Frequently asked questions

Here’s a handy guide to help you choose from Power type, Capacity and Portable or Installed options.

Portable vs Installed options – which is best for you?

Although the Rainman watermaker was originally designed as a portable system not requiring installation, many of our customers choose to partially or fully install the system in their boat. The variations can range widely, including installation of both the pressure supply unit and reverse osmosis case to installing one or the other of the units.

If you are uncertain whether you wish to have a portable or installed watermaker, the best option is to buy the portable version. You can then run it portable for a while and decide if you are happy with that configuration or wish to install it at a later date. It also gives you more time to determine where you want to install the system. Analogous to buying a pre-owned house, you live in it for a while before deciding what renovations you might require. It is easy to install a portable watermaker, but you do not want to uninstall a permanently mounted system.

Take a look at our comparisons table

Why portable?

The origins of Rainman established our reputation as the “Portable Watermaker” in the blue case. Although many customers will prefer to install their Rainman, many benefits exist for keeping your system portable.

Portable benefits:

  • The system can be operated without an installation process. Ten minutes after receiving the system, you can be making fresh drinking water.
  • If you are a cruiser and a racer, you can easily offload about 2/3 of a crew member weight by putting the watermaker ashore.
  • No extra holes in your hull.
  • If you are space-constrained, you can remove the system to fit more people or gear for short trips.
  • If maintenance is required, you bring the system to a technician rather than bringing a technician to your boat.
  • When you upgrade your boat, you take the system with you. Installing a system in your boat will not add significant value to your boat.
  • You can loan it to a friend.
  • Reduced cost due to avoiding expensive and invasive installation process.
  • You can fill your neighbour’s tanks with the product water extension hose.
  • Moving the system around is easy if you have an RV, live near water, or have another boat.
  • You can easily resell the system if you are no longer getting use out of it.
portable System Types Available

You have maximum flexibility in power sources if you wish to keep your system portable. Any of our three platforms can be used as portable. In order of popularity, these include:

AC powered watermaker

The primary design principle in the AC Rainman is that it must start and run using a Honda 2kVA portable generator. The ubiquity of this generator has helped make it the most popular system in our range. It can also run on a good quality 2kVA inverter. Higher capacity generators and inverters are commonly used as well.

Petrol (gasoline) powered watermaker

An update of the original Rainman, this system can run without any external electricity source. Just add fuel and salt water. We designed this with a Honda GXH50 motor and a simple belt drive system.

12-volt DC powered watermaker

This system was designed with lower power and lower flow rates. Simplicity and low maintenance is retained by utilizing a simple triplex plunger pump. Due to the lower productivity and requirement for a shorter power cord, this system is more commonly installed than kept portable.

Why install?

Rainman built our reputation on inventing and commercializing portable watermakers. However, over the years many of our customers prefer to permanently or semi-permanently install their systems into their boat. There are many reasons for this:

Installed benefits:

  • You can operate the system without the need to pull it out on deck.
  • No hoses thrown over the side of your boat while the system is in use.
  • Less concern of hoses getting kicked out of place while in use.
  • Easier to use while underway.

Read more about the Plumbing Install Kit

How to install your Rainman Watermaker

Installation System Types Available

If you decide to install a Rainman watermaker, you can choose from any of our electric systems. We do not recommend you install our petrol (gasoline) powered watermaker.

Options include:

AC powered watermaker

The primary design principle in the AC Rainman is that it must start and run using a Honda 2kVA portable generator. The ubiquity of this generator has helped make it the most popular system in our range. It can also run on a good quality 2kVA inverter. Higher capacity generators and inverters are commonly used as well.

Petrol (gasoline) powered watermaker

An update of the original Rainman, this system can run without any external electricity source. Just add fuel and salt water. We designed this with a Honda GXH50 motor and a simple belt drive system.

Types of Installation

Both the case and naked systems can be installed and plumbed in various configurations. Below are high level schematics of four possibilities (click on image for larger view).

The core components of the installation are:

  • Dedicated or shared through the hull for intake of seawater.
  • Ability to draw water out of a bucket for flushing or pickling the watermaker. Using our autoflush option means you will rarely, if ever, need the pickling bucket.
  • Control product water flow for testing or filling your tank.
  • Brine waste water goes overboard.

If you plan to fully install your Cased Rainman system, the plumbing kit can be purchased as an option.

Read more about the Plumbing Install Kit

How to install your Rainman Watermaker

Cased vs naked options
The system can be purchased either as the traditional blue case version or in the Naked configuration. The pricing, performance and power consumption are identical between the two options, so your specific requirements control which is best suited for your application.

The option to choose between the cased and naked versions only applies to the Rainman AC (Electric) Watermaker and the Rainman 12 Volt DC Watermaker. The Rainman Petrol (Gasoline) Watermaker is only available for purchase as a cased option.

To see the differences between the cased and naked options for the Rainman AC (Electric) Watermaker or the Rainman 12 Volt DC Watermaker, please take a look at the table that summarizes the differences between the two options on their respective product pages.

AC (Electric) Watermaker – Cased vs Naked Options

Rainman 12 Volt DC Watermaker – Cased vs Naked Options

Price differences

Please note:  The pricing for the cased and naked options that are available for the AC (Electric) Watermaker and the Rainman 12 Volt DC Watermaker, respectively, are the same.

Reverse Osmosis Options

We offer three standard reverse osmosis (RO) membrane options, all of which are designed to be compatible with either the electric or petrol (gasoline) versions of our pressure supply unit. The RO options were designed to suit a wide variety of customers, catering for economy, compact, and high output requirements. We have three standard options that cater to the vast majority of customers, but we can make custom configurations on request. Please contact us for discussion on custom configuration or size.

Many customers ask which RO option suits their needs best. A couple of things to think about include power consumption and physical space requirements. If you can fit the 40″ RO membranes, we recommend either the High Output or Economy system as the most cost effective solutions. However, if you are physically limited on space, then the Compact system is the best option. The pressure supply units will consume the same power regardless of which RO unit is attached, so the High Output RO case is the most energy efficient.
Both the AC (Electric) Water Maker and the Petrol (Gasoline) Water Maker are available in three options for the reverse osmosis (RO) unit, depending on your water requirements, space available, and budget.

Due to the lower flow rate of the 12 Volt DC Water Maker’s PSU, only the single 40″ membrane configuration of the Economy RO unit is supported for this option.

How to use the watermaker
After a few uses, it will take about two minutes to set up your watermaker for use. More detail is available in the operations manual, but the steps are:

  1. Set the systems up. You may choose to leave the systems in a locker and only move the hoses around.
  2. Hook the black high pressure hose from the reverse osmosis case (RO) into the quick connect coupling on the pressure supply unit (PSU).
  3. Put the intake hose into seawater.
  4. Put the green waste brine hose overboard.
  5. Turn the system on.
  6. Slowly pressurize the system to 55 bar (800 psi) using the control valve. Fresh water will begin coming out of the white product water hose.
  7. Let it run for a short period of time, then put it in your tank.
  8. When the tank is full, depressurise the system and put it away.
Maintenance Requirements

While there is limited maintenance on your Rainman watermaker, there are a few things that should be looked after to ensure a long life of your system.

When storing system:

Fresh water flush and pickle the system when storing it for more than a couple days. This may sound complex, but it is an easy five minute process with no specialist knowledge required.

5-50+ hours of use:

  • Change the non-proprietary pre filter after 5-50+ hours of use, depending on cleanliness of the source water.

1-2 years:

  • Change non-proprietary impeller in the lift pump after a year or two, depending on use.
  • Change the high pressure pump oil each 300 hours of use, using SAE-30 weight oil.

5-10 years:

  • Change the non-proprietary sized reverse osmosis membranes after 5-10 years.
  • If your system starts losing performance, the non-proprietary pump seals may eventually require replacing.
Rainman Desalination Warranty

Rainman desalinator pressure supply unit and RO membrane units are guaranteed to be free of manufacturer defects and to perform within the published specifications for a period of two years from the date of shipment to the original purchaser.

In the event of a warranty claim, Rainman Technology will inspect the defective component and repair or replace at our discretion. All shipping charges are the responsibility of the purchaser to and from our office in Sydney, Australia.

The warranty is void if the system was mishandled, abused, or not operated / maintained as directed by the user manual. Consumable items, such as the pre-filter cartridges, lift pump impeller, high-pressure pump oil, high-pressure pump packings, high pressure hose, engine lubricant, or RO membranes are not covered under the terms of this warranty.

The Honda engine within the Rainman pressure supply unit has a three year Honda warranty. The system can be brought to your local Honda dealer for engine warranty issues.

Rainman Technology’s liability under this warranty is limited to repair or replacement of our systems to the original purchaser. Under no circumstances is Rainman Technology liable for consequential damages related to the failure of the system to perform.

IMPORT DUTIES & SALES TAX

For the USA – the price billed on checkout will be the Landed Cost (includes freight, import duty and sales tax),

For all other countries – the price billed on checkout will be the item cost + freight rate only; the recipient will be liable to pay import duty and sales tax (if applicable) in their country.

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