Lavac · Marine toilet

Lavac Zenith & Popular

The Lavac is a British vacuum toilet: a china bowl with a sealed seat and lid, and a separate diaphragm pump on the bulkhead, either a Henderson Mk 5 type hand pump (T/A on the bulkhead or U/D behind it) or a 12/24 V electric pump. With the lid shut, pumping empties the bowl and the vacuum draws in the rinse water, so the only moving parts sit in the pump and the toilet works above or below the waterline. The Zenith is the original model; the Popular is a lighter, cheaper version with the same pump, pedestal base and pan joint but its own bowl, seat, seals and hinges. The maker, Blakes Lavac Taylors, is dormant: lavac.co.uk now points to Spares Marine in Kingswear, which sells the spares, no longer lists a complete Zenith and offers the Popular bowl kit TLZ0809 as the replacement for both models.

Manuals & documents
Wear parts & part numbers
Service intervals
Specifications
Good to know
Fitted in
On the marketplace

Manuals & documents

The maker, Blakes Lavac Taylors, is dormant and lavac.co.uk now points to Spares Marine, so the handbook and parts finders link to Spares Marine’s copies; older editions and the maker’s FAQ are archived copies of its former website. We host no manuals or drawings.

Lavac Zenith & Popular handbook: installation, exploded drawings, parts lists, spares kits, maintenance Operation manual sparesmarine.co.uk · PDF · EN
The same handbook as published by Blakes Lavac Taylors (archived 2004) Archived maker page web.archive.org · PDF · EN
Lavac Zenith handbook, revised March 2004: old and new electric pump, cruising spares kits, weights Archived maker page web.archive.org · PDF · EN
Zenith base and bowl: parts finder Parts catalogue sparesmarine.co.uk · PDF · EN
Popular base and bowl: parts finder Parts catalogue sparesmarine.co.uk · PDF · EN
Hand pump (T/A and U/D): parts finder Parts catalogue sparesmarine.co.uk · PDF · EN
Electric pump 12/24 V: parts finder Parts catalogue sparesmarine.co.uk · PDF · EN
Spares Marine toilet downloads (Lavac manuals and parts finders) Manual portal sparesmarine.co.uk · EN
Lavac Zenith spares with diagram numbers (Spares Marine shop) Manual portal sparesmarine.co.uk · EN
Lavac Popular spares with diagram numbers (Spares Marine shop) Manual portal sparesmarine.co.uk · EN
Lavac FAQ: troubleshooting and electric run times (archived 2001) Archived maker page web.archive.org · EN

Wear parts & part numbers

Part	OEM number	Also fits	Note
Service kit	`TLZ0951`^1,2,3,4	—	Hand pump (T/A or U/D) on Zenith and Popular; Spares Marine also lists it for the Henderson Mk 5 pump. Contains diaphragm TLZ9110, front cover seal TLZ9325, inlet valve TLZ9330, inlet valve plate TLZ9335 and outlet valve TLZ9340. Not for the very old Mark 3 pump (screwed front cover).
Service kit	`TLZ0956`^1,2,5	—	Electric Zenith and Popular (12 V or 24 V) with the original Lavac pump: the same parts as TLZ0951, but with the weighted electric inlet valve instead of the hand valve. For the newer TMC pump take TLZ0956NEW.
Service kit	`TLZ0956NEW`⁶	—	Only for Lavacs fitted with the newer TMC replacement pump TLZ9180/TLZ9190; contents not listed. One source (Spares Marine).
Spares kit	`TLZ0954`^1,2,7	—	Zenith with T/A or U/D hand pump: kit TLZ0951 plus pan base joint TLZ9010, inlet spigot washer TLZ9035 (1 in the handbook, 2 at Spares Marine), 2 hinge bushes TLZ9060, 2 seat/lid seals TLZ9065 and 2 rubber hinge washers TLZ9054.
Spares kit	`TLZ0952`^1,2,8	—	Zenith electric (12 V or 24 V): electric pump kit TLZ0956 plus the same pan joint, spigot washers, hinge bushes, seat/lid seals and hinge washers as TLZ0954.
Spares kit	`TLZ0854`^1,9	—	Popular with T/A or U/D hand pump: kit TLZ0951 plus pan base joint TLZ9010, seat seal TLZ8065, lid seal TLZ8066 and hinge pads TLZ8061 (2 in the handbook, 1 at Spares Marine).
Spares kit	`TLZ0852`^1,10	—	Popular electric: electric pump kit TLZ0956 plus pan base joint TLZ9010, seat seal TLZ8065, lid seal TLZ8066 and hinge pad(s) TLZ8061.
Seat & lid seal	`TLZ9065`^1,2,11,12	—	Zenith only: the same seal fits seat and lid, so a full change takes 2. One-piece thermo-set seal since July 1993.
Seat & lid seal	`TLZ8065` · `TLZ8066`^1,13,9	—	Popular only: seat seal TLZ8065 and lid seal TLZ8066; now also sold together as TLZ8067KNEW.
Seat & lid seal	`TLZ8067KNEW`^14,15	—	Popular: seat and lid seal as a set; the current parts finder shows it in place of TLZ8065/TLZ8066. One source (Spares Marine).
Diaphragm kit	`TLZ9110` · `TLZ9120` · `TLZ9125`^1,16,17,3,2	—	Diaphragm TLZ9110 (hand pump and original electric pump, Zenith and Popular; in kits TLZ0951/TLZ0956), with eye bolt TLZ9120 and eye bolt nut TLZ9125, which clamp it between the diaphragm plates. A loose nut lets water drip from the back of the pump.
Pump cover O-ring	`TLZ9325`^1,16,18	—	Seal of the quick-release front cover, hand pump and original 12/24 V electric pump, Zenith and Popular; in kits TLZ0951/TLZ0956.
Flapper valve	`TLZ9330` · `TLZ9335`^1,16,19,2,3	—	Inlet (lower) flap valve TLZ9330 of the hand pump, held by the inlet valve plate TLZ9335 (the plate is also used in the electric pump); both are in kit TLZ0951. Never fit the hand valve in an electric pump: it needs the weighted valve.
Flapper valve	`TLZ9105`⁵	—	Weighted inlet flap valve of the original electric pump; the number appears only in the contents of kit TLZ0956. One source (Spares Marine).
Pump outlet valve	`TLZ9340`^1,16,3	—	The upper valve, for the hand and electric pump, Zenith and Popular; held by 2 long screws TLZ9345 and 2 short TLZ9350. In kits TLZ0951/TLZ0956.
Pump handle	`TLZ9265`^1,16,20	—	Stainless handle for the T/A and U/D hand pump; stowage clip TLZ9096.
Pump assembly	`TLZ9090`²¹	—	Complete T/A hand pump (on the bulkhead) with handle TLZ9265, Zenith and Popular. One source (Spares Marine).
Pump assembly	`TLZ9095`²²	—	Complete U/D hand pump (behind the bulkhead) with handle TLZ9265, Zenith and Popular; bulkhead plate TLZ9460 sold separately. One source (Spares Marine).
Pump assembly	`TLZ9180` · `TLZ9190`^23,24	—	TMC replacement electric pump, 12 V / 24 V, now the pump for electric Lavacs; service kit TLZ0956NEW. One source (Spares Marine).
Motor	`TLZ9290` · `TLZ9295`^1,17,2	—	Motor of the original Lavac electric pump, 12 V / 24 V; brush set TLZ9475 (2004 Zenith handbook).
Bowl gasket	`TLZ9010`^1,2,25,15,26	—	Pan base joint between bowl and pedestal, Zenith and Popular; in all universal spares kits. Zenith pan bolt (M6 × 35): TLZ9015 in the current parts finder; the handbook misprints it as TLZ9022, the number of the large washer. Popular bowl: TLZ8025 in the handbook, TLZ8026 in the current parts finder, so check before ordering.
Port fittings	`TLZ9031` · `TLZ8031` · `TLZ9035`^{1,25,15,27,28,2,29}	—	Bowl inlet spigot for the 19 mm flushing hose: TLZ9031 on the Zenith, TLZ8031 on the Popular. TLZ9035 is the sealing washer of the Zenith spigot (in the Zenith universal kits).
Vent valve	`TLZ9251`^1,2,30	—	Set of two air bleed plugs for the top of the inlet loop, Zenith and Popular: white for toilets on or above the waterline, black/brown below it. The larger the hole, the less water stays in the bowl.
Hinge set	`TLZ9056`^{1,25,31,32,33}	—	Complete Zenith hinge set; single parts: hinge bush TLZ9060, rubber hinge washer TLZ9054 (white washer under the dome nut since 1994), hinge pin TLZ9405.
Hinge set	`TLZ8064`^34,15	—	Popular, new-style hinge set; Spares Marine says it replaces diagram nos. 54L, 54R and 55 (the handbook lists hinge set TLZ8056 and hinge pad TLZ8061). One source (Spares Marine).
Seat & lid	`TLZ9070` · `TLZ9075`^1,2,25,35	—	Zenith seat TLZ9070 and lid TLZ9075; Spares Marine also sells both with seals as TLZ9068.
Seat & lid	`TLZ8068`^36,15	—	Popular seat and lid complete with seals and hinge set (handbook: seat TLZ8070, lid TLZ8075). One source (Spares Marine).
Protective cover plate	`TLZ9460`^1,2,37	—	Bulkhead plate and shroud for the U/D hand pump, Zenith and Popular, for a flush finish on the bulkhead.
Hose	`TLZ9275`²	—	White odour-resistant 19 mm (¾ in) inlet hose, offered in the 2004 Zenith handbook for Zenith and Popular; the outlet needs 38 mm (1½ in) hose.

Numbers checked against the sources below on 13 October 2026. Always confirm against your serial number and exact type before ordering.

Service intervals

Task	Interval
Full service	At every lay-up: open the pump, remove scale and check that the hole in the air bleed plug is clear; descale with vinegar as needed (left in for 24 h, or soak the parts)^1,2,38
Pump seals	No fixed interval: renew the pump wear parts with kit TLZ0951 (hand) or TLZ0956 (electric) when the pump loses its prime, drips from the back or the bowl will not empty^1,2
Gaskets	On condition: after a flush the lid should stay sucked shut for about 30 s; if it lets go sooner, check the seat and lid seals, the hinge adjustment (seat and lid flat on the rim) and the hose clips^1,2
Fresh-water wash	From time to time: flush through with soapy fresh water to slow scaling and keep the pump valves supple; no bleach or abrasive cleaners¹
Winterising	At every winter lay-up: close the outlet seacock, take the discharge hose off and pump the system empty into a bucket; close the inlet seacock, take its hose off and drain it^1,2

From the Lavac Zenith & Popular handbook and the 2004 Zenith handbook. Lavac gives no hour-based intervals: the pump is serviced at lay-up or when it shows wear. Electric models: the handbook sets the time switch to 30–45 s in one place and asks for at least 1 min in another, and the old Lavac FAQ gives other times again, so set the run time until the bowl clears on your boat.

Specifications

Models	Zenith: TLZ0901 (T/A hand pump), TLZ0902 (U/D hand pump), TLZ0903 (12 V electric), TLZ0904 (24 V electric), TLZ0909 (without pump). Popular: TLZ0801, TLZ0802, TLZ0803, TLZ0804, TLZ0809 in the same order^11,13,39
Versions	Zenith and Popular share the pump (hand or electric), the pedestal base TLZ9005 and the pan base joint TLZ9010; bowl, seat, lid, seat seals and hinges differ. The kits do not fit the very old Mark 3 hand pump (screwed front cover)^{1,25,15,40,2,3,4}
Type	Vacuum toilet with a separate single-diaphragm pump (nitrile rubber parts): hand pump T/A on the bulkhead or U/D behind it, or a 12/24 V DC electric diaphragm pump with an adjustable time switch^1,2
Years built	Lavac design from the 1960s; under Blakes from 1969, Blakes Lavac Taylors (Warsash) from 1999. The Popular is still sold; Spares Marine no longer lists a complete Zenith and offers the Popular bowl kit TLZ0809 as its replacement^41,2,42
Dimensions	Zenith: pedestal width 185 mm, height 290 mm, width 368 mm, depth 410 mm. Popular: 185 / 352 / 343 / 416 mm. Hand pump: 170 × 200 × 140 mm¹
Inlet hose	19 mm (¾ in) ID reinforced sanitation hose, with an air bleed plug at the top of the inlet loop¹
Discharge hose	38 mm (1½ in) ID reinforced sanitation hose; avoid sharp bends, and where a right angle cannot be avoided use a rigid plastic sweep bend, not a plumbing elbow¹
Flush water	About 3 pints (roughly 1.7 l) per flush; on electric models set by the time switch¹
Pump strokes	8–10 full strokes with seat and lid closed, pause 5 s, then 5–6 more (14–16 in all); more if the bowl sits well above the waterline¹
Current draw	Electric pump: 12 or 24 V DC, about 5 A at 12 V under load; 5 A fuse supplied^1,2
Flow rate	Electric pump: about 6 gal/min¹
Control	Electric models: push button with a time switch, adjustable from about 1 s to 10 min; set the run time so the bowl clears on your installation^1,2
Weight	Zenith with hand pump 9.4 kg; electric pump 4 kg (2004 Zenith handbook: 4.5 kg)^2,1
Mounting	Base on a platform with four 6 mm (¼ in) stainless bolts; pump with four 6 mm bolts, flow arrow vertical (at most 45° off) and the bottom of the pump no lower than the top of the bowl; outlet can face left, right or rear¹

Good to know

When a Lavac no longer flushes, it is usually a vacuum leak, not the pump. Pump with the lid shut, then try to lift it: it should stay sucked down for about half a minute. If not, fit new seat and lid seals and check that seat and lid sit flat on the rim.¹
The seat and lid seals are the cheapest fix with the biggest effect, so carry a spare pair: TLZ9065 for the Zenith (one size for both), TLZ8065/TLZ8066 or the set TLZ8067KNEW for the Popular. The seal simply hooks under the rim and is stretched round.^1,14
The air bleed plug at the top of the inlet hose sets how much water stays in the bowl: the larger the hole, the less water. Too much water left means the hole is too small or blocked; no rinse water drawn in can mean the plug is missing.¹
If the pump drips from the back, the diaphragm eye bolt nut is loose or the diaphragm is split: tighten the nut first, with a smear of silicone on the thread, before you change the diaphragm. When rebuilding, tighten all eight body screws evenly and seal them; a pump that can suck air will not flush.¹
Electric Lavac: never run the pump against a closed seacock or diverter valve, and use the weighted electric inlet valve, never the hand-pump valve. If the bowl is not cleared, lengthen the run time slightly with the small screw on the back of the time switch.^2,1
A bad smell on the first flush after a few weeks away comes from the inlet hose, not the pump. Give several long flushes when you come aboard; pumping disinfectant through the pump does not help.¹

Fitted in

Boats whose builder lists it as standard or optional equipment:

Contessa 32 — Lavac (1970s brochure: Lavac marine WC on a Formica base, closed off by a PVC screen and a sliding door)

On the marketplace

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Sources

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