Rinnai HydraHeat Integrated · 340L ownership guide
Rinnai HydraHeat 340L.
Choose the system, not just the litres.
The HydraHeat Integrated 340L, order code RHPN361A340E20, pairs a storage cylinder with a removable heat-pump head. Check siting, daily operating time and the exact version’s controls before choosing it for a Lower Hutt home.
Hot Water Now is the specialist hot-water service of Water & Gas Plumbing Ltd, serving Lower Hutt.
Know which HydraHeat is on the quote.
The complete 340L Integrated order code is RHPN361A340E20. The head and cylinder form a matched system. Rinnai’s guide says the head must not be installed with a cylinder other than the HydraHeat cylinder; a generic existing tank is not a drop-in match.
The assembled 340L model is 1,995mm high and 692mm in diameter. Its nominal storage volume is not a guaranteed number of showers. Rinnai publishes recovery of 89L/hour measured in Eco 55 at 19°C ambient air with a 36°C water-temperature rise. That test is not a guaranteed Lower Hutt winter recovery rate.
The stated operating range is −10°C to 42°C. Cold-weather operation does not establish constant efficiency or recovery throughout that range. Size the system for consecutive use, not just household headcount. Use the cross-brand guide if you are deciding whether a different tank size, controls or package is a better fit.
Use the current installation guide for clearances.
Rinnai describes the unit as primarily designed for outdoor installation. An indoor proposal needs specialist assessment of the unoccupied space, ventilation and applicable requirements; do not assume it belongs in an old cylinder cupboard.
The reviewed installation guide, revision N, shows minimum clearances of 400mm to either side, 500mm above and 40mm behind the unit. Its rear gap allows airflow, limits vibration noise and permits cleaning. Check the complete current drawing and the actual supplied model; these figures are not a substitute for an installer’s site assessment.
The base must be level, stable, water-impervious and able to support the full system. Allow safe drainage, readable labels, access to the controls and service covers, and a suitable route for getting the unit into position. Rinnai warns against direct sea wind and salt spray, so exposure needs a real assessment at coastal Lower Hutt properties.
Discuss nearby bedrooms and neighbouring boundaries. Rinnai’s published 45dB(A) sound-pressure figure is at 1m in a free field, Standard mode at 60°C, with 19°C ambient air. It is not a prediction of sound at your boundary or a direct comparison with an unqualified noise figure from another brand.
Modes and timers affect recovery and running cost.
The controller offers Standard, Boost, Eco 55, Eco 50, High Usage and Element Only modes. The appropriate choice depends on demand and the supplied instructions. Have normal operation and occasional high-demand use explained at handover rather than changing temperatures to try to maximise an advertised saving.
The two programmable timers can change when or how the unit operates. A timer set to Shutdown prevents heating during that window; it is not simply a reminder. Rinnai’s operating guide warns that restricting operation to a short free-power period limits the amount of hot water produced and can prevent the disinfection cycle completing. Ask for a schedule that allows sufficient heating time and the hygiene and protection functions to operate.
In some faults the system switches to Element Only. Hot water may still be available, but the electric element alone does not deliver normal heat-pump operation and can increase power use. Note the code and contact the installer or Rinnai rather than leaving a recurring fault unresolved.
Solar-PV compatibility depends on the unit version.
The reviewed revision N installation guide identifies solar-PV compatibility for units manufactured from July 2026, serial number WGZABX2321 inclusive and onwards. Do not assume every older HydraHeat Integrated has the same smart-connection capability.
Ask the installer to confirm the supplied unit’s serial number, the compatible solar-control arrangement and the additional work, if any. The manual describes a control connection; this is different from simply having rooftop solar on the house. A system can draw grid electricity when generation is insufficient, and a PV connection is not a guarantee of free water heating.
No solar-control installation, inverter change or electrical upgrade is automatically added to the advertised offer by this guide. The agreed quote should say what is included.
The approved Rinnai installed offer
$7,749 + GST
$8,911.35 including GST. Gas conversion adds $300 + GST, giving $8,049 + GST ($9,256.35 including GST).
Subject to a site visit and confirmation of installation requirements. Full installation scope, additional work and supply availability are confirmed before agreement. Panasonic’s inclusion list does not automatically apply to this package. Confirm the base, electrical supply, valves, drainage, old-system removal, gas work and any PV-control connection.
Choose Rinnai explicitly in the replacement calculator. Its heat-pump package rules require known electric/gas existing equipment, known capacity, mains pressure and the same location. Relocation, an existing heat pump or uncertain details need assessment. The online result is not a booking or technical approval of the location.
Plan for servicing, and know what to report.
Rinnai recommends professional servicing every two years. Its operation guide describes checks including the evaporator, condensate drain, connecting hoses, seals and leaks; firmware and the clock battery may also need attention. Regular maintenance is not covered by Rinnai’s warranty. This guidance is not an included Hot Water Now service plan.
Keep the invoice, installation details, model and serial numbers, operating guide and service history. Ask for the manufacturer’s homeowner checks to be explained safely. Covers, electrical connections and refrigerant components are not homeowner maintenance tasks. Do not block relief outlets, and do not drain the system yourself.
If the display shows L during the disinfection cycle or D during defrost, Rinnai says those are not fault codes. An event code or repeated warning should be recorded and reported with the symptoms. Do not assume every cold-water complaint is a failed heat-pump head: settings, supply, demand and plumbing faults also need consideration.
For an extended absence in frost-prone conditions, discuss the manufacturer’s guidance before disconnecting power. Freeze protection relies on power; Rinnai says draining, when required, is work for an authorised person. Warranty eligibility, water quality and responsibility for any repair need checking against the current terms rather than a blanket assumption of free cover.
Specific to this model
Questions before choosing
Can I keep any existing cylinder and add the HydraHeat head?
No. Rinnai’s instructions require the matched HydraHeat cylinder. Assess the exact existing system rather than treating a removable head as universal compatibility.
Does an L or D on the display mean a breakdown?
Rinnai identifies L as the disinfection cycle and D as defrost, not fault codes. If hot water is insufficient, a warning persists or you are unsure, record the display and symptoms and contact the installer or Rinnai.
Can every HydraHeat Integrated use the newer PV smart connection?
Do not assume that. The reviewed installation guide limits that compatibility to units manufactured from July 2026, serial WGZABX2321 inclusive and onwards. Confirm the supplied unit and control arrangement before agreement.
Official sources and scope
Manufacturer information checked 16 September 2026. Read the current instructions and terms for the exact supplied model before ordering. These homeowner notes do not replace installation instructions. Installed prices are Hot Water Now offers, not manufacturer prices. No manufacturer-authorised service appointment is claimed.
- Rinnai NZ HydraHeat Integrated product page — identity, specifications and conditioned ratings
- Rinnai installation guide revision N — matched system, clearances p.12 and PV version requirements pp.6,32–33 (PDF)
- Rinnai operation guide revision L — timers, maintenance and display codes (PDF)
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Lower Hutt homes and rental properties
Bring the model.
Check the site.
Call with your suburb, current system, proposed location and busiest hot-water period. Availability, the work required and charges are confirmed before agreement. Viewing this guide does not book a visit.