ID x 50-ft. (15.2m) roll.
307345650 Vent Hose 5/8" (16mm) ID x 50-ft. (15.2m) roll. Use for holding tank vent line.
Connects to SaniGard vent lter.
7
307341104
307341161
307001540
307342871
Customer Service
There is a strong, worldwide network to assist in servicing and maintaining your toilet system. For the Authorized Service Center near you,
please call from 8:00 a.m. to 5:00 p.m. (ET) Monday through Friday.
You may also contact or have your local dealer contact the Parts Distributor nearest you for quick response to your replacement parts
needs. They carry a complete inventor y for the Dometic product line.
Telephone: 1 800-321-9886 U.S.A. and Canada
330-439-5550 International
Fax: 330-496-3097 U.S.A. and Canada
330-439-5567 International
Web site: Dometic.com
Warranty and Product Liability
North America and Rest of the World: Manufacturer’s One-Year Limited Warranty
Dometic Corporation, Sanitation Division warrants to the original purchaser only that this product, if used for personal, family or household
purposes, is free from defects in material and workmanship for a period of one year from the date of purchase.
If this Dometic product is placed in commercial or business use, it will be warranted to the original purchaser only to be free of defects in
material and workmanship for a period of ninety (90) days from the date of purchase.
Dometic reserves the right to replace or repair any part of this product that proves, upon inspection by Dometic, to be defective in material
or workmanship. All labor and transportation costs or charges incidental to warranty service are to be borne by the purchaser-user.
EXCLUSIONS
IN NO EVENT SHALL DOMETIC BE LIABLE FOR INCIDENTAL OR CONSEQUENTIAL DAMAGES, FOR DAMAGES RESULTING FROM
IMPROPER INSTALLATION, OR FOR DAMAGES CAUSED BY NEGLECT, ABUSE, ALTERATION OR USE OF UNAUTHORIZED
COMPONENTS. ALL IMPLIED WARRANTIES, INCLUDING ANY IMPLIED WARRANTY OF MERCHANTABILITY OR FITNESS FOR ANY
PARTICULAR PURPOSE, ARE LIMITED TO A PERIOD OF ONE YEAR FROM DATE OF PURCHASE.
IMPLIED WARRANTIES
No person is authorized to change, add to, or create any warranty or obligation other than that set forth herein. Implied warranties, including those of merchantability and tness for a particular purpose, are limited to one (1) year from the date of purchase for products used for
personal, family or household purposes, and ninety (90) days from the date of purchase for products placed in commercial or business use.
OTHER RIGHTS
Some states do not allow limitations on the duration of an implied warranty and some states do not allow exclusions or limitations
regarding incidental or consequential damages; so, the above limitations may not apply to you. This warranty gives you specic legal
rights, and you may have other rights which vary from state to state.
To obtain warranty service, rst contact your local dealer from whom you purchased this product or go to http://www.dometic.com/enus/
Americas/USA/Customer-Support / for a dealer near you.
Europe: Warranty and Customer Service
Warranty arrangements are in accordance with EC Directive 44/1999/CE and the normal conditions applicable for the country concerned.
For warranty or other service, please contact our Dometic Customer Service department. Any damage due to improper use is not covered
by the warranty.
The warranty does not cover any modications to the product or the use of non-original Dometic parts; the warranty does not apply if the
installation and operating instructions are not adhered to and no liability shall be entertained.
Product Liability
Product liability of Dometic Group and its subsidiary companies does not include damages which may arise from: faulty operation; improper
alterations or intervention in the equipment; adverse effects from the environment which may impact the equipment itself or the direct vicinity
of the equipment or persons in the area.
To obtain warranty service, rst contact your local dealer from whom you purchased this product or go to www.dometic.com to locate a
dealer near you.