Solar to Heat Pump Hot Water
Solar Hot Water to Heat Pump: Is It Worth Upgrading?
What happens to the roof collectors, booster and old tank — and whether a ground-level heat pump makes more sense for your home.
Replacing solar hot water with a heat pump can simplify the system by moving hot-water collection and storage back to ground level. The conversion depends heavily on whether you have a roof-mounted close-coupled solar system or a split solar system with a ground-level tank, as well as the existing booster, roof access, plumbing and electrical setup.
Does Heat Pump Suit My Solar Home?
Start with the type of solar hot-water system you already have. This makes a major difference to the conversion.
1 What solar hot-water setup do you have?
2 What booster does the solar system use?
3 What matters most?
Guide only. Roof access, collector removal, booster type, plumbing, electrical requirements, tank position, airflow, drainage and household demand need to be checked for the final conversion.
Can You Replace Solar Hot Water With a Heat Pump?
Yes. Both close-coupled and split solar hot-water systems can be replaced with a heat pump. The conversion is usually simpler when the existing solar system already has a ground-level storage tank, while a roof-mounted tank and collector system can involve additional roof access, removal and plumbing work.
Solar Type
A roof-mounted close-coupled system and a split solar system have very different removal and replacement requirements.
Roof Equipment
Old collectors, roof tanks and associated pipework need to be considered as part of the final conversion scope.
Booster Supply
Existing electric or gas boosting can affect what services are already available and what needs to change.
Heat Pump Position
The replacement system needs a suitable ground-level position with airflow, drainage, electrical supply and service access.
First: What Type of Solar Hot-Water System Do You Have?
This is the biggest factor in how straightforward the conversion is. Solar hot water generally falls into two broad installation styles.
Tank & Collectors on the Roof
The storage tank and solar collectors are mounted on the roof. Changing to heat pump moves the storage system to ground level.
Removal can therefore involve roof access, lifting or handling of the old tank and collectors, disconnection of roof pipework and making the former installation area safe and weatherproof.
Collectors on the Roof, Tank on the Ground
The existing ground-level storage position may already provide a practical starting point for the new heat pump.
The old roof collectors and solar circulation pipework still need to be considered, but the tank-side conversion can often be more straightforward.
Why Change From Solar Hot Water to a Heat Pump?
Solar thermal hot water can work very well in the right property, particularly when the collectors, roof orientation and storage system remain in good condition. Heat pumps become attractive when the existing solar system is ageing, roof work is becoming expensive, the household already has rooftop solar PV or a simpler ground-level replacement is preferred.
Keep Hot Water at Ground Level
A heat pump can remove the need for active solar hot-water collection equipment on the roof and place the main working system where it is easier to access.
Use Rooftop Solar PV Instead
Homes with solar electricity can operate a heat pump during daylight hours, using PV generation to contribute to water heating.
Avoid Rebuilding an Ageing Solar-Thermal System
Where an old tank, collectors, pump or roof pipework all require work, changing technology can be worth comparing against rebuilding the existing solar-hot-water setup.
Solar Hot Water vs Heat Pump: Current JR Starting Prices
A new solar-hot-water installation and a heat pump have very different installation requirements. These panels read JR's current advertised starting prices from the two live main-menu collections.
Uses dedicated solar-thermal collectors to heat stored water, with boosting available when solar contribution is insufficient.
Current JR advertised starting price. Final price depends on system type, roof access, collector layout, booster and installation scope.
Uses electricity to transfer heat from the surrounding air into a ground-level storage tank.
Current JR advertised starting price. STC eligibility depends on the exact system and completed installation.
Solar Hot Water vs Heat Pump Hot Water
| Consideration | Solar Hot Water | Heat Pump |
|---|---|---|
| Primary heat source | Solar thermal energy collected on the roof | Heat transferred from surrounding air |
| Roof equipment | Collectors and sometimes the storage tank | No dedicated solar-thermal collectors required |
| Ground-level equipment | Depends on close-coupled or split design | Storage tank / heat-pump system at ground level |
| Solar PV compatibility | Solar thermal operates independently of PV | Can use household solar-generated electricity |
| Weather dependence | Solar contribution changes with available sun | Extracts heat from surrounding air and uses electricity |
| Boosting / backup | Electric or gas boosting may supplement solar | System-specific controls and backup heating vary by model |
| Roof servicing | Roof components may require future access | Main hot-water equipment remains ground level |
| Typical reason to choose | Direct solar-thermal water heating | Ground-level efficiency and PV-friendly electrification |
What Happens to the Old Solar Collectors and Roof Tank?
This should be decided as part of the conversion rather than treated as an afterthought. The correct scope depends on the existing system design, roof condition, access and what equipment is being permanently taken out of service.
Close-Coupled Roof Tank
If the existing storage tank is on the roof, the conversion needs a plan for safely decommissioning and, where included in the scope, removing the old tank and collectors.
Split-System Collectors
A split solar system may already have its storage tank at ground level. The collectors and solar circulation loop can then be dealt with separately from the new heat-pump tank installation.
Roof Penetrations & Pipework
Removing old solar equipment can also involve roof-mounted pipework, brackets and penetrations that need to be considered in the finished scope.
What Happens to the Existing Solar Booster?
Solar hot-water systems commonly use backup heating when solar contribution is not enough. Whether your current system is electrically or gas boosted affects what services are already available at the property.
Existing Electrical Infrastructure May Help
An electrically boosted solar system already has electrical infrastructure associated with hot water.
That does not automatically mean it is suitable for the selected heat pump. Circuit arrangement, protection, connection type and appliance requirements still need to be checked.
Gas Needs to Be Dealt With
If the solar system uses a gas booster, changing to heat pump removes gas from the hot-water system.
The old booster connection needs to be dealt with appropriately, while suitable electrical power needs to be available for the new heat pump.
Solar Hot Water and Solar PV Are Not the Same Thing
An older solar hot-water system uses dedicated collectors to heat water directly. Rooftop solar PV produces electricity. If your home already has solar PV, a heat pump can allow that electricity to contribute to water heating without requiring a separate solar-thermal collector system.
Solar Thermal
Dedicated roof collectors absorb solar energy for the hot-water system itself.
Solar PV + Heat Pump
Solar panels generate household electricity, and a heat pump can be scheduled to consume some of that electricity during the day.
Hot Water Stores the Result
The heat-pump tank stores heated water so daytime energy can contribute to hot water used later.
What Changes During a Solar-to-Heat-Pump Conversion?
Existing Solar System Is Decommissioned
The old tank, collectors, circulation components and booster arrangement are identified and taken out of service as required by the agreed scope.
Roof Scope Is Confirmed
Where roof equipment is being removed, access, lifting, brackets, pipework and the finished roof condition are considered.
Ground Position Is Selected
The new heat pump needs stable support, airflow, drainage, electrical access and enough room for future service.
Plumbing Is Adapted
Existing water services are reused or redirected where appropriate for the new heat-pump position.
Electrical Work Is Completed
The electrical connection is matched to the exact heat pump selected rather than assuming the old booster circuit is automatically suitable.
Heat Pump Is Commissioned
The new tank is filled and the system is tested, configured and checked for normal operation.
When Staying With Solar Hot Water Can Still Make Sense
A heat pump is not automatically better simply because the existing solar system is older. A replacement solar-hot-water system can still be a practical choice for a suitable property.
Excellent Solar-Thermal Roof Position
A property with strong solar exposure and a practical collector location may continue to suit solar thermal very well.
Existing Solar Infrastructure Is Reusable
Where parts of the existing installation remain suitable, the complete replacement scope can differ significantly from starting again.
Heat-Pump Location Is Poor
Limited ground space, difficult airflow, noise-sensitive positions or unsuitable drainage can make a heat-pump conversion less straightforward.
How a Solar-to-Heat-Pump Replacement Works
Identify the Existing Solar System
Confirm whether it is close-coupled or split, the tank location, collector arrangement and booster type.
Choose the Heat Pump
Compare household sizing, recovery, controls, noise, electrical requirements, warranty and price.
Confirm Roof & Removal Scope
Determine what old collectors, roof tank, brackets and solar pipework are included in the decommissioning or removal work.
Install the Heat Pump
The new ground-level system, plumbing, valves, drainage and electrical connection are completed.
Commission & Test
The heat pump is filled, tested and configured for normal household use.
Complete STC Requirements
Where the new heat pump is eligible, the applicable documentation and STC assignment pathway are completed.
Solar Hot Water to Heat Pump FAQs
Can I replace solar hot water with a heat pump?
Yes. Both close-coupled roof-mounted solar hot water and split solar systems can be replaced with a heat pump. The conversion scope depends on the old tank location, collector arrangement, booster type and condition of the existing installation.
Is it worth replacing solar hot water with a heat pump?
It can be worth comparing when the existing solar system is ageing, roof repairs or collector replacement are becoming expensive, a simpler ground-level system is preferred or the home already has rooftop solar PV that can contribute electricity to heat-pump operation.
What happens to the old solar panels or collectors?
The old solar-thermal equipment needs to be dealt with as part of the agreed conversion scope. What is removed depends on whether the system is close-coupled or split, roof access, the existing installation and whether the collectors and related roof equipment are being permanently removed.
What happens to a solar hot-water tank mounted on the roof?
A close-coupled roof-mounted storage tank needs to be decommissioned when the system is replaced. If removal is included, the weight, roof pitch, access and associated collectors and pipework all affect the removal scope.
Is replacing split solar with heat pump easier?
It can be more straightforward because a split solar system already has a ground-level storage tank and water services in that area. The roof collectors, circulation pipework, booster and exact heat-pump requirements still need to be considered.
Can the heat pump use the same position as my split-solar tank?
Often, where the position provides suitable airflow, drainage, electrical access, manufacturer clearances and service access. The final position still needs to suit the exact heat pump selected.
Can a heat pump use my existing solar booster electrical circuit?
Potentially, but it should not be assumed. An existing electric booster means hot-water electrical infrastructure is already present, but the circuit, protection and connection still need to suit the exact heat pump.
What if my solar hot water has a gas booster?
Replacing the solar system with a heat pump removes the gas booster from hot-water operation. The gas connection needs to be appropriately dealt with, while suitable electrical supply is required for the new heat pump.
Is rooftop solar PV useful with a heat pump?
It can be. Many heat pumps can be scheduled to operate during daylight hours, allowing rooftop solar PV generation to contribute to water heating where household usage and the selected system suit that operating strategy.
Is solar PV plus heat pump the same as solar hot water?
No. Solar hot water uses dedicated solar-thermal collectors to transfer solar heat into water. Solar PV generates electricity, which can then power household appliances including a heat pump.
Can I get STCs when replacing solar hot water with a heat pump?
An eligible new air-source heat pump may qualify when the exact listed model and completed installation meet the applicable STC requirements. Eligibility relates to the new system and completed installation.
Does replacing solar with heat pump mean I need roof work?
It can, particularly with close-coupled systems or where collectors are being removed. The required work depends on roof access, system type, brackets, pipework and what equipment forms part of the agreed removal scope.
Ready to Compare Solar Hot Water Against Heat Pump?
Start with the type of solar system already installed, then compare the roof-removal scope, ground-level installation, heat-pump sizing, electrical requirements and final installed price. If solar thermal still suits the property, compare JR's current solar hot-water range instead.