When installing a rainwater tank, choosing the right pump is an important decision. Your choice will impact the performance and efficiency of your rainwater system and the long-term costs and maintenance involved. Two primary options exist: external pumps and submersible pumps. Each has its benefits and drawbacks, and this guide will help you make an informed decision based on your needs.
Choosing the Right Pump for Your Needs
If you're looking for a pump for simple uses like gardening or general water pressure boosting an external pump is the way to go 99% of the time. All our submersible pumps are routed through the Rains to Mains controller installed at the top of the water tank. If you're not planning to connect your pump to your home's mains supply, choosing an external pump can save you significant costs by avoiding purchasing a valve set you won't use.
Space Considerations
One of the key differences between external and submersible pumps is how much space they take up.
- External pumps are installed outside the tank, requiring a dedicated space near the tank for installation. While this allows for easy access, it does mean you will have to consider sheltering the pump from the elements and noise reduction.
- Submersible pumps are placed inside the water tank, making them a great option if space around your tank is limited. They are completely submerged in water, keeping them hidden and protected from external damage or interference.
Cost & Warranty Considerations
Budget is always a consideration when choosing a pump, and there's a notable price difference between these two options:
- External pumps generally offer a wider range of options suited for various applications. For the same amount as a submersible pump, you could opt for a higher-quality European or even Australian-manufactured external pump, which may come with a longer warranty of up to 3 years.
- Submersible pumps are more expensive due to their complex design, so warranties are generally shorter. Our submersible pumps offer a 2-year warranty.
Performance Differences
Another key consideration is performance.
- External pumps come in a wide range of specifications, making it easier to find a pump that meets your exact needs. If you require high water pressure, need to move large volumes of water, or need to supply multiple outlets over a long distance, an external pump is far more likely to meet those demands.
- Submersible pumps typically have lower performance for the same cost and are inherently limited by their form factor. If you need high-pressure output for a large number of outlets, a submersible pump may not be able to achieve the required performance.
Servicing & Maintenance
While pump repairs are becoming less common nowadays, repairing or replacing maintenance parts in many external pump systems is still possible. However, due to its complexity, a failed submersible pump will generally require a complete replacement.
- External pumps are easier to service because they are accessible outside the tank. If repairs or maintenance are needed, you don't have to drain the tank or remove the pump from inside the water supply.
- Submersible pumps are more complicated to access, requiring the pump to be pulled from the tank when servicing is needed. This makes maintenance more cumbersome and sometimes more costly.
Noise Levels & Protection
Noise levels can be a concern for some homeowners, especially if the tank is located near a living area.
- External pumps tend to generate more noise during operation. They should be placed inside a pump cover to reduce sound and protect them from weather exposure to mitigate this.
- Submersible pumps operate quietly as they are submerged in water, naturally muffling any sound. If noise is a priority concern, a submersible pump may be better.
Which Pump is Best for You?
Choosing between an external and a submersible pump ultimately depends on your specific requirements:
- If you prioritise lower cost, a wider range of options, easier servicing, and a longer warranty, an external pump may be the best choice.
- If you have limited space, want a quieter operation, and prefer a more premium, out-of-sight-out-of-mind installation, a submersible pump might suit you better.
Still unsure? Contact our team today for expert advice and a tailored recommendation. We'll help you find the perfect pump for your needs!