Jabsco · Water pump

Jabsco PAR-MAX pressure pumps

Jabsco’s PAR-MAX pumps are the small diaphragm pressure pumps that feed the fresh-water taps on most cruising yachts: a DC motor drives a wobble plate with three or four pistons under a diaphragm, a built-in pressure switch starts the pump when a tap opens and stops it at the cut-out pressure, and the pump primes from dry and tolerates running dry. The 31295 and 31395 series (PAR-MAX 1.9 and 2.9 on Xylem’s website, PAR-MAX 2 and 3 on the data sheets) are the compact three-chamber pumps for one or two outlets; the four-piston 31600 (PAR-MAX 3) and 31620 (PAR-MAX 4) serve three outlets or more and share one manual and one set of service parts. Jabsco belongs to Xylem; the current 31295/31395 models end in -3A and replace the older -0092/-0094/-0292 numbers. The PAR-MAX 1, the HD3–HD6 and the PAR-MAX Plus are different pumps and not covered here.

Manuals & documents

The links go straight to Jabsco. We host no manuals or drawings — the manufacturer’s copy is the current one.

Wear parts & part numbers

PartOEM numberAlso fitsNote
Service kit18920-90431,2—31600 and 31620 (a dealer also lists the 31630): valve kit, diaphragm kit, lower housing kit and slide clips — the complete rebuild.
Valve kit18911-70301,3—31600 and 31620; included in the service kit.
Valve kit204070344,5—Check-valve assembly for all 31295 and 31395 -3A models: the housing with the suction and discharge valves.
Diaphragm kit18912-30401,3—31600 and 31620; included in the service kit. Jabsco sells no diaphragm for the 31295/31395 — see tips.
Pump head18914-63401—Complete pumphead for the 40 psi models 31600/31620-0092 and -0094.
Pump head18915-90021,3—Lower housing kit with cam and piston assembly, 31600 and 31620; included in the service kit.
Pump head18910-40401,3—Upper housing, 31600 and 31620 -0092/-0094 (40 psi); the manual lists none for the 25 psi versions.
Pressure switch18916-0040 · 18916-00251,6—40 psi / 25 psi for the 31600 and 31620: -0040 on the -0092/-0094 models, -0025 on the -0292/-0294.
Pressure switch18916-1035 · 18916-1025 · 18916-10404,7,8,9,5,10—Switch kits (switch, cover and switch diaphragm) for the -3A pumps: 35 psi for 31295-3512/-3524, 25 psi for 31395-2512/-2524, 40 psi for 31395-4012/-4024 — in that order.
Port fittings30648-10001—Slide clips that lock the snap-in ports of the 31600 and 31620; also in the service kit.
Port fittings30647-10004,8—Port clips (2 per kit) for the quick-connect ports of all 31295 and 31395 -3A pumps.
Inlet strainer46400-0002 · 46400-0030 · 46400-95008,4—Pumpgard, required ahead of every PAR-MAX inlet: ½ in hose barb / in-line bayonet for the quick-connect ports of the 31295 and 31395 / the same as a 90° version. Also 46400-0003 for ⅜ in and 46400-0000 for ¾ in hose.
Accumulator tank30573-0000 · 30573-00038,4—Optional on every PAR-MAX, smooths the flow and cuts cycling: 1 l / 0.65 l reinforced plastic; 2 gal coated steel 18810-0000. Not for variable-speed pumps.
Rubber mounting feet20717001A4,9—31295 and 31395 (-3A); four rubber feet that damp the pump’s noise.

Numbers checked against the sources below on 12 October 2026. Always confirm against your serial number and exact type before ordering.

Service intervals

TaskInterval
Strainer cleanPumpgard screen and tap aerators: periodically, and at once when the flow drops1
DiaphragmOn condition, no fixed interval: diaphragm, valves and pressure switch when the pump cycles with every tap closed, will not prime, leaks or will not switch off (kits for 31600/31620; for 31295/31395 only switch and valves are sold)1,8
Full serviceSanitise the whole system before winter storage, before using it again and after fitting new parts: 1 ml household bleach per litre of tank, 4 hours, then flush11
WinterisingEvery autumn before frost: drain the tank, open all taps, take the outlet (31600/31620) or both fittings (31295/31395) off the pump and run it briefly until the head is empty1,11
Electrical connectionsOwn fused circuit (fuse per model, see current draw) with a switch within reach; switch the pump off whenever you leave the boat or the tank is empty11,1

From the Jabsco (Xylem) manuals for the 31600/31620 and the 31295/31395 series. Jabsco gives no hour- or calendar-based service interval: the pumps are serviced on condition, the only routine jobs being the strainer, the autumn drain-down and sanitising.

Specifications

Models31295: 3 chambers; current 31295-3512-3A (12 V) and 31295-3524-3A (24 V), replacing 31295-0092/-0094 · 31395: 3 chambers; 31395-2512-3A and 31395-4012-3A (12 V, 25 / 40 psi), 31395-2524-3A and 31395-4024-3A (24 V), replacing 31395-0292/-0092/-0392 and -0294/-0094/-0394 · 31600 and 31620: 4 pistons; -0092 (12 V) and -0094 (24 V) at 40 psi, -0292 and -0294 at 25 psi12,1
TypeMulti-chamber diaphragm pump with permanent-magnet DC motor and built-in pressure switch; 31295/31395 with internal bypass. Intermittent duty: no more than 15 min at a stretch, a thermal cut-out restarts the motor once it has cooled8,11
Flow rateOpen flow: 31295 2 GPM (7.6 l/min) · 31395 3 GPM (11.3 l/min) · 31600 3.5 GPM (13.2 l/min) · 31620 4.3 GPM (16.3 l/min)12
Cut-out pressure31295: 35 psi (2.4 bar) · 31395-25xx: 25 psi (1.7 bar), 31395-40xx: 40 psi (2.8 bar) · 31600/31620 -0092/-0094: cut-in 20 psi, cut-out 40 psi (1.4 / 2.8 bar); -0292/-0294: cut-in 10 psi, cut-out 25 psi (0.7 / 1.8 bar). Max inlet pressure 30 psi (2.1 bar) on 31295/313951,12,8
Voltage12 V or 24 V DC by model; the 12 V 31295/31395 run on 9–13.6 V and come with 305 mm leads, 16 AWG (1.5 mm²). Supply wire for 3 % drop, total run out and back: 12 V 14 AWG (2.5 mm²) to 6 m, 12 AWG (4 mm²) to 9 m, 10 AWG (6 mm²) to 12 m; 24 V 16, 14 and 12 AWG for the same lengths4,11
Current drawMax draw / fuse: 31295-3512-3A 6 A / 10 A · 31295-3524-3A 3 A / 5 A · 31395-2512-3A 5.2 A / 10 A · 31395-4012-3A 6.2 A / 10 A · 31395-2524-3A 2.6 A / 5 A · 31395-4024-3A 3.1 A / 5 A · 31600-0092/-0292 5 A / 10 A · 31600-0094/-0294 3 A / 7 A · 31620-0092/-0292 6 A / 10 A · 31620-0094/-0294 3 A / 7 A. Fuse or breaker not supplied1,12
Ports31295/31395: two ½ in (13 mm) straight hose-barb quick-connect fittings held by port clips · 31600/31620: snap-in ½ in (13 mm) hose barb and ½ in-14 MSPT (QEST) fittings1,8
Suction / discharge headSelf-priming from dry up to 3 m (10 ft); can run dry without damage8
Weight31295/31395: 1.5 kg · 31600: 2.1 kg · 31620: 2.8 kg (31600/31620 shipping weight)1
MaterialGlass-filled polypropylene housing, Santoprene diaphragm, EPDM check valves (31295/31395)8
Operating temperatureFluid and ambient 0–60 °C (32–140 °F); 31295/31395 rated IPX612
Warranty3 years from date of manufacture (31295/31395 manual); 1 year (31600/31620 manual)11,1

Good to know

  • The names are confusing: Xylem’s website calls the 31295 the PAR-MAX 1.9 and the 31395 the PAR-MAX 2.9, the data sheets and the model table call them PAR-MAX 2 and 3, and the 31600 is also a PAR-MAX 3. Order parts by the series number on the pump’s label, never by the name.12
  • Blowing the lines through is not enough because of the pump’s check valves: drain the tank, open the lowest outlet, then take the outlet hose off the pump and run it briefly to empty the head (about a cupful comes out). If you use antifreeze, only the potable-water kind — never automotive antifreeze.1
  • If the pump switches on and off with every tap closed, look for a leak or a dripping tap first, then for a punctured diaphragm or a tired pressure switch. On larger systems an accumulator tank smooths the flow and cuts the cycling.1
  • For the 31295 and 31395 Jabsco sells the switch kit, the check-valve assembly, port clips and feet — but no diaphragm or drive: a failed diaphragm means a new pump. The 31600 and 31620 can be rebuilt completely with service kit 18920-9043.8,1
  • If the pump has to stand vertically, mount it motor-up so a leak cannot drip into the motor, and do not crush the rubber feet when tightening the screws. The free lead at the pressure switch is positive, the black motor wire negative.1
  • Always fit a strainer between tank and pump: it protects the check valves and the pressure switch and is the first thing to clean when the flow drops. Use reinforced 13 mm hose on the inlet and for the main run from the pump; branches not under 10 mm.1

Videos & how-tos

Links to YouTube, nothing embedded. The maker’s own channel comes first; the rest are channels we found clear and correct for this model.

Fitted in

Boats whose builder lists it as standard or optional equipment:

  • Leopard 44 — Jabsco PAR-Max 3.5 GPM (Moorings 4400 list)
  • Leopard 46 — Jabsco PAR-MAX 3 · 3.5 GPM (Builder’s lists of 2006 (‘Par-Max3’) and 2007; the Moorings sheets give a 3.5 GPM pump without make)

On the marketplace

Looking for a part for the Jabsco PAR-MAX pumps? Post a wanted ad in the app — it is free, it sits on the live map, and boaters nearby who have the part aboard can answer.

Got spares you no longer need? List them in a minute. No commission, ever.

Get the app

Sources

  1. xylem.com/siteassets/brand/jabsco/resources/manual/user-guide-par-max-3.pdf
  2. fisheriessupply.com/jabsco-parmax-replacement-parts/18920-9043
  3. fisheriessupply.com/jabsco-parmax-replacement-parts
  4. xylem.com/siteassets/brand/jabsco/resources/technical-brochure/parmax-2-datasheet-31295-3…
  5. xylem.com/siteassets/brand/jabsco/resources/technical-brochure/parmax-3-datasheet-31395-4…
  6. fisheriessupply.com/jabsco-parmax-replacement-parts/18916-0040
  7. xylem.com/siteassets/brand/jabsco/resources/technical-brochure/parmax-2-datasheet-31295-3…
  8. xylem.com/siteassets/brand/jabsco/resources/technical-brochure/parmax-3-datasheet-31395-2…
  9. xylem.com/siteassets/brand/jabsco/resources/technical-brochure/parmax-3-datasheet-31395-2…
  10. xylem.com/siteassets/brand/jabsco/resources/technical-brochure/parmax-3-datasheet-31395-4…
  11. xylem.com/siteassets/brand/jabsco/resources/manual/31295-31395-32600-eries.pdf
  12. xylem.com/siteassets/brand/jabsco/resources/specification/par-max-series-model-number-tab…

Jabsco is a trademark of its owner; boatparts.app is not affiliated with it. Part numbers are quoted for identification only. Spotted an error? Write to mail@boatparts.app.