Rheem Electric Domestic Water Heater
Owners Guide and Installation Instructions
Notice to Victorian Customers
This water heater must be installed by a licensed person as required by the Victorian Building Act 1993. Only a licensed person will provide a Compliance Certificate, showing compliance with standards and offering 6 years of insurance for their workmanship. Ensure you use a licensed person and ask for your Compliance Certificate.
PATENTS
This water heater may be protected by one or more patents or registered designs.
® Registered trademark of Rheem Australia Pty Ltd.
TM Trademark of Rheem Australia Pty Ltd.
About Your Water Heater
Congratulations on choosing a Rheem® water heater. Models include Rheemglas®, Optima™, or RheemPlus™. The Optima model features a temperature adjusting knob on the lower front. Rheemglas and Optima models are available with single or twin heating units, while RheemPlus models are single-heating unit only.
How Hot Should the Water Be?
The water heater has an adjustable thermostat. Refer to "Temperature Adjustment" on page 5. A RheemPlus water heater is temperature limited to 50°C. The National Plumbing Standard requires stored water temperature to be not below 60°C. For solar water heating systems, a thermostat setting of 60°C is recommended for maximum solar contribution.
Diagram Description: A thermometer graphic showing temperature settings from 35°C to 75°C, with markers indicating "Optima maximum thermostat setting", "Rheemglas and RheemPlus maximum thermostat setting", "minimum thermostat setting and minimum recommended stored water temperature", "top heating unit thermostat setting on a twin element model (not adjustable)", and "RheemPlus maximum delivery temperature / maximum recommended supply temperature to bathrooms and ensuites".
Hotter Water Increases the Risk of Scald Injury
This water heater can deliver water at temperatures that cause scalding. Always check water temperature before use. It is recommended that an approved temperature limiting device be fitted to the hot water pipework to bathrooms and ensuites for Rheemglas or Optima heaters to keep water temperature below 50°C at these outlets, while allowing hotter water for the kitchen and laundry.
Temperature Adjustment
Optima Model: Features a user-adjustable thermostat. Push the child-resistant knob and turn anticlockwise to decrease or clockwise to increase temperature. Minimum setting is 60°C, maximum is 75°C.
Rheemglas or RheemPlus Model: Features a tradesperson-adjustable thermostat requiring a licensed tradesperson. Maximum setting is 70°C, minimum is 60°C.
Diagram Description: An illustration of the Optima thermostat adjustment mechanism, showing the knob, connector shaft, thermostat adaptor, and locking tabs.
It is advised to set the thermostat to the lowest temperature meeting your needs, especially if young children or elderly people are present. A RheemPlus water heater is limited to 50°C at the outlet; increasing the thermostat setting will not increase outlet temperature but may provide more hot water capacity.
WARNING
This water heater is intended for operation by persons with experience and knowledge. It is not for use by persons with reduced physical, sensory, or mental capabilities, or by children. Children should be supervised. The heater uses 240 V AC power; removing covers exposes 240 V wiring and must only be done by an authorised person. If fitted with a cord and plug, use a weatherproof outdoor outlet. Do not touch the plug with wet hands.
SAFETY
The water heater is equipped with a thermostat, over-temperature cut-out, and a combination temperature pressure relief valve. RheemPlus models also have a temperature limiting valve. These devices must not be tampered with or removed. The heater must not be operated unless these devices are fitted and working. Damaged power cords or plugs must be replaced by an authorised person with genuine Rheem parts. Warranty may be void if safety devices are tampered with or installation is not in accordance with instructions.
To Turn Off the Water Heater
For short absences (a few nights), leave the heater switched on. If necessary to turn off:
- Switch off the electrical supply at the isolating switch.
- Unplug the power supply cord (if applicable).
- Close the cold water isolation valve.
To Turn On the Water Heater
- Open the cold water isolation valve fully.
- Plug in the power supply cord (if applicable).
- Switch on the electrical supply at the isolating switch.
Installation Correctness and Water Quality
Installation must comply with AS/NZS 3500.4, AS/NZS 3000, local codes, and NZ Building Code. Water quality can affect the heater; check with your local water supply authority if unsure. The heater is suitable for most public water supplies.
How Long Will the Water Heater Last?
Lifespan depends on water quality, pressure, temperature, and usage patterns. The Rheem water heater is supported by a comprehensive warranty.
Anode Protection
The anode dissipates to protect the cylinder. Its life can be extended by inspection and replacement by an authorised person. Suggested inspection times: Rheemglas & RheemPlus: 8 years; Optima: 10 years. For softened or poor water quality, inspect 3 years earlier.
How Your Water Heater Works
Water is stored in a vitreous enamel lined steel cylinder and heated by an electric immersion unit controlled by a thermostat. Automatic safety controls ensure safe and efficient operation.
Mains Pressure
The heater is designed for mains pressure. If supply pressure exceeds limits shown on page 16, a pressure limiting valve is required. Supply pressure should be greater than 350 kPa for true mains pressure operation.
Thermostat
The thermostat controls electricity to the heating unit to maintain temperature. It includes an over-temperature cut-out. It is fully automatic and only uses power when heating is required. No need to switch off unless on extended holiday.
Single Element Model
Features one heating unit with its own thermostat, located at the base. Connection can be continuous electricity supply (suited for capacity less than daily usage) or Off-Peak electricity supply (heating during set hours, more economical).
Diagram Description: An illustration of a single element electric water heater.
Twin Element Model
Has two heating units, each with a thermostat, located at the base and near the top.
- Bottom heating unit: Supplies all hot water during normal operation.
- Top heating unit (Booster): Operates during high demand for additional heated water.
- Electrical connection: Wired for non-simultaneous operation (only one unit operates at a time). Bottom unit usually connected to Off-Peak, top to continuous supply. Some suppliers meter both at Off-Peak.
NOTE: Power must be available to the top heating unit circuit at all times for proper operation.
Going on Holiday?
Leave the heater on for one or two nights. For longer periods, conserve energy by switching it off at the switchboard or isolating switch.
Regular Care
Temperature Pressure Relief Valve
Located near the top, essential for safe operation. May release a small amount of water during heating due to expansion (approx. 1/50 of volume). Continuous leakage may indicate a problem. Warning: Never block the outlet or drain line. Operate the easing lever gently every six months. DANGER: Failure to do so may result in cylinder failure or explosion. If water does not flow freely, contact Rheem Service. Check performance or replace every 5 years, or more frequently in areas with water deposits.
Diagram Description: An illustration of the Temperature Pressure Relief Valve on top of a water heater, with a close-up showing the lever and drain line connection.
Temperature Limiting Valve (RheemPlus)
Set to deliver water not exceeding 50°C. Check performance every twelve months by measuring hot tap temperature. If over 50°C, contact Rheem Service. Replace every 5 years, or more frequently in areas with water deposits. Failure may result in water up to 70°C at the tap, increasing scald risk.
Expansion Control Valve
Fitted to the cold water line in many areas (e.g., South Australia, Western Australia) or in scaling water areas. May discharge water from its drain line during heating. Operate the easing lever gently every six months. Check performance or replace every 5 years, or more frequently in areas with water deposits.
Save a Service Call
Not Enough Hot Water (or No Hot Water)
- Check if electricity is switched on at the isolating switch and switchboard.
- Check the relevant fuse at the switchboard.
- For twin element models, ensure power is available to the top heating unit circuit at all times.
- Consider if more hot water is being used than usual. Have your plumber fit flow control valves to shower outlets to reduce usage.
- Check if the temperature pressure relief valve is discharging excessively (refer to page 13).
- Ensure the thermostat setting is appropriate. Adjust upwards for more capacity if needed (Optima model user-adjustable, Rheemglas/RheemPlus by electrician). Warning: Hotter water increases scald risk.
Diagram Description: An illustration of a person looking at a shower head and taps.
Water Heater Size
Ensure you have the correct size water heater for your requirements. Refer to the Rheem sizing guide on their website (www.rheem.com.au).
Water Temperature Too High (RheemPlus)
A RheemPlus heater has a temperature limiting valve set to 50°C. If water is delivered above 50°C, contact Rheem Service. Exercise caution when using hot water until the valve is serviced or replaced.
Temperature Pressure Relief Valve Running
- Normal Operation: Small water discharge during heating is normal. More than a bucket in 24 hours may indicate a problem.
- Continuous dribble: Try gently raising the easing lever for a few seconds to dislodge debris.
- Steady flows (often at night): May indicate high mains pressure. Ask your plumber to fit a pressure limiting valve. Warning: Never replace the relief valve with one of a higher pressure rating.
- Heavy flows of hot water until water heater is cold - then stops: Switch the water heater off at the switchboard and contact Rheem Service.
Diagram Description: An illustration of a water heater with a relief valve and drain line.
Expansion Control Valve Running
If fitted, it may discharge water instead of the TPR valve. This conserves energy as the discharged water is cooler.
High Electricity Bills
- Check if the relief valve is running excessively.
- Check if one outlet is using more hot water than you think.
- Check for leaking hot water pipes or taps. Even small leaks waste water and electricity.
- Consider recent changes to hot water usage patterns or electricity tariffs.
Diagram Description: An illustration of a hand holding an electricity bill with dollar signs.
Electricity Tariffs
Tariffs (Off-Peak, Extended Off-Peak, Continuous) affect operating costs. Refer to "Single Element Model" (page 8) and "Twin Element Model" (page 9) for details.
If you have checked all the above and still need assistance, call your nearest Rheem Service Department or Accredited Service Agent.
Installation
THIS WATER HEATER IS NOT SUITABLE FOR POOL HEATING.
Water Heater Location
Suitable for outdoor or indoor installation (cord/plug models for indoor only). Install close to the most frequently used outlet, considering safety and service. Ensure adequate clearance for servicing, accessibility of TPR valve, thermostat, and covers. The rating plate must be readable. Leave headroom for anode inspection/replacement. Installation must comply with AS/NZS 3500.4, AS/NZS 3000, local codes, and the New Zealand Building Code. Install at ground or floor level, vertically upright. Check local authority regulations for roof space installations.
Diagram Description: An illustration of a house with an outdoor water heater installation, showing connections and components.
Safe Tray
AS/NZS 3500.4 requires a safe tray for new installations to contain leaks. Construction, installation, and draining must comply with the Standard.
Mains Water Supply
If mains pressure exceeds table values, an approved pressure limiting valve is required. The table shows relief valve setting, expansion control valve setting, and maximum mains supply pressure for different models.
Diagram Description: An illustration of a pressure gauge connected to a water line, showing pressure readings.
Tank Water Supply
If supplied from a tank without a pressure pump, the tank must be at least 1m above the highest point of the hot water plumbing system. Avoid air locks. The cold water line should be adequately sized and fitted with a full flow gate valve or ball valve.
Hot Water Delivery
The heater can deliver scalding water. A temperature limiting device is recommended for bathrooms/ensuites to meet AS/NZS 3500.4 requirements. Installation of this device involves branching off the cold water line, with specific valve order (isolation, pressure limiting, non-return) before the heater. If an expansion control valve is required, it must be installed after the non-return valve.
Diagram Description: A diagram illustrating "Two Temperature Zones Using a Temperature Limiting Device", showing cold supply, water heater, temperature limiting device (TLD), and outlets for kitchen/laundry and bathroom/ensuite. Notes indicate requirements for non-return valves (NRV) and pressure limiting devices (PLD).
Circulated Hot Water Flow and Return System
RheemPlus water heaters cannot be part of a circulated system. For other Rheem heaters in such systems, a storage water heater providing at least 60°C outlet temperature is required. Temperature limiting devices cannot be circulated and must be installed on a dead leg. Improper installation can lead to scalding or device failure.
Diagram Description: A diagram illustrating the RheemPlus 50°C Max Outlet Temperature TLD.
Diagram Description: Diagrams showing "Circulated Hot Water Flow and Return – Continuous Electric Water Heater" and "Circulated Hot Water Flow and Return System – Off-Peak Electric Water Heater".
Reducing Heat Losses
Insulate cold and hot water lines according to AS/NZS 3500.4. Insulation must be weatherproof and UV resistant if exposed.
Anode Types
Use the correct anode type based on Total Dissolved Solids (TDS) in the water supply. Black anode is standard. For TDS > 600 mg/L, replace with a blue anode. For TDS < 40 mg/L, use a green anode. Anode changing must be done by a plumber or qualified service person.
Table Description: A table listing "Total Dissolved Solids in water supply to the water heater" (0-40 mg/L, 40-600 mg/L, 600-2500 mg/L) and corresponding "Anode colour code" (Green, Black, Blue).
Push Through (Free Outlet) Installation
This installation method can supply a single point and typically uses a 25 or 50 litre electric water heater. The supplied temperature pressure relief valve must be fitted.
Diagram Description: A diagram illustrating a "Push Through (Free Outlet) INSTALLATION" setup.
Saddling Pipe Work
To prevent cylinder damage when attaching pipe clips or saddles, use self-drilling screws (max 12mm length). Exercise caution when penetrating the jacket. Damage to the cylinder from saddling voids the warranty.
Typical Installation Diagrams
Diagram Description: An illustration for "TYPICAL INSTALLATION – OUTDOOR LOCATION" with labels for Hot Water Outlet, Temperature and Pressure Relief Valve (T & PR Valve), T & PR Valve Drain, Temperature Limiting Valve Cover (RheemPlus models only), Cold Water Connection, Cable Connection, Rating Label, Booster Heating Unit and Thermostat Cover (Twin Element Models Only), Heating Unit and Thermostat Cover, and Temperature Adjusting Knob (Optima Models Only).
Diagram Description: An illustration for "TYPICAL INSTALLATION – INDOOR LOCATION" with labels for Cold Water Connection, Safe Tray with Drain, and Water Heater Support.
Dimensions and Technical Data
Diagram Description: Diagrams showing the dimensions (A through L) of the water heaters.
Table Description: A table detailing "Rheemglas and Optima" and "RheemPlus" models, including model numbers, hot water delivery (Litres), boost capacity (Litres), dimensions (A-L in mm or degrees), and approximate weight empty (kg). Notes explain connection types and model prefixes.
Connections – Plumbing
Connection Sizes
Rheemglas, Optima: Hot water connection: RP ¾/20; Cold water connection: RP ¾/20; Relief valve connection: RP ½/15.
RheemPlus: Hot water connection: G ¾ B; Cold water connection: G ¾ B; Relief valve connection: RP ½/15.
All plumbing work must be carried out by a qualified person in accordance with AS/NZS 3500.4 and local authority requirements.
Water Inlet and Outlet
Clear pipework of foreign matter and purge before operation. Use brass or copper olives for compression fittings. Use thread sealing tape or sealant. An isolation valve and non-return valve must be installed on the cold water line. A disconnection union must be provided at the cold water inlet and hot water outlet for disconnection. The water heater has a plastic dip tube or fitting liner in the inlet/outlet fittings; ensure these are in place.
Diagram Description: A diagram showing an "EXPANSION CONTROL VALVE" setup with STOPCOCK, NON-RETURN VALVE, PRESSURE LIMITING VALVE (if required), and connections to the water heater. Also shows a "DIPTUBE OR FITTING LINER" in the inlet or outlet fitting.
Expansion Control Valve (ECV)
Local regulations may mandate an ECV in the cold water line. It is not required unless the saturation index is greater than +0.4 (refer to "Water Supplies", page 33) or in corrosive water areas. The ECV must be installed after the non-return valve and be the last valve before the water heater. A separate copper drain line is required.
Left and Right Hand Side Water Connections
Connections can be made on either side. A kit is supplied to plug off unused fittings. For Model 050, the kit includes brass plugs and plastic insulation caps.
Plugging Off Unused Connections – 050 model: Apply sealing tape/compound to plug threads, fit plugs to unused fittings (¾" for cold/hot, ½" for TPR valve), and fit plastic insulation caps over plugs.
Pipe Sizes
For true mains pressure, the cold water line should be the same size or larger than the hot water line. Pipe sizing should be done by competent persons according to application and local requirements.
Relief Valve
The temperature pressure relief valve is shipped with the heater and must be fitted before operation. Ensure the probe is not bent. Seal the thread with Teflon tape. If an insulation collar is supplied, place it over the valve body before fitting.
Diagram Description: A diagram showing the relief valve being fitted with Teflon tape and supplied insulation.
Relief Valve Drain
A copper drain line must be fitted to carry discharge clear of the heater. Connect using a disconnection union. The pipe should be as short as possible, fall continuously, and have no more than three right-angle bends. Use DN15 pipe. The discharge point must be visible, prevent injury/nuisance, and be within 9 metres of the valve. For freezing areas, insulate the drain line (max 300mm) and discharge into a tundish with a 75-150mm air gap. Warning: Pipework downstream must handle water exceeding 93°C.
Connections – Electrical
Power supply must not be switched on until the water heater is filled with water and a satisfactory megger reading is obtained. All electrical work must be done by a qualified person according to AS/NZS 3000 and local authority requirements.
Water Heater
Heaters without a cord/plug must connect directly to a 240 V AC, 50 Hz mains supply with an isolating switch. Heaters with a cord/plug must use a switched 240 V AC, 50 Hz outlet rated at 10 A.
Power Supply
Twin element models: Off-Peak (overnight) to the bottom heating unit, continuous to the top. Single element models: Off-Peak, Extended Off-Peak, or continuous supply, depending on size. Check with the local electricity authority. Off-Peak offers maximum savings.
A 20 mm flexible conduit is required for the electrical cable, connected with a 20 mm terminator. Connect wires directly to the terminal block and earth tab.
Thermostat Setting
Rheemglas/RheemPlus: Adjustable from 60°C to 70°C (50 litre model: 60°C to 75°C). Optima: 60°C to 75°C. Adjust by turning the adjuster/knob. Adjust Rheemglas/RheemPlus only when the isolating switch is off. Top thermostat on twin element models is fixed at 60°C.
For safety and economy, set the thermostat to the lowest temperature providing sufficient hot water. Dishwasher costs may increase if set below 65°C. For solar systems, 60°C is recommended for maximum solar contribution.
Assembly of Adjuster Mechanism on Optima Model
To reassemble after removing the front cover: Remove the knob by depressing locking tabs. Turn the thermostat to the lowest temperature. Fit the front cover. Insert the connector shaft into thermostat adaptor slots. Align knob slots over the 'T' drive on the connector shaft and push firmly to engage locking tabs.
Diagram Description: A diagram illustrating the assembly of the adjuster mechanism on the Optima model.
Wiring Diagrams
Diagram Description: Wiring diagrams for "Twin Element Electric Water Heaters Non-Simultaneous Operation Off-Peak Connection" for Robertshaw "EWT" Thermostats and Robertshaw "ST" Thermostats.
The active from the continuous supply connects to the top heating unit circuit, and the active from the Off-Peak or time controlled supply connects to the bottom heating unit circuit.
Commissioning
To Fill and Turn On the Water Heater
Do not switch power on until the heater is filled and a satisfactory megger reading is obtained. Open all hot water taps. Open the cold water isolation valve fully. Air will be forced out. Close taps as water flows freely. Check pipework for leaks. Plug in the power supply cord (if applicable). Switch on the electrical supply. Explain operation to the householder and leave the guide with them.
To Turn Off the Water Heater
If necessary (e.g., on a building site or vacant premises): Switch off the electrical supply, unplug the power supply cord (if applicable), and close the cold water isolation valve.
Draining the Water Heater
To drain:
- Turn off the water heater (refer to "To Turn Off The Water Heater", page 30).
- Close all hot water taps.
- Operate the relief valve release lever gently (do not let it snap back). This releases pressure.
- Undo the union at the cold water inlet and attach a hose to the heater side. Let the other end go to a drain.
- Operate the relief valve again. This allows air in, and water drains through the hose.
Water Supplies
The water heater is designed for most metropolitan water conditions but some may have detrimental effects. Obtain information from your local water supply authority. Connect only to a potable water supply.
Anode
In areas with TDS > 600 mg/L, the black anode may be active; replace with a blue anode. For TDS < 40 mg/L (e.g., deionised or alpine supply), use a green anode. Anode changing must be done by a plumber or qualified service person.
Caution
If TDS > 600 mg/L and the anode has not been changed to blue, hydrogen gas may accumulate during long periods of no use. In such areas, installers should instruct householders on safe gas dissipation. If the heater has not been used for two or more weeks, vent safely by opening a hot tap (no smoking or naked flame nearby) until water runs freely. Spurting indicates gas release.
Saturation Index
The saturation index measures water's corrosive or scaling properties. Corrosive water (index < -1.0) can damage copper parts; use a corrosion-resistant heating unit. Scaling water (index > +0.40) causes calcium carbonate deposits; fit an expansion control valve after the non-return valve. For index > +0.80, use a low watts density heating unit. Contact Rheem Service for replacement heating unit needs. Water heaters not installed according to advice will not be covered by warranty.
Rheem Mains Pressure Water Heater Warranty (Excluding Solar) - Australia Only
Warranty Conditions
- Applicable to water heaters manufactured from 1st September 2006.
- Must be installed per Rheem instructions and all relevant statutory/local requirements.
- Balance of original warranty period applies to replaced components/heaters.
- Costs for transport, insurance, and travel outside metropolitan areas or 25km from a Rheem office/agent are the owner's responsibility.
- Costs for safe access to the installation site are the owner's responsibility.
- Warranty applies only to the water heater and original/genuine components. It does not cover plumbing or electrical parts supplied by the installer (e.g., pressure limiting valve, isolation valves, etc.).
- Heater must be sized according to Rheem literature.
Warranty Exclusions
The following may void the warranty and incur service charges:
- Accidental damage, Acts of God, misuse, incorrect installation, unauthorized repairs.
- No fault found with the water heater, or issues related to high water pressure (TPR valve discharge), faulty plumbing (no hot water, leaks), or supply failures (gas, electricity, water).
- Failure due to excessive water pressure, temperature, thermal scale, corrosive atmosphere, or ice formation.
- Installation not complying with instructions or statutory requirements, necessitating major dismantling.
- Repair/replacement due to scaling or corrosive water, or water with high chloride/low pH levels.
Subject to statutory provisions, this warranty excludes claims for damage to furniture, carpets, walls, etc., or any consequential loss due to leakage.
Warranty Periods
Table Description: A table detailing warranty periods for "All Components", "Sealed System", and "Cylinder and SuperFlue" based on installation type (all installations, single-family domestic dwelling with thermostat setting below 76°C, any other dwelling with thermostat setting below 76°C) and model (Rheemglas, RheemPlus, Heat Pump, Stellar, Optima, Heavy Duty). Periods range from 1 year to 10 years. Notes clarify "Sealed System" components and labour coverage.
Rheem reserves the right to transfer functional components. This warranty is in addition to statutory rights under the Trade Practices Act 1974.
RHEEM AUSTRALIA PTY LTD
Α.Β.Ν. 21 098823511
www.rheem.com.au
FOR SERVICE TELEPHONE
131 031 AUSTRALIA
0800 657 335 NEW ZEALAND
or refer local Yellow Pages
NOTE: Every care has been taken to ensure accuracy in preparation of this publication. No liability can be accepted for any consequences, which may arise as a result of its application.
Revision Date: 2007 July
