Registering Residential HPWHs for STCs, VEECs and ESCs: The Five Step Guide

Three schemes pay for residential heat pump water heating in Australia. The Small-scale Renewable Energy Scheme (SRES) runs nationally through the Clean Energy Regulator and issues STCs. The Victorian Energy Upgrades (VEU) program runs through the Essential Services Commission and issues VEECs. The NSW Energy Savings Scheme (ESS) runs through IPART and issues ESCs. All three are deemed schemes: a product is tested once, modelled once, registered once, and every installation of that registered product then creates certificates.

Registration is per product, and the product is the whole system. The heat pump, the condenser arrangement, the tank, the sensor position, the booster element and the control settings all sit inside what gets registered. Two products built around the same heat pump can earn very different certificate counts.

One evidence base serves all three schemes, but not one model run. SRES uses AS/NZS 4234:2008, and VEU and ESS use AS/NZS 4234:2021, so the same product is simulated twice against different climate files and reference assumptions.

This guide sets out the path from a product idea to a listing on all three registers in five steps.

The five step protocol

Steps 1 to 3 run in sequence, because each one needs the output of the one before it. Step 4 runs alongside steps 2 and 3, and it is usually the step that decides whether the product launches on time.

#	Step	Who does it	Typical duration
1	Design	You, with preliminary modelling if useful	Days to weeks, depending on how settled the range is
2	Test	An accredited test laboratory	The longest lead item. Around 30 working days on the bench once booked, and booking is the slow part
3	Model	EnergyAE	About 2 weeks for all three schemes, once documents are complete
4	Certify	An Accredited Certification Body and electrical safety bodies, arranged by you	Runs in parallel. Electrical safety is the usual holdup
5	Register	EnergyAE prepares and lodges, the regulators assess	CER runs three rounds a year. VEU 6 to 8 weeks, ESS 6 to 10 weeks

What the three schemes pay for

The schemes are administered separately, use different equations, publish different climate zones and even round differently. They draw on the same test evidence, which is why the three applications are prepared together rather than one at a time.

	SRES (national)	VEU (Victoria)	ESS (New South Wales)
Administrator	Clean Energy Regulator	Essential Services Commission	IPART
Certificate	STC	VEEC	ESC
Activities	Register of Solar Water Heaters and Air Source Heat Pumps	Activity 1D (replacing electric), Activity 3C (replacing gas)	HEER D17 (replacing electric), HEER D19 (replacing gas)
AS/NZS 4234 edition	2008	2021	2021
Climate zones published	1 to 5	4 (Melbourne and most of Victoria), 5 (alpine and north-east Victoria)	3 (Sydney and coastal NSW), 5 (tablelands and alpine areas)
Insulated storage limit	Under 425 L	700 L or less	700 L or less
Certificate basis	1 STC per MWh saved, deemed to 31 December 2030	1 VEEC per tonne of CO2-e abated over the upgrade lifetime	1 ESC per MWh saved over a 12 year deemed life
Rounding	Round down	Nearest whole certificate	Round down
Lodgement	CER portal, three application rounds a year	VEU Registry, any time	TESSA, any time

What registered products earn

These are real figures, computed from the modelling outputs every listed product has published: 1,170 STC listings, 425 VEU listings and 446 ESS listings on the public registers as at September 2026. All cover a medium household in the most populous zone of each scheme.

Scheme and activity	Zone	Median across the register	Spread across the register
SRES STCs, installed in 2026	3	15	6 to 24
VEU VEECs, Activity 1D, replacing electric	4	9	8 to 10
VEU VEECs, Activity 3C, replacing gas	4	8	6 to 10
ESS ESCs, HEER D17, replacing electric, metropolitan	3	27	23 to 30
ESS ESCs, HEER D19, replacing gas, metropolitan	3	12	9 to 16

At indicative reference prices of $40 per STC, $85 per VEEC and $30 per ESC, the median product returns roughly $600 in STCs, $765 in VEECs or $810 in ESCs per installation. Certificate prices trade on spot markets and move, so treat those as the start of a business case rather than a quote. STCs and VEECs can both be created for the same Victorian installation, and state consumer rebates stack on top of the certificate schemes again.

Two things in that table are worth reading carefully. The STC spread is wide, a factor of four between the lowest and highest listings, and efficiency moves the count directly. The VEEC spread is not: Activity 1D subtracts a scaled energy term from a fixed abatement constant, so a substantially more efficient product earns about one more VEEC. Where a design decision is being justified on certificate return, it matters a great deal which scheme is paying.

STC entitlements also fall each year. The deeming period shortens toward the scheme’s end on 31 December 2030, so a product earns fewer STCs for a 2027 installation than for a 2026 one. VEEC and ESC counts have no equivalent annual step-down.

For a figure against a specific product, the residential certificate boards show what every listed model currently earns in each scheme and zone.

Step 1. Design

What counts as one registered product

Everything inside the dashed boundary below forms one registered product. Change any numbered element and you have a second product to model, certify and register.

#	Element	What defines it in the submission
1	Heat pump unit	Model name, refrigerant and charge, rated capacity, matched exactly to the AS/NZS 5125.1 report and the data plate
2	Condenser	Wrap-around coil, microchannel strip, in-tank coil or external heat exchanger, with tube or strip geometry, material and bonded position
3	Storage tank	Model, internal volume, internal diameter and height, wall thickness, insulation thickness and conductivity
4	Control sensor	Height above the tank base and the tank volume above it, which together decide how much of the tank the heat pump actually controls
5	Booster element	Capacity in kW, thermostat height, set point, dead band, and its priority against the heat pump
6	Controller	Default factory mode, heat pump set point and dead band, sanitisation temperature and frequency, low-ambient cutover
7	Household draw	The AS/NZS 4234 load the product is registered against

Element 4 is the one most often underestimated. Two otherwise identical tanks with the sensor 100 mm apart will hold different useful volumes, deliver different minimum temperatures and earn different certificate counts.

Integral or separate

The two architectures are documented and modelled differently, and the split decides what evidence you need to collect.

The Appendix G rule catches out separate-system ranges regularly. The test count is driven by the heat pump and tank pairings you intend to sell, not by the number of heat pumps, so settle the pairing list before booking laboratory time.

The eligibility floors

Six rules decide whether a design is worth registering at all. Check them before spending anything on testing.

1. Insulated storage volume. SRES is limited to products under 425 L. VEU and ESS accept up to and including 700 L. A 500 L product is a two-scheme product, not a three-scheme one.
2. Minimum delivery temperature. AS/NZS 4234 requires delivered water at 45°C or above through the peak draw. This is the criterion that fails most often, and a wide temperature dead band is the usual cause.
3. Annual energy savings. At least 60% against the AS/NZS 4234 reference system, at the load size the product is registered for. Below that the product is not eligible.
4. Refrigerant. VEU requires the refrigerant to appear on its own list with a GWP below 700, mandatory since 1 July 2024. That ruled out R-410A and R-134a products and pushed the market to R-290 and CO2.
5. Warranty. A minimum five year warranty against defects has applied to VEU Activity 1D and 3C since 31 March 2025, and to ESS products with 700 L or less of insulated storage since 1 December 2025. Every residential product sits under that threshold, so the requirement covers the whole range.
6. Electrical safety. A Certificate of Approval citing AS/NZS 60335.2.21 for pressure storage water heaters and AS/NZS 60335.2.40 for the heat pump, plus EESS or RCM registration in the applicant’s own entity.

Preliminary modelling

Preliminary modelling runs an indicative AS/NZS 4234 simulation from data you already hold: internal or catalogue heat pump performance, a tank drawing, and your control logic. It shows roughly where the certificate numbers land before you commit to laboratory testing.

It cannot be lodged with any of the three schemes. Certificate-earning results need AS/NZS 5125.1 data from an accredited laboratory. Its value is answering the go or no-go question, and sizing the gap to the 60% savings and 45°C delivery gates, for a fraction of the cost of a test round.

Where the question is whether the underlying design has the COP headroom at all, a first-principles physics model of the compressor, condenser, evaporator and stratified tank is the better tool, because it can be run before a prototype exists.

Step 2. Test

AS/NZS 5125.1 performance testing

AS/NZS 5125.1 is the single most consequential document in the whole process. It measures thermal capacity, power input and COP through full heat-up cycles at four air conditions in a controlled chamber, plus a low-temperature test that characterises frosting behaviour. From that data the laboratory fits the COP and power regressions that the annual simulation interpolates across.

Those regressions set the ceiling on everything downstream. They cannot be improved later by remodelling. Fixing an underperforming map means a design change and a full retest, which is why checking design headroom before the test matters more than optimising afterwards.

Confirm the following with the laboratory before the unit goes on the bench:

• The four required air test conditions are run within their specified dry bulb and dew point windows, with no duplicated points. A test point period whose average sits outside its band is a conduct non-conformance, and the fix is a retest.
• The low-temperature test is run if low-temperature performance is to be claimed, since the condition chosen affects the ambient limit below which a performance penalty applies in the annual model.
• Standby power is measured at the reference condition.
• For a separate heat pump, the tank used for testing meets the standard’s requirement and the condenser water flow rate sits within 20% of the installation manual value.
• Raw time-series data is supplied for the low-temperature condition, and for integral products also for the second test condition, so the frosting penalty and the tank heat transfer can be calibrated.

Tank, safety and water certification testing

The AS/NZS 4692.1 standing heat loss test gives the tank loss figure the model uses. Read it from the 4692.1 report, not from a summary table in the performance report, and make sure the tank model on it matches the drawing and the certificate schedule.

Electrical safety testing and certification runs in parallel and should start in step 1. It is the most common cause of a late application, because the AS/NZS 2712 certificate depends on it and the scheme submission depends on the 2712 certificate.

What makes a test report unusable

A technically correct report can still be rejected. The recurring reasons are all avoidable:

• No verifiable digital signature. IPART and the ESC both reject unsigned reports. Where the signature cannot be validated, the laboratory has to email the report directly with a validity confirmation, which adds weeks if it is discovered at assessment.
• A draft. An unstamped or watermarked draft cannot be lodged.
• Older than ten years. The NSW HEER guide will not accept a test report ten years old or more at the date of application.
• A laboratory without accreditation evidence. NATA accreditation, or a recognised equivalent, has to be evident on the report itself. A general claim of satellite-laboratory status or a set of IEC certificates is not the same thing.
• Missing regression evidence. The report has to contain the COP and power regression graphs with their r-squared values, the start and finish point measured data, the lowest air temperature used for testing, and an explanation of any outliers.

Appendix H and MEPS

AS/NZS 5125.1 Amendment 1, published on 22 May 2026, added a new normative Appendix H: a performance test method reporting maximum hot water delivery and a cycle COP across cold, average and hot conditions. It sits ahead of incoming GEMS MEPS requirements for residential heat pump water heaters.

Two points matter for planning. Appendix H applies to potable hot water only and to a single storage tank up to 700 L, so a combined unit doing domestic hot water plus space heating or cooling sits outside the method entirely. And no MEPS levels have been published, so the objective is not clearing a threshold, it is the highest achievable Appendix H figure, because that is the number that will be public and comparable whatever level is eventually set. The Appendix H guide covers the method in detail.

Step 3. Model

The AS/NZS 4234 model is a TRNSYS simulation of the whole product across a full year, in each climate zone the schemes publish. It takes the performance regressions from step 2 together with the physical and control description of the product, and produces the numbers every application rests on.

1. Performance mapThe AS/NZS 5125.1 COP and power regressions become the map the simulation interpolates across, with a frosting penalty derived from the low-temperature test data.
2. CalibrationFor integral products the tank heat transfer is calibrated against raw second-condition test data. AS/NZS 4234 Amendment 1, effective 1 June 2026, replaces that calibration with a physical condenser model for integral units in VEU and ESS work.
3. Product modelTank geometry, standing heat loss, sensor height and the volume above it, element capacity and thermostat position, set point, dead band and the sanitisation cycle are assembled into the template that matches the architecture.
4. Annual simulationAn hour-by-hour year in each climate zone, against the AS/NZS 4234 household draw profile, run once under the 2008 edition for SRES and again under the 2021 edition for VEU and ESS.
5. Eligibility checkMinimum delivery temperature at or above 45°C, and annual energy savings at or above 60% at the registered load size. Failing either stops the registration for that zone.
6. Certificate quantitiesThe scheme equations convert the modelled boost and element energy into STCs, VEECs and ESCs, per zone and per activity.

A product can be accepted for one zone and not another. Where the 60% savings threshold is met in zone 3 but missed in zone 5 by a small margin, the NSW listing covers zone 3 only and certificates follow for that zone alone. That is a normal outcome, not a failed application.

The settings that still move the result

The performance map is fixed once the unit has been tested. The control settings are not, and they can be swept against the real test data right up until submission. Set point, dead band, sensor height and the volume above it, element behaviour and priority, sanitisation temperature and frequency, and insulation thickness all move the result.

This is the cheap, late lever, and it is where most of the recoverable value sits. It only works when the settings that get modelled are the settings that ship: the manual, the control declaration and the model all have to describe the same behaviour, and a mismatch between them is one of the most common requests for information across all three schemes.

EnergyAE confirms the modelling results with you before certificate quantities are finalised, so the numbers the registration rests on are approved before anything is lodged. For more on the conversion itself, see how residential HPWH results become certificates.

Step 4. Certify

Product certification is separate from the scheme certificates, and it is where schedules usually slip. The AS/NZS 2712 certificate is the gate: no scheme submission proceeds without the product’s exact market model name appearing on a current 2712 certificate schedule.

The 2712 certificate depends on the electrical safety certificate, the tank test, the AS/NZS 5125.1 report and the AS/NZS 4234 report all being in hand, so it is the last thing to arrive and the first thing to plan. Work with an Accredited Certification Body such as SAI Global or IAPMO to confirm the exact test set your product needs before testing is booked, because a test program built for one pathway can leave gaps in another.

Where the product is sold under an importer’s brand rather than the manufacturer’s, the model name still has to be on a valid schedule. Either the manufacturer adds it to their existing certificate, which is faster and cheaper but makes the relationship visible, or the importer takes out their own certificate. The white-label registration guide covers that decision.

What each scheme asks for

The three schemes want the same technical evidence and different administrative evidence.

The warranty condition

The warranty text can sit inside the installation or owner manual. A standalone document is not required, but the text has to carry all of the following:

• A minimum five year term, stated from installation, purchase or supply.
• Australian contact details for warranty claims: a name, business address, phone number and email.
• What the consumer must do to make a claim, and who bears the cost of claiming.
• The mandatory Australian Consumer Law paragraph, reproduced word for word as its own standalone paragraph.

Check the component warranties too. A PTR valve listed at one year inside an otherwise compliant five year warranty is enough to send an application back.

Step 5. Register

Portal accounts should exist and be tested before the pack is ready, because account setup, identity checks and signatory approval all take longer than the lodgement itself. See setting up your VEU and TESSA portal accounts.

1. Confirm the exact model names that will appear in the public listings. They must match across the AS/NZS 5125.1 report, the AS/NZS 4692.1 report, the 2712 certificate schedule, the tank drawing, the data plates, the manual, the technical details sheet and every declaration. Name mismatches are the single most common cause of rework, and they multiply where the same physical unit is sold under an OEM name and one or more local brands.
2. Lodge the SRES application through the CER portal, against the current application round. CER runs three rounds a year with a firm cutoff, and products are normally published three to four months after the round closes. Missing a cutoff costs a quarter, so the round date works backwards into the test booking.
3. Lodge the VEU application through the VEU Registry, selecting the residential heat pump product category. Choosing either Activity 1D or 3C lists the product for both, so there is no need to apply twice. See how to submit a HPWH application through the VEU Registry.
4. Lodge the ESS application through TESSA under the HEER method, which auto-populates activities D17 and D19. A maximum of eight products goes in one application, files are uploaded individually because TESSA does not accept ZIPs, and duplicate model numbers are rejected automatically. See how to submit a residential HPWH through TESSA.
5. Answer requests for information. CER is comparatively forgiving, because applications are batched and published together, and outright rejection is rare. VEU and ESS assess each application individually, so a request there costs more. NSW allows up to two rounds with 90 days to respond, and Victorian applications left unanswered are withdrawn automatically.

After listing

Registration is not the end of the evidence trail. CER audits products already on the register, sweeping a set of listings with each register version, and an audit asks for the same consistency the original application did: the drawing against the technical details sheet, the report figures against the model, the manual against the declaration. Products get selected on a routine basis rather than for cause, so an audit notice is not a signal that something is wrong.

Keep the submitted pack, the TRNSYS files and the reasoning behind any calculated parameter. The gap between a two-day audit response and a two-month one is almost entirely whether that material is still to hand.

Documents to have ready

Model names must be consistent across every document. Send searchable PDFs rather than scans, and clear photographs of data plates.

Step	Document	Notes
2	AS/NZS 5125.1 test report	Signed and stamped, accredited laboratory, less than 10 years old, with the regression graphs and r-squared values
2	Raw test data	Time series for the low-temperature condition, plus the second condition for integral products
2	AS/NZS 4692.1 heat loss report	Tank model must match the drawing and the certificate schedule
1, 3	Tank drawing	Dimensioned engineering drawing with a parameter table: internal volume, diameter, height, wall thickness, insulation spec, and the height of every inlet, outlet, element boss, thermostat pocket and sensor
1, 3	Condenser detail	Coil tube length, inner diameter, wall thickness and material, or microchannel strip length, count and bond position
1, 3	System schematic	Separate systems: the full water circuit, pump model and location, flow direction, sensors and element
3	Control declaration	Signed statement of default mode, set point, dead band, controlling sensor, booster logic, sanitisation temperature and frequency, and low-ambient behaviour
4	AS/NZS 2712 certificate and schedule	Must list every market model name being registered
4	Electrical safety evidence	Certificate of Approval plus EESS or RCM registration, in the applicant entity
4, 5	Warranty evidence	Five year term, Australian claim contact, and the Australian Consumer Law paragraph verbatim
5	Installation manual	Digitally searchable, English, covering every model, with controller modes, factory defaults, sanitisation description and the warranty
5	Data plate images	Legible model name, electrical ratings, refrigerant type and charge, tank capacity and certification marks
5	Applicant company details	Legal name, ABN, address, and the authorised signatory’s details
5	Authorisation or equivalence declaration	Where the applicant does not own the test reports, or where model names differ between documents

The full version, with what each document has to show, is in the residential HPWH documentation checklist.

Common causes of delay

1. Model names that do not match across the test reports, 2712 schedule, data plate, drawing and manual. This is by far the largest single cause, and it is worst where one physical unit is sold under an OEM name plus several local brands.
2. Test reports without a verifiable signature, which cannot be lodged and need a laboratory validity confirmation to rescue.
3. Electrical safety certification started late, which holds up the 2712 certificate, which holds up all three applications.
4. Control settings in the manual that contradict the control declaration, usually a set point or dead band that was changed in one document and not the other.
5. A tank drawing without sensor and fitting heights, or a brochure render supplied in place of an engineering drawing.
6. Portal accounts and authorised signatories left until the pack is ready. NSW signatory approval needs an ASIC company extract and certified identity documents, and it routinely takes longer than the modelling did.
7. A specification change after modelling: a new tank diameter, a different element capacity, a revised sensor position. Any of these sends the work back to the start of step 3, and sometimes to step 2.

Common questions

Next steps

If you are developing a residential HPWH and want to know what it will earn under SRES, VEU and ESS before committing to a test round, get in touch with the heat pump model, tank drawing and control settings you have. For the full document list, see the residential HPWH documentation checklist, and for the portal setup that has to happen alongside the technical work, see setting up your VEU and TESSA portal accounts.