Congratulations on the purchase of a Lavacmarine toilet. Lavac marine toilets are firmfavourites with sailors throughout the world,providing their owner with a long and trou-ble free working life.The Lavac is one of the most simple tooperate marine toilets available. After use,the seat and lid are closed and the pump isthen operated for 14-16 strokes (For fullinstructions see page 21). As waste ispumped out, the bowl is sealed causing avacuum which draws in the flushing water.It’s as simple as that!Within this handbook you will find informa-tion and practical help on installing, runningand maintaining your Lavac. If you requireany further help or advice, please contactus either by:
Over many years we have taken advice fromsailors around the world concerning theirrequirements for marine equipment and ourcurrent range is a result of this ongoing com-mitment. If you have any comments or help-ful hints that you would like to share with us,we would be very pleased to hear from you.
Installation kit provided with your lavac
All Lavac marine toilets are provided wit thefollowing parts for installation.
Pump – Hand (T/A: On Bulkhead; U/D:Behind Bulkhead) or Electric (12 volt DCor 24 volt DC, including wiring loom, timeswitch, fuse and fuse holder)Plastic Bleed Plugs (Spares No.TLZ9251)Self adhesive operating instructionsOwners Handbook.
Because the nature of an installation variesfrom owner to owner, certain componentsare easier to source locally. We thereforefeel it is best for you to purchase the follow-ing separately, depending on your require-ments.
4 x 6mm (¼“) diameter Stainless Steelsecuring bolts or screws for base4 x 6mm (¼“) diameter Stainless Steelsecuring bolts or screws for pumpReinforced sanitation grade hose –length dependant on installation:19mm (¾“) bore for inlet38mm (1½“)bore hose for outletHose clips
3
The Lavac SystemGeneralThe well known Lavac system is uniqueand probably the only single action, aboveor below water line, marine WC.
The Lavac has a china pan and is availableas either hand or electrically operated. Onthe electric models 12 or 24V DC can besupplied.
To flush simply close the lid and operate asingle pump. Pressure is reduced in thebowl as waste goes out and flushing wateris drawn in. A small air bleed valve in theinlet pipe prevents siphoning.
The particularly hygienic operation andquietness are characteristics which inthemselves make Lavac a popular choicefor discerning owners. Simplicity of opera-tion, robustness and reliability are furtherimportant features.
By using a diverter valve the Lavac’s pumpcan also be used for other pumping opera-tions, such as shower tray discharge, bilgepumping or discharge of the holding tank(see page 20).
Because legislation is now prohibiting over-board discharge from toilets, or at leastmaking it impractical, this edition of theLavac owners handbook now gives guid-ance on holding tanks (see pages 18).
FeaturesEasy and versatile in installation.Can be mounted under bunk or lockerand pulled out for use.Pump, separate from bowl, can bemounted in most convenient position(above bowl consistent with instructions).For installation behind bulkhead, a spe-cial hand pump option is available (seeillustration on p.9).Particularly quiet and hygienic in opera-tion.Pump can also empty holding tanks, beused as a bilge pump and/or showertray discharge pump.Any type of paper can be used,although tissue is recommended.Virtually no maintenance.Quick release pump cover for easyaccess.Single action operation.Exceptionally sturdy and durable.Full flow valve system.Low water usage.Remote holding tank installation (if cho-sen).A water seal is the only certain andcomplete way of preventing odour fromthe waste pipe and/or holding tank.
Electric – Extra FeaturesOnly marine toilet to offer manual back-up with electric version (see page 17).Extremely quiet in operation.Fully marinised, automatic, adjustabletime switch
4
Exploded diagram of the Lavac Zenith
PRODUCT UPDATENew Thermo-set seal (11) introduced July 1993with no joins or weld points. Cross-sectionbelow showing longer sealing lip conforms bet-ter to contact surface (seat or bowl) forimproved vacuum.
PRODUCT UPDATENew white rubber washer for dome nut.
5
Dimensions and specifications
Lavac Zenith toiletBowl – vitreous china for easycleaning and durabilityPedestal – injection mould uPVC.Outlet can be set to either side or rearof toilet.Seat and Lid – special purposeplastic mouldings.Hinge assembly – injection mouldedacetal. Stainless steel hinge pin.Toilet connections – Inlet 19mm (¾“) bore hose.Discharge 38mm (1½“) bore hose.
Dimensions:
A - 185mm (7.3”) C - 368mm (14.5”)B - 290mm (11.4”) D - 410mm (16.2”)
Lavac Zenith
Zenith Components
Diagram No Part No Description1 TBB7215 x 4 M6 Nuts2 TLZ9021 x 4 Pan bolt washers - small
TLZ9022 x 4 Pan bolt washers - large3 TLZ9022 x 4 M6 x 35 Pan bolt4 TLZ9005 Pedestral base5 TLZ9010 Pan base joint6, 7, 8, 9 TLZ9031 Spigot assembly10 TLZ9025 Zenith pan11 TLZ9065 x 2 Seals for seat and lid12 TLZ9070 Zenith seat13 TLZ9075 Zenith lid14 TLZ9405 Zenith hinge pin15(x2), 16(x2) TLZ9056 Hinge set17(x4), 17a(x2)
Lavac Zenith - Accessories
Part No DescriptionTLZ9096 Clip for pump handle (38)TLZ9310 Diverter (two-way) valveTLZ9460 Bulkhead plate and shroud for U/D pump
6
Exploded diagram of the Lavac Popular
7
Dimensions and specifications
Lavac Popular toiletBowl – vitreous china for easycleaning and durabilityPedestal – injection mould uPVC.Outlet can be set to either side or rearof toilet.Seat and Lid – special purposeplastic mouldings.Hinge assembly – injection mouldedacetal.Toilet connections – Inlet 19mm (¾“) bore hose.Discharge 38mm (1½“) bore hose.
Dimensions:
A - 185mm (7.3”) C - 343mm (13.5”)B - 352mm (13.9”) D - 416mm (16.4”)
Lavac Popular
Popular Components
Diagram No Part No Description4 TLZ9005 Pedestal base5 TLZ9010 Pan base joint51 TLZ8015 x 4 M6 x 50 Pan bolt
TLZ8010 x 4 Plastic coversTLZ8022 x 4 Plastic washerTLZ8021 x 4 Stainless steel washerTLZ8020 x 4 M6 nuts
52 TLZ8025 Popular pan53 TLZ8031 Popular inlet spigot54L, 54R. 55(x2) TLZ8056 Hinge set56 TLZ8065 Popular seat seal57 TLZ8066 Popular lid seal58 TLZ8070 Popular seat59 TLZ8075 Popular lid
Lavac Popular - Accessories
Part No DescriptionTLZ9096 Clip for pump handle (38)TLZ9310 Diverter (two-way) valveTLZ9460 Bulkhead plate and shroud for U/D pump
8
Note:Bulkhead plate and shroud for theU/D pump (makes a neat, flushinstallation – Spares No: TLZ9460,see installation diagram on p.15).
U/D PumpHandle Position T/A Pump
Handle Position
Exploded diagram of Hand Pump
9
Dimensions and specifications
Hand PumpDiaphragm typeInjection moulded plastic bodyStainless steel fastenings and handleAll rubber components of oil resistantnitrile
Lavac Zenith & Popular Hand Pump
Components
Diagram No Part No Description20 TLZ9110 Diaphragm21 TLZ9175 x 8 2BA x 1” Bolts
TLZ9181 x 8 2BA nuts22H TLZ9330 Inlet valve - hand
TLZ9335 Inlet valve plate23 TLZ9320 Front cover24 TLZ9325 Front cover seal25 TLZ9125 Eye bolt nut26 TLZ9100 Top cover complete with valves27 TLZ9340 Outlet valve28 TLZ9345 x 2 Outlet valve screws - long
TLZ9350 x 2 Outlet valve screws - short29 TLZ9115 x 2 Diaphragm plates30 TLZ9120 Eye bolt35 N/A Not available as spares item36 TLZ9406 Rocker arm hinge pin
TLZ9408 x 2 Circlips (rocker arm pin)37 TLZ9450 U/D Rocker arm38 TLZ9265 Pump handle39 TLZ9455 T/A Rocker arm
Exploded diagram of the electric pump – 12&24 Volt
11
Dimensions and specifications
Electric pumpDiaphragm type 12V or 24V DCInjection moulded plastic bodyAlloy crancaseStainless steel crank mechanism withplain bearingConsumption 5 amps at 12v underload. - 5 amp fuse suppliedWeight 4KgFlow / delivery rate 6 gal per min
Lavac Zenith & Popular Electric Pump
Components
Diagram No Part No Description20 TLZ9110 Diaphragm21 TLZ9175 x 8 2BA x 1” Bolts
TLZ9181 x 8 2BA nuts22H TLZ9330 Inlet valve - hand
TLZ9335 Inlet valve plate23 TLZ9320 Front cover24 TLZ9325 Front cover seal25 TLZ9125 Eye bolt nut26 TLZ9100 Top cover complete with valves27 TLZ9340 Outlet valve28 TLZ9345 x 2 Outlet valve screws - long
TLZ9350 x 2 Outlet valve screws - short29 TLZ9115 x 2 Diaphragm plates30 TLZ9120 Eye bolt33 TLZ9421 Crank assembly60 TLZ9290 12V Motor
TLZ9295 24V Motor61 TLZ9185 x 4 M5 x 22mm bolts62 TLZ9156 Crank case
Electric pump
Dimensions:A - 178mm (7”) C - 278mm (11”)B - 223mm (8.8”) D - 225mm (10”)
12
Lavac Zenith
Description Part No Hand pump kit 12 or 24V electricpump kit
TLZ0954 TLZ0952
Hand pump spares kit
Electric pump spares kit
Pan base gasket (5)
Sealing washer for inlet spigot (7)
Rubber washer (17a)
Hinge bush (15)
Seal for seat and lid (11)
Handbook
TLZ0951
TLZ0956
TLZ9010
TLZ9035
TLZ9054
TLZ9060
TLZ9065
TLZLIT
1
-
1
1
2
2
2
1
-
1
1
1
2
2
2
1
Zenith spares kits
Lavac Popular
Description Part No Hand pump kit 12 or 24V electricpump kit
TLZ0854 TLZ0852
Hand pump spares kit
Electric pump spares kit
Pan base gasket (5)
Hinge pad (55)
Seal for seat (56)
Seal for lid (57)
Handbook
TLZ0951
TLZ0956
TLZ9010
TLZ8061
TLZ8065
TLZ8066
TLZLIT
1
-
1
2
1
1
1
-
1
1
2
1
1
1
Popular spares kits
13
Lavac operation
14
Installation – seacocksSiting and installing the seacocksHaving chosen the type of inlet anddischarge seacocks required foryour particular needs, they shouldbe mounted in the hull. We recom-mend Blakes Seacocks for use withour marine toilets. The inlet is19mm (¾“) and the outlet is 38mm(1½“).
The inlet seacock should be about460mm (18“) below the water lineand forward of the discharge sea-cock. On a sailing vessel, the dis-tance below the water line mayhave to be more to allow for heel-ing. The discharge seacock shouldalso be below the water line butneed not be as deep as the inlet.
The location of both seacocks shouldbe convenient for attaching piping toand from the toilet and easily acces-sible for turning off. Ensure that theyare positioned to accept the hosesbefore drilling the holes to accept thefixing bolts.
Fitting the seacocks to the boat.For fibre-glass boats (GlassReinforced Plastic) we recommendthe fitting of a wooden pad, bondedto the hull, slightly greater in diame-ter than the seacock flange and13mm to 19mm (½“ to ¾“) thick(seefig. 1). To ensure watertight joints on
Fig. 1
¾“ INLET SEACOCK WITH STRAINER
CHAMFEREDGE
WOODENPAD
GRPHULL
GRP hulls, a small amount of under-water sealing compound should beput between the inside skin and thispad and also under the seacockflange
For wooden hulls, ensure thatdrilling is carried out in the centre of
a hull plank.
For steel hulls. (see fig. 2, the sea-cocks must not under any circum-stances be bolted directly onto thehull. They should be isolated with agasket and studded with stainlesssteel fittings. This is to prevent elec-trolytic action.
For aluminium (alloy) hulls, specialaluminium seacocks should be used.Plastic seacocks are often used butare not recommended by Lloydsbecause of the possibility of meltingin the event of a fire.
Seacock spigots should be cut off tosuit the outside of the hull. The inletseacock should be flush with the out-side of the hull and a strainer fitted.Similarly the discharge seacockshould protrude to enable it to takethe discharge plate.
Fig. 2
RUBBER orNEOPRENE
STUD
STEEL HULL
PAD WELDEDTO HULL
15
Lavac Installation
Summary
1. INLET SEACOCKShould be mounted forward of thedischarge to avoid recirculatingwaste. We recommend the use ofBlakes seacocks.
2. PUMP (Hand or Electric)Diagram on the right shows a U/Dhand pump installation with U/Dpump plate and shroud. The pump(hand or electric) must be mountedso that the water flow is verticallyupwards through the pump asshown. The bottom of the pumpmust not be mounted at a lowerlevel than the top of the bowl.
3. AIR BLEED VALVEA simple plastic plug with a holedrilled into it. The plug allows airinto the system, preventing siphon-ing and releasing the vacuum whenpumping stops. The size of the holein this valve controls the level ofwater remaining in the bowl. Twovalves with different sized holes areprovided (Spares No. TLZ9251 –the larger the hole, the less waterremains in the bowl.
4. DISCHARGE SEACOCK
5. BOWLThe outlet at the rear of the bowlcan be positioned to the left, right orcentre. This can be very helpful fordifficult installations.
6. U/D PUMPMakes a neat, flush installation.
7. HANDLE CUP
Typical installation
Siting and installing the Lavac
1. The Lavac base should bemounted on a hardwood or fibreglass platform approximately 32mm(¼“) thick. A template should beused for drilling the holes necessaryin the platform.
2. Securing bolts 6mm (¼“) shouldbe used to hold down the toilet. Donot fix the toilet at this point. It isadvisable to wait until the hoses arefixed and installation checked.
3. We recommend the use of rein-forced sanitation grade hose for theLavac installation. Avoid sharpangled or acute bends in either the
16
Lavac Installation Handle position (angle of operation) and/or outletdirection can be varied by rotating pump body(26) relative to back cover (35) (See explodeddiagram p.8).If back cover (35) is rotated ensure air bleed holein back cover is re-drilled at lowest point.
DIRECTION OFOUTLET
therefore all hose clips must betight.
8. An important part of the Lavacinstallation is the air bleed valvewhich has to be located at the topof the loop of the inlet pipe. Drill a5mm (1/18”)diameter hole at thetop of the curve of the inlet pipe Ifthe top of the inlet pipe is in aclothing locker, ensure that theclothes do not obstruct the airbleed valve. Similarly, if the hoseis hard up below the deck, drill thehole slightly to one side at the topof the loop. For installations on orabove the water line, insert thewhite plastic bleed plug.For installations below the waterline, use the black plastic plug.(Set of bleed plugs TLZ9251).
9. Attach the self-adhesive oper-ating instructions to the bulkheadnear the pump. We recommendthat a suitable rubber stop isplaced on the bulkhead behind theLavac unit to avoid possible dam-age to the lid when opened.
inlet and, particularly, the outlethoses. If it is completely unavoid-able to use right angled fittings inthe outlet hose, then rigid plastic fit-tings should be used having aninside radius of not less than 31mm(2“). Do not use sharp angledplumbers fittings which can easilycause a blockage.
4. Establish a position for the pumpwhere the pump inlet is no lowerthan the bowl top.
5. Bolt or screw the pump in posi-tion using 6mm (¼“) diameter boltsor screws ensuring that the flowarrow on the pump is vertically upor certainly not more than 45° fromthe vertical.IF THE PUMP IS MOUNTED INANY OTHER WAY THE INSTALLA-TION WILL BE INEFFICIENT INOPERATION AS THE INLET VALVECANNOT SEAL EFFECTIVELY.
6. Cut the 38mm (1½“) diameteroutlet hose to the lengths required.Be sure to allow enough hose fromthe top of the pump to take the loopabove the waterline at maximumheel of the boat. For motor vesselsthis is high enough at maximumangle of roll. Attach the two cutlengths of hose from the bowl to thebottom (inlet) of the pump and fromthe top of the pump (outlet) to theoutlet seacock.
7. Connect the 19mm (¾“) boreinlet hose to the bowl inlet, havingallowed for a loop similar to the outlet(see point 6) and attach the inlethose to the inlet seacock.PEASE NOTE: It is absolutelyessential that all joints are 100%sealed. No air leakage is permissible
17
Lavac Electric pump Installation1. Connect up wiring as indicated in thediagram. The time switch should bemounted through the bulkhead so thatonly the front flange with push button andshroud are visible to the user. Use onlystainless steel screws.
2. The time switch is set for 30-45 sec-onds. If you wish to adjust the operatingtime (inlet pipe length will vary betweeninstallations), turn the small screw in thecentre of the back of the switch veryslightly in a clockwise direction to length-en the time and anti-clockwise to reduceit (time switch is adjustable betweenapprox 1 second and 10 minutes).
3. Ensure when mounting the pumpthat the flow arrows are facing upwards.Do not mount in a horizontal position.Also ensure that the pump is no lowerthan the top of the bowl.
4. WARNING. Do not operate theswitch while using the toilet. As a precau-tion, mount the switch in such a positionthat children cannot reach it until afteruse.
The Electric Lavac can be fitted witha standby manual pump to provideemergency back up. It is easy toupgrade existing hand toilets to elec-tric or add a standby pump to elec-tric toilets.
Holding Tanks – GeneralOptions Recirculating pump out – often usedfor a conversion installation wherethe toilet compartment is sufficientlyroomy. The holding tank is usuallyintegrated with the toilet head, butwith the Lavac used in a recirculat-ing system the holding tank can beremote.
Fresh Water Flush with Pump-OutHolding Tank – probably the mostacceptable system to the user.Allows for a larger tank installation,as the tank can be positioned any-where in relation to the toilet head.
Holding Tank CapacityIf sink and shower waste is alsobeing contained the holding tankmust be substantially larger. Usedwith care, a shower will requireabout three gallons each time it isused. Obviously both sink andshower waste quantities dependentirely on how the facilities areused, as well as the frequency ofuse. The size of a holding tank isentirely dependent on the berth/sizeof the boat and anticipated durationbetween pump-outs. A holding tankcan never be too large but it caneasily be inconveniently small.Restriction on size depends onavailable space for installation andeffect on the boats trim. The follow-ing formula will provide an approxi-mate guide to the minimum size oftank which is acceptable:
Berths x days between pump-outx Y = gallons capacity of tank.
For recirculating systems factor Y=0.5
For fresh water flush systems factorY = 2.5These calculations assume low wateruse toilets are being used.
Materials If a holding tank system is beingconsidered, some careful thoughtmust be given to the design andconstruction of the tank. Fourmaterials are commonly used forholding tank construction,polypropylene, glass fibre, stain-less steel and galvanised steel.Polypropylene – the smooth inter-nal and external finish of thismaterial has the benefit of prevent-ing matter from adhering to thewalls of the tank and at the sametime presenting a clean, trimappearance.Glass Fibre – provides consider-able flexibility in design and iseasy to alter during or after instal-lation, should the need arise.Stainless Steel – is strong andresistant to corrosion but is expen-sive, in both material and con-struction.Galvanised Steel – provides thecheapest solution but is not totallycorrosion resistant. Once corrosionstarts it spreads rapidly.
Flexible TanksFlexible tanks are very easy toinstall in retrofit situations. Ideal oncraft where holding facility is sel-dom used, but two points shouldbe considered carefully:(i) If the boat is likely to encountermuch sea movement then flexibletanks are prone to wear and chaffe(ii)some materials, although fluid-tight, will omit odour and a suitablegrade flexible tank must be used.
19
Holding Tanks – Lavac
Economy of Flushing WaterEconomy of flushing water is a valu-able Lavac characteristic for holdingtank installations. This is also impor-tant when flushing water is beingdrawn from the craft’s own water tank.Using the on-board fresh water supplyfor flushing should be seriously con-sidered. It prevents scaling in the sys-tem from salt water and dirty/oily waterentering the bowl. The Lavac usesapproximately only 3 pints of flushingwater per operation. With the electricLavac, the quantity of flushing watercan be controlled accurately by thetime switch. This may be helpful forowners frequently entertaining visitorsinexperienced on boats. Two timeswitches can be used if a long andshort flush option is thought worthwhile.
FlexibilityLavac provides the facility to site
tanks anywhere in the boat. Therefore,as well as making maximum use ofthe tank capacity, because of theeconomy of flushing water used, theholding tank can be housed wherespace is less critical, allowing a largertank to be installed than is possiblewith some other systems. With theLavac system it is practical to install ahigh tank. Why not consider, for exam-ple, a full height floor to roof bulkheadtank? (This can be in conjunction witheither sea water or fresh water flushsystems).
Diverted Pump ActionIn conjuction with a two-way valve, itcan carry out other tasks. See figs 2, 3and 4 on pages 21 and 22. Fig. 5shows how this saves the cost of aseparate pump and hull fitting.
Ideal for Recirculating SystemAlthough the Lavac has ideal featuresfor fresh water flushing systems, inextreme circumstances it may be pre-ferred to minimise the holding tanksize and operate a recirculating sys-tem. Lavac, incorporating a sealedseat and lid to the bowl, reducesodour considerably below levelsencountered with other recirculatingtoilet systems. If the Lavac is beingused on a recirculating principle, theflushing water pick up pipe, in theholding tank, must be surrounded by afine aluminium or brass gauze filter.
Vacuum Fragments WasteThe vacuum fragments waste as itpasses through the base opening.Solid matter will remain in suspensionin the tank, thus allowing more effi-cient tank emptying. This eliminatesthe need for a macerator. Maceratorsare best avoided if possible becausetheir mechanically operated cuttingblades can be jammed with even smallobjects. Macerators are also verynoisy!
20
Holding Tank Plumbing
Key Points
For all systems where pump-outvia deck fitting, or via seacock,is not required either can beomitted.If Holding Tank is above thewaterline no pump is requiredfor discharge to sea, i.e. openseacock to drain, close to hold.(Also open seacock to allow dis-charge to sea via the tank,direct from toilet. Tank outletmust be installed at bottom oftank and fall continuously toseacock).When inlet or Outlet Hoses areplumbed overboard, to a below-waterline position, they must belooped above the waterline toprevent siphoning (If toilet isbelow the waterline).
Ball Check Valve for ¾“ bore hose(only required if draw is more than36“ below toilet) or vented looprequired if toilet is below waterline.
Useful statistics
One cubic foot contains 6 gallons.One gallon contains 1/6 cubic feet.One gallon of water weighs 10 lbs.
Fig. 1
Suggested Systems
1 - For craft permanently onwaters where overbard dischargeis prohibited. This is a basic sys-tem. Use of a dock side marinapump out station is used or a DIYoutboard pump can also dischargethe holding tank.
A Toilet discharge flowB Pump-out flow to quayC Discharge to sea
1. Vent/breather pipe connect to 1”ID hose
2. Microvent filter (see p.20)3. Rinse-out facility connect to ID
hose4. Ball check valve or vented loop.5. Seacock
Pump-out deck fittingVented Loop
‘T’ ConnectionLavac Pump. Handand/or Electric
Self pump-outinboard pumpHand orElectric
Flushwater intake
B/C
HOLDING TANK
LAVACTOILET
21
Fig. 2
2 - For craft visiting waters whereoverboard discharge is prohibited. This system is simple to oper-ate. Use of quay side marinapump out station is not restrict-ed by the on board, in line,pump. Holding tank contentscan be drawn through it.
A Toilet discharge flow B Pump-out flow to quayC Discharge to sea
1. Vent/breather pipe connected to1½“ ID hose.
2. Microvent filter – see page 20.3. Rinse-out facility, connect to ¾“
ID hose.4. Ball check valve or vented loop.5. Seacock.
Pump-out deck fitting
VentedLoop
‘Y’ Connectors
Lavac Pump.Hand and/or Electric
Self pump-outinboard pumpHand orElectric
Flushwater intake
C/B
HOLDING TANK
LAVACTOILET
DiverterValve
Fig. 3
3 - For craft requiring toilet dis-charge to sea or holding tankand pump-out of holding tankusing the one toilet pump. Only installations with Lavactoilets can operate this system.
A Toilet discharge flow B Pump-out flow using Lavac
pumpC Pump-out flow using quay side
pumpD Discharge to sea
1. Vent/breather pipe connected to1½“ ID hose.
2. Microvent filter – see page 20.3. Rinse-out facility, connect to ¾“
ID hose.4. Ball check valve or vented loop.5. Seacock.
Pump-out deck fitting
VentedLoop
A/B/DLavac Pump.Hand and/or Electric
Flushwater intake
HOLDING TANK
LAVACTOILET
DiverterValve
B/C/D
A/B/C/D
B/C
/D
Pump-out deck fitting
VentedLoop
A/B/D
Lavac Pump. Handand/or Electric
Flush water intake
HOLDINGTANK
LAVACTOILET
DiverterValve
C/B
A/B/D
B/C/D
B/D
B/C/D
‘T’ or ‘Y’ connection
‘Stop Valve
4 - An alternative to fig.3. This sys-tem provides a self pump-out facility toshore or sea, suing the one toiletpump. Only installations with Lavactoilets can operate this system. Whenbeing pumped out by quayside facilitythis arrangement avoids the tank con-tents being drawn through the pumpand uses only one sewage pipe con-nection to the tank.A Toilet discharge flow B Pump-out flow using Lavac pumpC Pump-out flow using quay sidepumpD Discharge to sea
1. Vent/breather pipe connected to1½“ ID hose.
2. Microvent filter – see p. 203. Rinse-out facility, connect to ¾“
ID hose.4. Ball check valve or vented loop.5. Seacock.
Fig. 5
To sea
LAVACTOILET
2-WAYVALVE
PUMP
FromBilgeShowerBasinEtc.
DISCHARGE
Holding Tank – Accessories1. Two-way valve(Spares No, TLZ9310)The two-way valve in the systemsabove shows how, in conjunctionwith the separate pump on theLavac toilet, bilges, showers,washbasins, holding tanks, etc,can be emptied. Exemplified in fig.5, this clearly saves the cost ofseparate pump and hull fitting. Thetwo-way valve we supply has apositive action, is almost mainte-nance free and has no parts towear or corrode.
2. Holding Tank Breather FilterMicrovent Filter. This activated Carbon Filterabsorbs noxious and unpleasant odours and gases.The microvent filter is installed either vertically orhorizontally within the breather pipeline in such away as to minimise the possibility of it coming intodirect contact with solid or liquid contents inside theholding tank. The carbon filters are easily replacedwhen their time life has expired.
Fig. 6
‘T’ or ‘Y’ connection
‘T’ connection
22
Fig. 4
23
Operation
Manual pump operation
1. To flush the toilet, close theseat and lid and give 8-10steady pulls using the fullmovement of the handle.Pause for five seconds andthen continue pumping asbefore for a further 5-6 strokes.The higher the base of thebowl is above the waterline,the more strokes are needed.(Also see note 8, page 16).
2. It is essential that a sufficientnumber of strokes are used toclear the system completely.Use the full movement of thepump handle. Avoid usingshort jerky strokes. The num-ber of strokes required willvary according to the length ofthe hoses.
NOTE: TO LEAVE TOILETBOWL EMPTY OF WATER,LIFT SEAT (13) AND THENOPERATE PUMP.
Electric pump operation
1. To flush the toilet, close the seatand lid and press the push but-ton fully in and release it.
2. The Lavac electric pump,whether incorporated in theLavac electric toilet or used inde-pendently as a pump for fluids,should never be operatedagainst a seacock or any othertype of valve that is closed orpartially closed as this maycause costly damage to thepump. (Note: similar circum-stances can arise if the hose isblocked – see section on Checkpoints.)
3. Where a two-way valve or divert-er valve is used in the system,the pump should be switched offwhilst the direction of flow isbeing changed as the valve hasa midway closed position.
4. Similarly where two or moretwo-way diverter valves are inthe system, ensure that bothvalves are set for a free dis-charge before starting the elec-tric pump.
HANDVERSION
ELECTRICVERSION
1 2
24
Toilet cleaners
Seat and lidOnly use soapy water. Difficultstains can be removed with alco-hol, e.g. methylated spirits.
PumpA useful approach to remove scalebuild-up is to introduce a solutionof vinegar into the pump (by put-ting it into the bowl and with the lidopen operate the pump for a fewstrokes). Leave for 24 hours andthen flush thoroughly with cleanwater.
BowlThe best cleaner for a marine toiletis frequent flushing, provided thatthe seawater is reasonably clean.Do not use harsh, abrasive clean-ers and avoid using domesticcleaners that may contain bleach.Flushing through with soapy freshwater from time to time is a goodidea. This will help in delayingscale deposit and keep the neo-prane valves in the pump supple.
Day to day points to remember
1. Ensure that the operatinginstructions are mountedwhere your guests will seethem.
2. Always fully flush the toilet.
3. Occasionally flush through withsoapy water.
4. Put a notice on the toilet if youturn off the seacocks. You mayburst a pipe or damage the toi-let otherwise.
5. Close the seacocks when youleave the boat. This will keepthem free and is seamanlikepractice.
Maintenance
Avoidance of frost or cold damage
1. When laying up the boat for thewinter, ensure that all the waterhas been pumped from the sys-tem to avoid frost damage. Theoutlet seacock should beclosed and the discharge hosedisconnected from it. Operatethe pump into a bucket toempty remnants of water.
2. Close off the inlet seacock, dis-connect the hose and drain itoff.
3. During the laying up period,check the interior of the pumpand remove any scale that hasaccumulated and also checkthat the hole in the bleed valveis clear.
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Replacing the perishablepump parts
1. Unscrew the front cover (23)and loosen eyebolt nuts (25).Photo 2Replace the front cover seal(‘o’ ring) (24).
Maintenance – Perishable parts
Replacing the seat and lid seals
1. Hook one end of the sealunder the rim of the lid, stretchthe seal around the rim andclip under all way round.Photo 1.
2. Repeat for the seat.
2. Unscrew the 8 screws (21)around the edge of the octago-nal pump body (26) andremove.Photo 3.
Photo 1
Photo 3
Photo 2
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Maintenance – Perishable parts
3. Unscrew the eyebolt (25) nutand remove diaphragm (20complete with diaphragmplates (29) Replace diaphragm(20).
5. Unscrew 2 short and 2 longscrews (28) to remove the out-let valve (27) Replace.
6. Re-assemble in reverse order,replacing all the stainless steelscrews (21 & 28). When re-assembling the pump ensureall screws are tight. If air canbe drawn into the pump, thetoilet will not operate.To prevent leaking it is advis-able to use a clear siliconesealant on all screws andjoints.Spares kits, detailed on pages12 include the perishable partsneeded.
4. The inlet valve and plate (22Eor 22H) simply clips out.Replace.
photo 4
Photo 5
Photo 6
27
Operational Solutions
Fault Possible cause SolutionNo flushing waterdrawn in whenbowl emptied.
Inlet seacock closed.
Failure of vaccum
Inlet hose loopedgreater than 5 feet(1.5m) above waterline.
Inlet pipe or seacockinlet outside the boatblocked.
Open inlet seacock and check that theoutlet seacock is open as well.
When the seat and lid are closed and thepump operated, the bowl should besealed for around 30 seconds, i.e. youcannot lift the lid. Anything less indicatesexcess air bleeding into the system.Check the condition of the seat and lidseals.Are all the hose clips tight?Check air bleed plug is in place and thatthe hole is not too large.
In this instance it may be necessary to fit anon-return valve in the inlet hose justabove the water line.This maintains a head of water to facilitatethe initial syphoning of flushing water.
In this condition the bowl will seal. Checkseacock by closing it, removing the hoseand then turning on.Check inlet hose for blockage.
Pump will notempty the bowland is hard tooperate
Closed seacock,blocked hose orblocked pump.
Stop pumping.The pump will be hard and then impossi-ble to operate as it builds up pressure.You could easily blow a hose connectionoff.Check the hose for blockage from bowl topump and from pump to seacock.The pump is checked via the openingfront cover. If pressure has built upthrough excess pumping, be very carefulto ease the front cover slowly.Do not attempt to remove it completelyuntil the pressure has gone.
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Operational Solutions
Fault Possible cause SolutionPump handleeasy to operatebut bowl will notdischarge
Pump blockage
Scale build up inpump.
Pump lost prime
Diaphragm split
Check through the front cover for blockageholding the inlet valve open.
This scale, which builds up over a variabletime depending on the salinity and temper-ature of the water (warm and very saltywater is the worst condition), will graduallyreduce pump efficiency to the point of notworking.The scale can be removed by physicallychipping off after stripping the pump or itcan be disolved in vinegar if the parts areleft to soak.Scale will also build in the discharge hose.This is best removed by physically bendingand ‘working’ the pipe so that scale is dis-lodged and will fall out. If it is possible toremove the hose this job is much easier.
Pump very rapidly to see if you can regainprime, or remove front cover and pour asmuch water as possible into the pump andretry. Loss of prime may be due to lowervalve not seating properly and water drain-ing from the pump back to the bowl.
Check diaphragm and replace if necessary
A bad smell isapparent when thetoilet is first usedafter the boat hasbeen left for sometime.
Sulphur dioxide.
Algae deposit in theinlet hose.
When the toilet is first used, the stale airfrom the inlet is drawn into the boat.Give the system several good long flush-es immediately you go aboard.If you can remove the hose, filling it andleaving it to soak in disinfectant will help.Pumping disinfectant through thepump will NOT help because the prob-lem originates in the inlet hose.
Too much waterleft in bowl afteruse.
Diameter of hole inair bleed valve needsincreasing
Use a hot needle to slightly increase holediameter of the air bleed valve or replaceair bleed plugs.
29
Operational Solutions
Fault Possible cause Solution
Electric pumpdoes not flus sys-tem properly
Pump not runninglong enough.
Incorrect inle valvefitted.
Pump not mountedvertically.
The pump should run for a minimum of 1minute and possibly longer in installationswhere the pipe runs are unusually long.Running time can be increased/ decreasedby fractional turns of the small screw locat-ed in the centre rear of the time switch.Viewed from rear of time switch, clockwiseadjustment increases running time.Only a few degrees of movement shouldbe necessary.
The electric pump is fitted with a specialweighted inlet flap valve and if this isreplaced by the normal hand pump valve itcan, though not invariably, detract frompump efficiency.
Please check that the arrow on the pump ispointing vertically upwards or that at worst,not more than 45° from vertical.
Leakage is occurring past diaphragm intoback of pump.If the pump body is mounted with the han-dle vertical the leakage will quickly manifestitself as a drip through the air bleed hole atthe back of the pump.Tighten eyebolt nut (25).For this operation remove front cover (23)as explained in Point 2, Page 25. Siliconesealant is recommended. It should beapplied to thread of eyebolt before the nutis tightened onto itIf problem continues, check diaphragm (20)for splitting and replace.
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Blockages in the pump
If a blockage occurs in the pump, first pour half a bucket of water in thebowl and then, with the lid open, pump with even firm strokes until thewater leaves the bowl.This should clear the pump but repeat if necessary and then close the lidand pump again to replace the correct amount of water in the bowl.
If the pump will not operate and empty the bowl, remove the front cover ofthe pump. This is a quick release fitting that has to be turned in an anti-clockwise direction to unscrew. A bucket should be held below the pumpwhilst doing this as the contents of the pump will escape. (Note: the oldMark 3 pump has fixing screws to the front cover.)
Check that the inlet and outlet valves are not being held open by anobstruction. If so, remove the obstruction. Replace the front cover andseal and check the operation of the pump. If it still does not operate (i.e.empty the bowl with the lid open) it will be necessary to remove the pumpbody from the pump base by unscrewing the 8 bolts around the octagonperimeter and replacing the valves. See page 25-26 ‘
When re-assembling the pump, ensure that all screws are tight (not over-tight). If air can be drawn into the pump, the toilet will not operate.
