Do You Need Plumbing Adjustments After Installing Solar Panels?

Going solar is an exciting step. You’re cutting energy costs, reducing your carbon footprint, and adding value to your home. But there’s a detail many homeowners don’t think about: how solar might affect the plumbing.

In some homes, the impact is minimal and only requires a quick check. In others, plumbing adjustments may be needed to keep water pressure steady, protect pipes, and ensure your hot water system keeps up with the new setup.

This guide walks you through the plumbing considerations to check after solar installation. By staying on top of them, you’ll avoid unnecessary issues, keep your system running efficiently, and get the best return from your solar investment.

How Solar Panels Can Affect Your Plumbing System

Most people think solar is just about generating electricity. That’s true for standard PV panels, but depending on your setup, solar can also affect how your plumbing works. 

If you’re using solar for water heating, the system connects directly into your existing plumbing. Even if your panels only produce electricity, the installation on your roof can still influence pipes, vents, or drainage.

• Solar water heating: A thermal system preheats water before it enters your regular hot water cylinder.

• Roof plumbing lines: Older homes sometimes have pipes running near or under the roof surface. Adding panels may mean those lines need adjusting or protecting.

• Rain and drainage: Panels change how water runs off your roof. In places like Auckland, where heavy rainfall is common, checking gutters and downpipes after installation is important.

Key takeaway: Installing solar is not just about panels and wiring. It can also affect your plumbing and drainage. Taking a quick look at your layout now can help you avoid bigger problems later.

Check Your Water Pressure

When you add solar panels, and especially if you install a solar water heating system, it is important to make sure your water pressure stays consistent. High pressure can put extra strain on pipes and fixtures. Low pressure can turn a good shower into a weak trickle.

Why Solar Might Affect Pressure

If you have a solar water heater, your plumbing now runs through extra components. This can change how water moves through the system. Narrower piping or relief valves may slightly reduce flow, and even small changes to the plumbing path can affect pressure at your taps or shower.

How to Test and Maintain Water Pressure

1. Use a pressure gauge: Attach it to an outdoor tap or hose connection to get a reading. In many areas, including Auckland, normal residential pressure is around 50–70 psi (pounds per square inch).

2. Check the pressure regulator: If the reading is outside this range, adjust the valve that controls how much pressure enters your home. It is usually located where the main water line comes in.

3. Inspect for leaks: Look closely at any new pipes, joints, or valves connected to the solar setup. Even small cracks or loose fittings can cause drips, floods, or pressure drops.

Keeping water pressure in the right range protects your solar water system and helps extend the life of your entire plumbing network.

Evaluate Your Hot Water System

If your water heater is connected to solar panels or a solar thermal system, you are using the sun to help supply hot water. To keep things running smoothly and safely, check a few key points.

Check Your Water Heater’s Compatibility

• Size and capacity: A small water heater may not cope well if it has to store extra hot water from a solar collector. Make sure your system is large enough to handle the added load.

• Temperature settings: Solar-heated water can get hotter than you expect. Keep the thermostat in a safe range, usually around 120°F (49°C), unless local rules or personal preference say otherwise.

• Relief valve function: Hot water expands quickly under strong sun. Test the temperature and pressure relief valve to confirm it opens when pressure builds and reseals properly afterwards.

Decide If You Need a Booster Heater

In places with mixed weather, like Auckland, solar alone may not keep water hot every day. Adding a booster heater ensures you still get reliable hot water when the sun is weak.

• Solar preheat with electric backup: A common setup that guarantees hot water even after several cloudy days.

• Gas backup: More costly to install, but delivers steady performance if you want extra reliability.

• Integrated systems: Some heaters can combine both sources, with solar preheating the water before a traditional heater finishes the job.

Think about your household’s hot water use, the local climate, and your budget. A small backup heater can make a big difference and save you from cold showers on grey days.

Inspect Your Pipes

Most of us only notice plumbing when something goes wrong. After installing solar panels, it is a good time to give your pipes a quick check. The extra weight on the roof or changes made during installation can sometimes shift or affect existing lines. A quick inspection helps ensure everything is still in good condition.

Look for Signs of Damage or Shifting

1. Loose fittings: Brackets or joints may have been disturbed, leading to small leaks or drips.

2. Corrosion or rust: Older galvanized or iron pipes are more vulnerable when exposed to roof moisture.

3. Bent or pinched lines: Equipment installed above or near plumbing can sometimes squeeze or kink pipes, affecting water flow.

Choose the Right Pipe Materials

If you are upgrading or your installer has suggested new pipes, choose materials that suit your system and climate:

• Copper: Durable and heat-resistant, ideal for hot water but more expensive.

• PEX (cross-linked polyethylene): Flexible, affordable, and easy to re-route.

• PVC (polyvinyl chloride): Commonly used for cold water or drainage, but not recommended for high heat.

In Auckland, where temperatures shift between warm and cool, pipes that handle expansion and contraction well are the safest option. Talk with a plumber about what works best for your budget and solar setup.

Plan Routine Maintenance

A simple maintenance routine is the easiest way to keep your plumbing, solar panels, and hot water system in good shape. You don’t need specialist training—just a quick look around your property every so often.

Start with these simple maintenance tasks to keep your system running efficiently:

• Visual inspections: Once a month, check panels, pipes, and mounting hardware for anything loose, cracked, or discoloured.

• Clear debris: Remove leaves and branches from your roof and gutters to prevent water backups that can damage plumbing and roofing.

• Flush the water heater: Every six months, drain the tank to clear out sediment. This is especially important if solar is preheating water, since higher temperatures can cause more buildup.

Consider Professional Help

Most solar kits are designed for DIY installation, and in many cases you can handle the setup yourself. However, some situations call for outside help. 

If pipes need to be rerouted, if your system affects water pressure, or if you notice leaks around roof penetrations, it is safer to bring in a licensed plumber. They can make sure your plumbing is secure, compliant, and ready to work alongside your solar system.

When to Call a Plumber or Solar Technician

• Complex rerouting: If pipes were moved during installation, they need to be re-secured and insulated correctly.

• Code compliance: Local regulations may apply to water heating and plumbing modifications.

• Detailed inspections: A professional can identify leaks, pressure problems, or fittings that might cause trouble later.

Finding the Right Help

If you’re in New Zealand and your install requires plumbing adjustments, it pays to choose a professional who knows the local conditions. For example, Flowpro Plumbers & Gasfitters is a trusted option if you need a reliable plumber in Hibiscus Coast NZ. Their team can help with pipework, water pressure issues, and drainage checks to keep your system safe and efficient.

Wrapping Up: 5 Plumbing Checks for a Solar-Ready Home

Pairing solar with your home is about more than just panels and wiring. Checking your plumbing helps prevent leaks, pressure issues, and costly surprises.

To recap, remember to:

• Test your water pressure after installation.

• Confirm your water heater is sized and set correctly.

• Inspect older pipes for leaks, rust, or kinks.

• Keep up with simple seasonal maintenance.

• Call a professional if plumbing changes go beyond DIY.

By staying on top of these steps, you’ll protect your plumbing and get the best performance out of your solar investment.

And when it comes to setting up solar the right way, Solar Guys Pro gives you the gear, guidance, and support to make it easier. From DIY kits to expert advice, you’ll have everything you need to keep your home running smoothly on clean energy.