A modern marine pressurised water system is simple, quiet, easy to maintain and provides hot or cold water at the turn of a tap. It is also versatile enough to provide a full flow or a trickle, depending on requirements.


Diaphragm pumps provide a quiet smooth flow of water with reasonable pressure and are suitable for boats up to 20m (65ft) – simply choose a model suitable for the number of outlets on your boat.

Most systems benefit from an accumulator tank to absorb pressure fluctuations and vibrations (which shorten pump life) and to give better control of hot water systems.   Whale Fresh ICLink to our online shopping site


A new alternative to regular water pressure systems is to fit a Sensor Controlled Pump where motor speed is electronically regulated to maintain steady flow and constant pressure eliminating the need for standard pressure switch control or accumulator tank.

maxi-system-3_5-2-12-volt-cw299-1867-pHow big a pump does my system need?  

Flow rates are given for each pump, with an indication of the number of outlets it can service.

For example:

1 (hot or cold) TAP = 1 outlet
1 (hot and cold) MIXER = 2 outlets

A Par-Max 4 shows that it can service “up to 6 outlets”. This means that you could install either, 3 pairs of taps or 1 galley mixer tap, 1 shower mixer tap and 1 pair of taps.


Fitted close to the pump outlet, the Accumulator Tank acts as a pressure buffer. It will absorb flow from the pump when demand is low and smooth the flow and pressure at taps and showers. With a pump controlled by a pressure switch, the accumulator tank:

  1. Avoids the need for the pump to start immediately each time an outlet is opened.   Accumulator Tank
  2. Prevents rapid on-off cycling of the pump.
  3. Extends pump life, reduces battery drain.

An Expansion Tank is the same piece of equipment, but fitted next to the calorifier to absorb the increase in volume of the stored water as it heats up.

In a system that includes a calorifier, the stored water will expand as it heats up, and hot water will find its way back into the cold water line. To avoid this, the preferred method is to fit a non-return valve and a separate expansion tank. An accumulator tank can also function as an expansion tank, but it is recommended that you fit a separate expansion tank.

Without NRV With NRV
Without Non-Return Valve With Non-Return Valve

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Another good reason to fit and Expansion Tank

Unless there is room for expansion, hot water will escape from the calorifier’s safety valve every time the water is heated. Hot water will be wasted and evaporation will lead to a build-up of scale in the safety valve eventually stopping it from closing fully.

For more information on calorifiers and hot water components please click here.



Wash Down Pump 2

Too much pressure can damage paintwork and other surfaces: too little pressure won’t shift the dirt. Jabsco pressure controlled deck wash pumps generate a vigorous jet of water to wash away mud and slime without damage to the surface underneath. The pump starts and stops automatically at a touch of the trigger, giving you full control over the flow and direction of the jet.

These pump kits come with a pressure controlled pump, strainer, pressure nozzle and port fittings.  Link to our online shopping site






Ballast Puppy

The Ballast Puppy pump from Jabsco has been specifically designed to fill or empty a ballast tank at the rate of 40 litres per minute. Available in 12v with ½” BSP female ports.

The pump comes supplied with a switch for both emptying and filling and has built in run dry protection. The pump has a bronze body and stainless steel shaft.  Link to our online shopping site






Circulation Pump

Quiet, efficient circulation – all day every day!

Pumps for these duties run continuously. They need to be quiet and efficient, with minimal drain on the battery. The seal life of a conventional centrifugal pump is limited. This limitation is overcome in JABSCO’s 59500-series pumps, which have a seal-less magnetic drive.

Suitable for hot water systems and with up to 30,000 hours life expectancy these pumps are made for the job. They are not self priming and require flooding before they will circulate. These pumps are not suitable for seawater.   Link to our online shopping site




These pumps are flexible impeller pumps. The smaller pumps in the range are DC and the larger ones are AC.

 Utility 80   Maxi Puppy 3000

The main benefits of flexible impeller pumps are:

  • They will self-prime rapidly from dry
  • Can handle moderate amounts of suspended matter
  • Maintain their flow rate against discharge heads of several metres
  • Can run dry for short periods of time
  • Bronze pump bodies with stainless steel shafts
  • Fully serviceable
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Amazon Warrior

Manual pumps are usually found in boats to pump out the bilges. Bilges can fill from rain, wave splash, deck wash, hull leakage and spillage. When the bilge is pumped out regularly, the flow rate is not usually critical. The pump needs to be efficient, reliable and easy to use.

Manual pumps are simple, reliable and inexpensive. The larger models may surprise you with their pumping power – and yours! A manual pump may be all you need. Or in an emergency it could be all you’ve got. Think carefully before you decide to do without a manual pump, whatever other types of pump you may have on board.

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Bige Strainer

Two good reasons to fit a strainer in the inlet line of your bilge pump:

  1. The cleaner the water that enters the bilge pump, the more efficiently the pump will work, the less attention it will need and the longer it will last.
  2. Floating and suspended solid matter is drawn towards the inlet pipe when the pump is working. A strainer increases the inlet area and helps prevent choking.

Flexible impeller pumps are renowned for their solids-handling ability, but no pump can work efficiently if its inlet line is chiked.

Whether your pump is manual, electric or engine driven, fit a strainer of ample size, inspect it regularly and clean it when necessary.

Strum box bilge strainers are available for 19mm (3/4”), 25mm (1”) and 38mm (1 ½”) sized pipework.   Link to our online shopping site

Good Pumping Practice

Use pipes of internal diameter at least as large as the nominal bore of the pump ports.

Fit an adequately sized suction strainer to protect the pump from debris. Make sure that it is accessible, and remember to inspect periodically.

Install electric self-priming pumps as low as possible, consistent with a dry, ventilated and accessible location.

Keep suction pipework as short and straight as possible. Use reinforced hose that will not deform or collapse under suction conditions. Check that all connections are airtight.