Rheem electric hot water system troubleshooting

Are you having problems with your Rheem electric hot water unit?

If you have installed a Rheem, you have certainly made a wise choice. Rheem has been one of the leading hot water system brands in Australia for decades and is still going strong to this day. Needless to say, even though Rheem is a much loved and reliable system, there are times when something has gone a little wrong, and you will need to do a little troubleshooting.

We understand how frustrating this may be, and that’s why we have listed some of the issues you may encounter with your Rheem hot water system below and provided a solution.

It is important when troubleshooting to identify the issue, so you can determine why something is not working as expected. We hope the information here will help you get your system up and running as quickly as possible.

However, if you are still having problems please contact your local licensed plumber for professional advice.

Rheem electric storage hot water system common issues & solutions

Issue - Not enough hot water or no hot water

Is the electricity switched on?

Inspect the isolating switch marked “HOT WATER” or “WATER HEATER” at the switchboard and the isolating switch (if one is installed) near the water heater and ensure they are turned on.

Note: Check the electricity supply to which the water heater is connected. If on an Off-Peak or time-controlled electricity supply, remember heating hours are restricted.

Excessive use

Is one outlet (especially the shower) using more hot water than you think? Very often households do not realise how much hot water is used, particularly when showering. Carefully review the family’s hot water usage or ask a plumber to fit a flow control valve to each shower outlet to reduce water usage.

Relief valve running

Is the relief valve discharging too much water? Refer to“Temperature Pressure Relief Valve or Expansion Control Valve Running” on page 25 of the owner's guide.

Water heater is too small

Do you have the correct size water heater for your requirements?

The sizing guide in the Rheem sales literature and on the Rheem website suggests average sizes that may be needed.

Water not hot enough - thermostat setting

Ensure the thermostat setting is appropriate. You may choose to have a licensed plumber check and adjust the thermostat upwards to a higher temperature to gain additional hot water capacity.

WARNING: Hotter water increases the risk of scald injury.

You may also find that due to heavy hot water usage the water temperature may be lower than normally expected, due to insufficient heating time being allowed. You will need to carefully plan your use of the hot water on such occasions.

The water temperature is too high

A Rheem DualTEMP water heater is fitted with a temperature limiting valve. At the 50°C limited outlet on the left-hand side of the water heater. If water is being delivered from a fixture used primarily for personal hygiene at a temperature exceeding 50°C and supplied from this outlet call your plumber to arrange an inspection. Care must be taken by all householders when using hot water until the valve is serviced or replaced.

Temperature relief valve or expansion control valve running

Normal Operation

It is normal and desirable that the temperature pressure relief valve or expansion control valve (if fitted) allows a quantity of water to escape during the heating cycle. This quantity should be equal to approximately 1/50 of the hot water used, as the water expands by this volume when heated. However, if it discharges more than a bucket full of water in 24 hours, there may be another problem. The expansion control valve will discharge water instead of the temperature pressure relief valve as it has a lower pressure rating. A benefit is that energy is conserved as the discharged water is cooler. This valve Is installed in the cold water line to the water heater (refer to the cold water connection diagram on page 36 of the owner's guide).

A continuous dribble of water

Try gently raising the easing lever on the relief valve for a few seconds. This may dislodge a small particle of foreign matter and clear the fault. Release the lever gently.

Steady flow for a long period of time (often at night)

This may indicate the mains water pressure sometimes rises above the designed pressure of the water heater. Ask your installing 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 from the temperature pressure relief valve until the water heater is cold - then stops until water reheats

The water heater must be switched off at the switchboard. Phone Rheem Service or their nearest Accredited Service Agent to arrange for an inspection.

Higher than expected electricity bills

Should you at any time, feel your electricity bill is higher than expected we suggest you check the following points:

Is the relief valve running excessively? Refer to“Temperature Pressure Relief Valve or expansion control valve running” on page 25 in the owner's guide.
Is one outlet (especially the shower) using more hot water than you think? Refer to “Not enough hot water“ on page 23 of the owner's guide.
Is there a leaking hot water pipe, dripping hot water tap, etc? Even a small leak will waste a surprising quantity of hot water and electricity. Replace faulty tap washers, and have a plumber rectify any leaking pipe work.
Has there been an increase in hot water usage? An increase in hot water usage will result in an increase in water heater operation.
Has your water heating tariff rate been increased by your electricity retailer since your previous bill?

Electricity tariff changes

The electricity tariff to which your water heater is connected will determine the overall operating cost of the system. It is important you are aware of this tariff.

If you have checked these troubleshooting tips and still need assistance, contact Everyday Plumbing and Gas we service Sydney, Sutherland Shire, Canterbury Bankstown, Liverpool, and St George areas at 1300 400 200.

Reference - https://www.rheem.com.au/rheem/help#guides