Expertly Delivered by Qualified Engineers
At The Rainwater Guy, we provide professional specialist installation and commissioning services for rainwater harvesting systems. We focus on the technical installation, setup and commissioning of the rainwater harvesting equipment rather than providing complete groundworks, plumbing and electrical installation.
We have extensive experience working with Graf and other leading rainwater harvesting systems and manufacturers, giving our engineers the knowledge to install and commission a wide range of system types and configurations.
Why Choose a Professional Engineer?
Having a trained professional handle your installation and commissioning ensures:
• Compliance with manufacturer requirements
• Efficient and safe system operation
• Full testing, setup, and calibration of components
• Peace of mind with warranty-backed assurance
• A commissioning certificate for your records
Installation Tailored to Your Requirements
Every rainwater harvesting installation is different. Rather than offering fixed installation packages, we assess the requirements of each project and provide a quotation based on the system type, size, site conditions and level of engineering support required.
Our installation service can be tailored to suit your project, from straightforward installation and commissioning through to more complex projects requiring additional specialist engineering input.
Your quotation will take into account:
- System type and manufacturer
- System size and configuration
- Site and installation requirements
- Components requiring installation and commissioning
- Level of engineering expertise required
- Any additional testing or commissioning requirements
Our Installation Scope
We specialise in the technical installation and commissioning of rainwater harvesting systems and their associated equipment. While groundworkers are often experienced in tank and drainage installation, the setup and commissioning of the rainwater harvesting components requires specialist knowledge.
Our trained engineers provide this specialist expertise, ensuring the system is correctly installed, configured, tested and commissioned for reliable long-term operation.
We do not provide:
- Groundworks, excavation or tank installation
- Plumbing or mains water connections
- Electrical installation or electrical connections
- General building or construction works
These elements should be arranged separately by the customer or main contractor with appropriately qualified trades. We can work alongside your groundworker, plumber and electrician to ensure the rainwater harvesting system is correctly installed and commissioned.
If you require one contractor to manage and complete the entire installation, including groundworks, plumbing and electrical works, we are unable to provide this service.

Already Installed?
Commissioning-Only Service Available
If your system has already been installed, we offer a standalone commissioning service, which includes:
• Compliance check against manufacturer guidelines
• Full system operation testing and fine-tuning
• Issuance of a Commissioning Certificate
Support for Commercial Projects & Housing Developments
All of our installation and commissioning packages can be tailored to suit larger commercial systems and multi-property developments.
Whether you're a commercial client installing a high-capacity rainwater harvesting system, or a housing developer needing multiple systems installed/commissioned across several new builds, we have the capacity and expertise to support your project.
We can coordinate with your site teams to ensure consistent, compliant installation across all properties, helping streamline your handover process and ensure long-term system performance.
Contact Us Today
Whether you’re starting a new install or need professional commissioning for an existing system, we’re here to help.
Get in touch to discuss your needs, view package options, or receive a tailored quote.



