Do you already have an electric geyser installed in your home or business? You may not need to replace your entire hot water system to start benefiting from solar energy.

GreaseFlow Solar Water Heating specialises in solar geyser retrofitting — helping homeowners and businesses upgrade suitable existing hot water systems to use the power of the sun.

A solar retrofit can allow you to use solar energy to heat your water while retaining parts of your existing installation where suitable. This can be an excellent option for properties that already have a conventional electric geyser and want to reduce their reliance on electricity for water heating.

Our team assesses your existing geyser, roof layout, plumbing and hot water requirements to determine the most suitable retrofit solution for your property.

The basics

What is a solar geyser retrofit?

A solar geyser retrofit is the process of modifying a suitable existing hot water system to incorporate solar water heating. Instead of installing a completely new hot water system, we assess whether your existing geyser can be integrated with a solar collector and the necessary connecting pipework and controls.

The solar collector is installed in a suitable position, usually on the roof, where it receives sunlight and transfers heat to the water in the system. Depending on the type of installation, the system may use natural circulation or a pump to move water between the geyser and the solar collector.

Your existing electric heating element may also be retained as a backup, provided the geyser and installation are compatible with the proposed retrofit. This means you can benefit from solar-heated water while still having access to electrical heating when solar energy is insufficient.

How it works

From sunlight to hot water

A solar retrofit system uses sunlight to help heat the water you use every day.

Solar collector installation

A solar collector, such as a flat-panel collector, is installed in a suitable location with good exposure to sunlight. The collector absorbs solar energy and transfers the heat to the water or heat-transfer fluid, depending on the system design.
Heat transfer to your geyser

The collected heat is transferred to the water stored in your geyser. Depending on the system design, this happens through natural circulation or a pump-assisted circulation system.
Hot water for your property

As the water heats up, less electrical energy may be needed to bring it to the desired temperature. The amount of electricity saved depends on sunlight, hot water consumption, system design and the performance of the existing installation.
Electrical backup when needed

During cloudy weather, cold periods or times of high hot water demand, an electric heating element may be used to supplement solar heating if the existing geyser and controls are suitable.

The result is a hot water system that can use solar energy whenever conditions allow.

Suitability

Can my existing electric geyser be converted to solar?

In many cases, an existing electric geyser can be incorporated into a solar water heating system. However, not every geyser or installation is suitable for retrofitting. Before recommending a solution, we assess the condition and specifications of your existing geyser, its position, available roof space and the plumbing configuration.

Geyser condition

The tank must be in suitable condition and compatible with the proposed system.

Geyser position

The location of your existing geyser influences the type of solar system that can be installed.

Roof space

The roof must provide a suitable location for the solar collector, with appropriate sunlight exposure and structural support.

Pipework

Existing plumbing may need modification or additional insulated pipes to connect the collector to the geyser.

System design

The installation may require natural circulation, a circulation pump or other components depending on the layout.

Backup heating

We check whether the existing electrical element and controls can be retained or need modification.

If your current geyser cannot be safely or efficiently incorporated into a solar system, we can recommend an alternative installation.

System types

Types of solar retrofit systems

Different properties require different solar configurations. The correct choice depends on the position of your existing geyser and the layout of your roof.

Pump-assisted solar retrofit

A pump-assisted system is often suitable when the existing geyser is located inside the roof or in another position that is lower than the solar collector. The system uses a circulation pump and suitable controls to move water or heat-transfer fluid between the collector and the geyser.

Useful when natural circulation is not practical

Thermosyphon solar retrofit

A thermosyphon system uses natural circulation rather than an electrically powered circulation pump. It relies on the movement of heated and cooler water, so the relative positions of the geyser and solar collector are critical.

Geyser must sit above the collector

Alternative system configurations

Some properties may benefit from a new solar geyser or a purpose-designed split system rather than modifying the existing geyser. We assess the property and explain the available options before recommending the most appropriate solution.

The right answer isn't always a retrofit

Important: The system configuration is determined by the actual site conditions, equipment compatibility and installation requirements.

Benefits

Benefits of solar geyser retrofitting

Reduce electricity consumption. Water heating can account for a significant portion of a property's electricity use. By using solar energy to heat water, a suitable retrofit system can reduce the amount of electricity required for hot water. Actual savings vary with usage, weather, tariffs and system performance.

Make use of your existing equipment. Where the existing geyser is suitable, retrofitting may allow you to retain part of your current installation rather than replace everything. This can make retrofitting an attractive option for properties looking to upgrade their hot water system.

Use renewable energy. Solar water heating uses energy from the sun, helping reduce dependence on conventional electricity for water heating.

Maintain hot water availability. Where a compatible electrical backup is retained, you can continue heating water when solar energy is insufficient.

A solution tailored to your property. Every property is different. We assess your existing installation and recommend a solution based on your geyser position, roof layout and hot water needs.

Retrofit vs new install

Solar retrofit vs installing a new solar geyser

Both options can provide solar-heated water, but the right choice depends on your existing equipment and budget.

Solar retrofit

A retrofit incorporates a suitable existing geyser into a solar water heating system. It may be appropriate when the tank is in good condition and compatible with the proposed design.

Often the lower-cost route where the tank is serviceable.

New solar geyser installation

A new installation uses equipment selected specifically for the solar system. This may be the better option when the existing geyser is old, damaged, unsuitable or nearing the end of its useful life.

Often the better long-term choice where the tank is not suitable.

At GreaseFlow Solar, we help you compare the options so you can make an informed decision based on suitability, expected performance and overall installation costs.

Honest answer

Is solar retrofitting worth it?

A solar retrofit can be a worthwhile investment if your existing geyser is suitable, your property has adequate solar exposure and your hot water consumption makes good use of the energy collected.

However, the most affordable initial installation is not always the best long-term option. An older geyser that requires substantial modifications may be more expensive to retrofit than to replace with a purpose-designed system.

That is why we recommend an assessment before making a decision. GreaseFlow Solar can evaluate your existing installation and explain whether a retrofit, a new solar geyser or a heat pump is likely to be the most suitable option for your property.

Not sure what to choose? We'll compare retrofit, new solar, and heat pump options for your property in one assessment.

Book an Assessment

Why GreaseFlow

Why choose GreaseFlow Solar?

At GreaseFlow Solar Water Heating, we focus on practical hot water solutions designed around your property's needs. Our goal is to help you make the most of your existing hot water installation wherever practical, while ensuring that safety, reliability and system compatibility remain priorities.

Professional assessments. We inspect your existing installation before recommending a retrofit.
Tailored solutions. We consider the layout of your property and the condition of your current equipment.
Quality installations. We aim to deliver reliable, properly configured solar water heating systems.
Repairs and maintenance. We can help you maintain your hot water system and identify problems that may affect its performance.
Solar and heat pump expertise. We can help you compare solar water heating with alternative energy-efficient hot water solutions.
Cape Town service. We assist homeowners and businesses across Cape Town with solar water heating solutions.

Common questions

Solar retrofit FAQs

Can any electric geyser be converted to solar?

Not every geyser is suitable. The tank must be in good condition, compatible with the proposed solar system and positioned so the installation can work correctly. We assess the geyser, roof space, plumbing and controls before recommending a retrofit.

Will I still have hot water on cloudy days?

Where a compatible electrical backup element is retained, you can continue heating water when solar energy is insufficient. The amount of backup heating required depends on weather, usage and system design.

How long does a solar geyser retrofit take?

Most residential retrofits are completed in a day, but the timeframe depends on the system design, roof access, pipework modifications and whether additional controls or a circulation pump are required.

Is a retrofit cheaper than a new solar geyser?

Often, but not always. If the existing geyser is old, damaged or requires extensive modification, a new purpose-designed system may be the better long-term choice. We compare both options during the assessment.

Will a retrofit reduce my electricity bill?

A suitable retrofit can reduce the electricity used for water heating, but actual savings depend on household usage, weather, tariffs, system design and how often the electrical backup element runs.

Do I need a pump for a solar retrofit?

It depends on the position of the geyser relative to the collector. Thermosyphon systems rely on natural circulation and require the geyser to be positioned above the collector. Pump-assisted systems are used where natural circulation is not practical.

See all FAQs →

Request an assessment

Book your solar retrofit assessment

Ready to upgrade your existing geyser? You may already have the foundation for a more energy-efficient hot water system. Let GreaseFlow Solar assess your existing geyser and help you determine whether solar retrofitting is the right solution for your home or business.

Request a solar retrofit assessment

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Call: 063 062 2817 · 021 557 4865
Email: info@greaseflowsolar.co.za
Hours: Mon–Fri 07:30–17:00 · Sat 08:00–12:00

What we'll ask

During the assessment, we'll look at the geyser condition, position, roof space, plumbing and your hot water needs — so we can recommend the right retrofit configuration for your property.

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