UniMaxx™ Solar Pump Station Replacement Pump


The Star 30 is the definitive replacement pump for SunMaxx’s UniMaxx™ solar pump stations. Built with durable and efficient components, this pump ensures smooth and reliable operation within your solar hot water system. It is designed to handle a broad temperature range and is equipped with an IP 44 protection class, ensuring robustness in various operating conditions. Its efficient power consumption and easy installation procedures make it a cost-effective and time-saving solution for solar hot water installations.

SKU: UniMaxx-Plus-SC-S30-R Category:

How to order? 

  • Order online or contact sales team directly
  • 24-hour online order confirmation
  • SunMaxx Solar™: solar hot water equipment manufacturer
  • Availability and production lead times subject to production queue

Direct-from-Manufacturer Pricing

Experience the value and benefits of our manufacturer-direct pricing on all online listings. For wholesale and distribution inquiries, we encourage you to reach out to our office to receive a tailored offer that meets your needs.

Looking to connect with our office? Give us a call at 1-877-786-6299, and we'll be happy to assist you!


Solar Pump Station Replacement Pump

SunMaxx Solar offers pre-packaged solar hot water heating systems for both the do-it-yourself customer and the professional installer. Each system includes the primary components required when installing a solar hot water heating system. It is our goal to keep our product cost low in order to ensure that we are making renewable energy products more affordable to the community.

The Star 30 is the standard replacement pump for SunMaxx’s UniMaxx™ solar pump stations. If your existing pump fails, this is the definitive replacement to ensure compatibility and proper functioning with your SunMaxx solar hot water system.


  • Replacement pump suitable for solar systems
  • Threaded connection: 1 1/2IN
  • Model: Wilo Star S30 U25
  • Permissible temperature range: -14°F to 230°F
  • Mains connection: 115/120 V, 60 Hz
  • Protection class: IP 44
  • Max. operating pressure: 145 PSI
  • Power consumption: 1/10 HP
  • Max. Amperage: 1.08A
  • Pump Materials: Pump housing – Grey cast-iron, Impeller – Polypropylene, Shaft – Stainless steel insulation – EPP, Fittings – Brass, Seals – Viton/teflon, Bearing – Carbon

Product Highlights

The Star 30 is a highly reliable, durable and efficient replacement pump, designed specifically for SunMaxx’s UniMaxx™ solar pump stations. It promises optimum performance even under demanding conditions.

Choose the Star 30 as your standard replacement pump for the SunMaxx UniMaxx™ solar pump stations. This product will guarantee optimal performance, reducing maintenance time and costs for your solar hot water system.

Features & Benefits

  • 3 different speeds options available
  • Two pumps may be used when additional head pressure is needed
  • Ideal for small commercial and large residential solar hot water and heating systems
  • UniMaxx Pump Skids are built with Wilo Star S30 U25 pumps
  • flows up to 30 GPM
  • Larger, custom pump systems are available upon request

Technical Details


  • Model: Wilo Star S30 U25
  • Permissible temperature range: -14°F to 230°F
  • Mains connection: 115/120 V, 60 Hz
  • Protection class: IP 44
  • Threaded connection: 1 1/2”
  • Max. operating pressure: 145 PSI
  • Power consumption: 1/10 HP
  • Max. Amperage: 1.08A

Pump Materials:

  • Pump housing: Grey cast-iron
  • Impeller: Polypropylene
  • Shaft: Stainless steel insulation – EPP
  • Seals: Viton/teflon
  • Bearing: Carbon

Below, the pressure drop characteristic of UNIMAXX-PLUS-SC-S30-R solar pump, which is the heart of the solar hot water pumping system, is presented:

SunMaxx’s Pump Stations are an all in one solar hot water component featuring a circulator pump, a digital controller and valves engineered to keep your system circulating the solar heat transfer fluid through the collectors and into the storage tank.

SunMaxx will size a pump station specific to your needs. No need to do the math!!!

Our pump station’s fill valve has GHT hose threads on the outside. You can easily make an adaptor using the following three fittings, which can be purchased at your local hardware store or plumbing supply.

  • Schrader valve x ¼” male NPT
  • Reducing Bushing, ½” NPT Male x ¼” NPT Female
  • Hose fitting, ½” NPT male x ¾” swivel GHT female

Use Teflon tape on the NPT threads of the Schrader valve and bushing in constructing the adaptor. When attaching the adaptor to the pump station, be sure to use two tools: one to hold the fill valve in place, and one to tighten the adaptor. That way, you won’t create leaks in the pump station itself while testing.

Take a deep breath and let all your air out… of your Solar thermal system One of the biggest issues with a successful commissioning is air removal. Any time you spend with this detail will be time well spent. Air pockets become entrained within your HTF and like to find places to hide. Air pockets can form between your HTF and the inner wall of piping (especially with flexible piping) and can only be removed through persistence and time. Here are a few things you can do to help this process. First, be sure that your air purger is located on the high and hot side of your collector series. The hotter the fluid the less the ability for dissolved gasses to stay in solution and the higher the air vent, the more likely you will effectively remove trapped air that, due to its buoyancy, will rise to the top. Once you feel most of the air has been removed this way, you can shut that air eliminator off or remove it all together. If you install a Titan Power Plus collector, you will have a manual air bleeder permanently installed in your line set connections. If you install a ThermoPower collector, you will include an air vent that should be isolated and de-commissioned at this point. Now, down to the pump station. The UniMaxx pump stations have an integral air eliminator with a scoop that will allow entrained air to collect and be bled off manually by opening the valve up to a full turn until HTF comes out. This can be done each day for the first few days or periodically checked. Smaller systems will take much less time removing the air. Another way of enabling the removal of air is to run the pump at maximum speed during commissioning, this will help to break the friction that holds the bubbles to the inner wall thus forcing the bubble through and out. After words, you should adjust your pump speed accordingly. If air persists in your system, it will inevitably find its way to the suction side of your pump and cause cavitation and eventual pump failure. If your pump appears to be not pumping, it is likely that although it is receiving 115v, it cannot pump because of air pockets. Simply unplug your pump and manual override and give it a few minutes. Air will work its way out, pump can run and then you need to go back to the air purging steps. Please view our SunMaxx technical manual (linked) for further instruction in effective system commissioning.

Solar Pump Stations

UniMaxx Compression Connectors


Replacement Parts

System Charge Kit

  • Solar Hot Water System Charging Kit

    The Solar Hot Water System Charge Kit from SunMaxx Solar™ is an all-in-one solution designed for efficiently charging your solar collector system with glycol solution. This comprehensive kit includes a…

How to Order:

If you are confident with your solar hot water heating requirements you can place your order online by clicking on the add to cart button which is located above. All orders are reviewed by our solar hot water heating department and the customers are contacted in order to ensure that you have ordered the correct merchandise for your application. In the event you have any questions our sales staff are available from 8:30AM to 5:30PM EST.

Silicon Solar Inc ships products internationally please ask your sales representative for a shipping rate to your destination.

Need Assistance?
If you have questions need help or simply feel uncomfortable placing your order online feel free to contact the product representative at 1-800-786-0329.

Why SunMaxx Solar

Investing in a complete solar hot water kit from a single manufacturer is essential for ensuring the longevity and efficiency of your solar hot water system. A streamlined approach to sourcing components simplifies the process of installation, maintenance, and servicing.

By choosing a single manufacturer for your solar hot water kit, you can benefit from comprehensive documentation for service and maintenance. This approach helps prevent issues arising from improperly installed or maintained systems. Studies show that over 60% of solar hot water systems fail due to incorrect installation or lack of proper maintenance.

Purchasing a complete kit from one manufacturer guarantees compatibility between components and streamlined support from the provider. This ensures that you have access to knowledgeable experts who can address any concerns or questions related to your specific system. Furthermore, a single manufacturer can provide a unified warranty, eliminating the need to deal with multiple companies in case of any issues.

In summary, investing in a complete solar hot water kit from a single manufacturer is a wise decision for homeowners and businesses alike. It ensures smooth installation, proper maintenance, and reliable long-term performance, maximizing the return on your investment and providing a sustainable hot water solution.