By Audrey HayesUpdated November 2026
The envirosun solar hot water system is a solar thermal setup sold under the EnviroSun name, and it heats household water using collectors on your roof and a storage tank. In this guide you will learn how these systems generally work, how to match one to your household’s hot water use, and what to check before installation. Because EnviroSun specifications vary by model, always confirm details against the manufacturer’s installation manual.
How an EnviroSun-Type Solar Hot Water System Works
Solar thermal systems circulate a fluid through collectors mounted in direct sun. The collectors transfer heat into water, which is stored in an insulated tank until you draw from it. Most residential setups use either a closed loop with a heat-transfer fluid and a heat exchanger, or a direct system that circulates potable water. Check which type your EnviroSun model uses, because it determines freeze protection and the components you need.
Shopping for one? See our guide: 6 Best Indirect Solar Hot Water System Options for Homes (2026).
Many homes pair solar heat with a conventional backup heater, either electric or gas. The backup switches on when the stored water falls below your set temperature, so you never run out of hot water on cloudy days.
Step 1: Size the System to Your Household
Start with daily hot water demand. A common planning figure is about 15 to 20 gallons per person per day for showers, dishes and laundry, though your actual use may differ. Multiply that by the number of occupants to get a target storage volume, then compare it with the tank sizes listed for your EnviroSun model. Undersizing leaves you short on cold mornings. Oversizing wastes roof space and can slow heating.
Step 2: Choose and Prepare the Mounting Location
Collectors need unshaded, south-facing exposure in the Northern Hemisphere, and tilt roughly equal to your latitude is a standard starting point. Check for shading from trees and neighboring buildings across the full day and across seasons. Confirm that your roof structure can carry the added weight, and plan routing for pipes from roof to tank so runs are as short as practical.
Step 3: Install and Verify the Components
Work through the installation in this order:
- Mount the storage tank on a level, load-bearing base near the plumbing it serves.
- Fix the collector mounting frame to the roof, flashing every penetration to keep it watertight.
- Install the collectors, then run insulated supply and return lines between roof and tank.
- Fit the circulation pump, controller, temperature sensors and any expansion tank or pressure relief valve the manual requires.
- Connect the backup heater so it activates only when stored water is below setpoint.
- Pressure-test and flush the system, then confirm sensor readings and pump operation.
Tools you will typically need include a drill with masonry and metal bits, pipe cutters, a crimping or soldering kit matched to your piping, a multimeter, a pressure gauge, and a level. Electrical connections for the pump and controller should be made by a licensed electrician where local code requires it.
Step 4: Check Freeze Protection and Commissioning Settings
If you live where temperatures drop below freezing, confirm that your model uses a freeze-protected closed loop or drain-back arrangement. Set the controller’s temperature limits and verify that the collector temperature sensor reads accurately in direct sun. Record initial readings so you can spot performance changes later.
Common Mistakes to Avoid
- Installing collectors in partial shade, which cuts output for hours each day.
- Skipping insulation on exposed lines, leading to heat loss before water reaches the tank.
- Using undersized piping, which restricts flow and reduces the pump’s effectiveness.
- Ignoring the manufacturer’s pressure rating and omitting a relief valve.
- Forgetting to check the backup heater’s setpoint, causing it to run unnecessarily and erase solar savings.
Recommended Gear
- Fluke 117 Electrical Multimeter helps you verify pump and sensor wiring before you power the controller. View on Amazon
- Milwaukee M18 Fuel Hammer Drill handles roof-frame and tank-base anchors in masonry and steel. View on Amazon
- Klein Tools Ratcheting Pipe Cutter gives clean, square cuts on copper and steel supply lines. View on Amazon
Related Reading
If you are still comparing options, start with What's the Best Solar Hot Water System? 3 Top Picks Compared (2026) for a broader view. For roof-specific planning, see Solar Hot Water System on Roof: A Step-by-Step Guide to Planning and Mounting. If you want backup integration details, read Solar Hot Water System With Gas Backup: How to Set It Up Right. Storage choices are covered in Top 5 Solar Thermal Storage Tanks for Home Hot Water Systems.
FAQ
Does the EnviroSun solar hot water system work in cold climates?
It can, provided the model uses freeze protection suited to your winter temperatures. Check the manufacturer’s specifications for minimum operating temperature and follow its freeze-protection guidance.
Do I need a backup heater?
Most homes do, because solar output drops on cloudy days and in winter. A backup heater ensures you have hot water at all times.
Should a professional install it?
Installation involves roof work, plumbing and often electrical connections. Consult a licensed professional, especially for roof penetrations, gas or electric backup wiring, and local permit requirements.
Conclusion
A well-sized, correctly sited envirosun solar hot water system can cover a large share of your household’s hot water needs. Start with an accurate demand estimate, follow the manufacturer’s installation steps, and verify freeze protection and backup settings before you rely on it. Always confirm model-specific details with EnviroSun documentation and a qualified installer.
Related reading
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About Audrey Hayes
Audrey Hayes is part of our editorial team and reviews and edits our solar water heaters guides, checking product details against manufacturer specifications and owner feedback.
