How to Fix the 5 Most Common Electric Storage Water Heater Problems

Electric storage water heaters are essential appliances in many homes, providing hot water for daily showers. However, they can sometimes encounter issues that disrupt their functionality. This article will guide you through fixing the five most common problems with electric storage water heaters: electric power tripping, water leaking from the tank, inconsistent temperature, low water pressure, and a pressure relief valve that keeps releasing water.

1. Electric Power Tripping

Possible Causes:

1. Faulty Heating Element: Over time, the insulating material around the heating element can degrade due to heat and water exposure. This degradation can lead to the metal part of the element coming into direct contact with water, causing a short circuit.

Solution: Test the Heating Element using a multi-metre for continuity and to check for a short to ground. Place one probe on the terminal and the other on the metal part of the heating element. If there is continuity, the element is shorted and needs to be replaced.

2. Thermostat Malfunction: If the thermostat fails to properly regulate the temperature, it may cause the heating elements to remain powered on continuously. This can lead to overheating and potentially damage the heating elements’ insulation, which can then result in a short circuit.

Solution: Same as above. The thermostat will have to be changed along with the heating element.

3. Worn out Heater Switch: The internal components of a heater switch can wear out or become faulty, leading to a short circuit. This includes the contacts, springs, and other mechanical parts.

Solution: Replace with High-Quality Switches that is double pole, 20A and Safety Mark certified by an EMA LEW or trained technician supervised by an EMA LEW.

4. Loose Wires Connections: Loose connections at the connection box can cause the electrical current to arc or create resistance, generating excessive heat and leading to wire burnout. Burning out will reduce the insulation resulting in short circuit.

Solution: This is usually due to poor Installation: If the wires were not securely tightened during installation, they may become loose over time. Get an EMA Licensed Electrical Worker (LEW) to carry out the job or a trained technician supervised by an EMA LEW.

5. Overloading the Circuit: The same circuit may be used for multiple high-power appliances, exceeding its 20A capacity. For example, a Dyson hair dryer (1,500W) and a Philips Iron steamer (2,000W) taping into the circuit with a Rheem EHG30 (3,000W). The combination will result in 28A exceeding the MCB rating of 20A.

Solution: Strictly adhering to SS 638_2018 Code of Practice for Electrical Installations, Electric storage heaters must be connected to a dedicated circuit. This circuit is intended to handle the specific electrical load of the heater without sharing it with other appliances.

6. Undersized electrical cables: Using cables not approved for use in Singapore or those with nominal area of less than 2.5mm2 (7 strand/0.67mm diameter). We saw many burnt out happened when 1.5mm2 nominal area is used or even 3 Core 3C x 70/0.0076 inch, a specification found in Malaysia.

If the above checks are all negative, then a thorough check earth leakage is required either:

To do a Simple visual inspection and Repair Wiring: Check the wiring for any signs of damage or wear. Repair or replace faulty wiring.

Or

Conduct testing in accordance with section 612 Testing of Singapore Standard Code of practice for electrical installations SS 638: 2018

612.1 General

Measuring instruments and monitoring equipment and methods shall be chosen in accordance with the relevant parts of IEC 61557 series.

To comply, use a tester like for example KYORITSU ELECTRICAL INSTRUMENTS WORKS, LTD, KEW 601OB. Here are the relevant parts:

• IEC 61557-1: General requirements – This part specifies the general requirements applicable to the whole series of IEC 61557. It includes definitions, requirements for accuracy, and other essential criteria.
• IEC 61557-2: Insulation resistance – This part covers equipment used for measuring the insulation resistance of equipment and installations.
• IEC 61557-3: Loop impedance – This part specifies the requirements for instruments used to measure the loop impedance to verify the effectiveness of protective measures.
• IEC 61557-4: Resistance of earth connection and equipotential bonding – This part deals with measuring the resistance of earth connections and equipotential bonding to ensure proper grounding and safety.
• IEC 61557-5: Resistance to earth – This part covers equipment used to measure the resistance to earth to ensure the effectiveness of grounding systems.
• IEC 61557-6: Effectiveness of residual current devices (RCD) in TT, TN, and IT systems – This part specifies requirements for equipment used to test the effectiveness of residual current devices.
• IEC 61557-7: Phase sequence – This part addresses the requirements for instruments that verify the phase sequence in three-phase systems.
• IEC 61557-8: Insulation monitoring devices for IT systems – This part covers devices that monitor the insulation resistance of IT (isolated) systems.

612.3.1

The insulation resistance shall be measured between live conductors and between live conductors and the protective conductor connected to the earthing arrangement. Where appropriate during this measurement, line and neutral conductors may be connected together.

Measurement of insulation resistance between the neutral and earth conductors. Reading being 0L (over the limit, limit being 200MΩ), passed. See table 61, minimum resistance required is 1MΩ.

612.3.2L

The insulation resistance measured with the test voltages indicated in Table 61 shall be considered satisfactory if the main switchboard and each distribution circuit tested separately, with all its final circuits connected but with current-using equipment disconnected, has an insulation resistance not less than the appropriate value given in Table 61.

Measurements shall be carried out with direct current. The testing apparatus shall be capable of supplying the test voltage indicated in Table 61 when loaded with 1 mA.

NOTE – More stringent requirements are applicable for the wiring of fire detection and fire alarm systems in buildings, see SS CP 10.

Table 61 shall be applied when verifying insulation resistance between non-earthed protective conductors and earth.

To comply with 612.3.1 and 612.3.2L, the test value shall be minimum of 1MΩ. Very frequently, a 0L (over the limit, limit being 200MΩ) will show.

2. Leaking Water from the Tank

Possible Causes:

1. Loose fittings and pipework connections: Water connections might have become loose over time. Faulty Pressure Relief Valve: The valve could be malfunctioning, causing leaks. Corrosion: Corrosion inside the tank can lead to leaks.

Solutions:

Tighten Connections: Check all water connections and tighten any that are loose. Replace the Pressure Relief Valve: If the valve is leaking, replace it with a new one.   Inspect for Corrosion: If the tank is corroded, it will likely need to be replaced.

2. Inner tank broken

The breaking of a storage heater’s inner tank can be caused by several factors:

• Corrosion: Over time, the inner tank, typically made of mild steel, can corrode due to constant exposure to water, especially if the water is acidic or has high mineral content. Corrosion weakens the tank walls, making them more prone to rupture.
• Pressure Build-Up: Excessive pressure can build up inside the tank if the temperature and pressure relief valve (T&P valve) malfunctions or is blocked. This can cause the tank to expand and eventually rupture.
• Sediment Build-Up: Sediment and mineral deposits can accumulate at the bottom of the tank, leading to uneven heating and increased pressure on certain parts of the tank. This can cause localized weakening and potential rupture.
• Thermal Stress: Repeated heating and cooling cycles can cause thermal expansion and contraction, which can stress the tank material over time and lead to cracks or ruptures.
• Poor Manufacturing Quality: Defects in the tank material or welding during the manufacturing process can create weak points that are more susceptible to rupture under normal operating conditions.
• Overheating: If the thermostat or heating element malfunctions, it can cause the water to overheat, increasing pressure and the risk of rupture.
• Mechanical Damage: Physical damage to the tank during installation or maintenance can create weak spots that may rupture under pressure.

Solution:

The only option is to have the leaking tank replaced.

With regular maintenance, such as flushing the tank to remove sediment, checking the Pressure relief valve, can help mitigate these risks and prolong the lifespan of the storage heater.

However, the most crucial point is to ensure the installation is done by a PUB Licensed Plumber. Never allow an unlicensed handyman to perform the installation, as this may result in higher costs in the long run and pose significant safety risks, effectively turning your heater into a potential time bomb.

3. Temperature Inconsistent

Possible Causes:

Faulty Thermostat: The thermostat may not be accurately regulating the temperature.

Sediment Buildup: Sediment in the tank can cause inconsistent heating.

Malfunctioning Heating Elements: The heating elements might not be working properly.

Solutions:

Replace the Thermostat: If the thermostat is not functioning correctly, replace it.

Check and Replace Heating Elements: Inspect the heating elements and replace any that are not working.

4. Low Water Pressure

Possible Causes:

1. Corrosion of iron pipes leading to clogged water flow at the tank inlet and outlet that are made of galvanised iron.

Process of Corrosion and Clogging

• Initial Exposure:

Iron pipes are exposed to water and oxygen, the primary agents that initiate the corrosion process.

• Formation of Rust:

When iron (Fe) in the pipes comes into contact with water (H2O) and oxygen (O2), a chemical reaction occurs, forming iron oxide (Fe2O3), commonly known as rust.

• Build-up of Rust:

As rust forms, it starts to accumulate on the inner walls of the pipe. This build-up is not smooth; it is rough and flaky, creating a layer that gradually thickens over time.

• Reduction in Pipe Diameter:

The accumulating rust layer reduces the effective inner diameter of the pipe, restricting water flow. This is analogous to cholesterol build-up in arteries, which restricts blood flow.

• Release of Rust Particles:

Small rust particles can break off and move with the water flow. These particles can accumulate at bends, joints, or other constrictions within the plumbing system, contributing to further blockages.

• Impact of Water pH:

Acidic water (low pH) accelerates the corrosion process. Iron dissolves more readily in acidic conditions, increasing the rate at which rust forms.

• Ongoing Cycle:

As rust continues to form and build up, the flow of water is increasingly restricted. This can lead to reduced water pressure and eventually to complete blockages.

• Signs and Symptoms:

1. • Initially, you may notice discoloured water (brown or reddish) due to the presence of rust particles.
   • Over time, water flow diminishes, and water pressure drops significantly.
   • In severe cases, the pipe can become completely clogged, stopping water flow altogether.

Solution:

Typically, the cost of maintenance in Singapore is higher than to have the storage heater replaced, however, you may do the following if you have the resources.

• Regular Maintenance: Flushing the plumbing system regularly to remove loose rust particles can help.
• Cathodic Protection: Installing sacrificial anodes can help protect iron pipes from corrosion by redirecting the corrosive process to the anode instead of the pipe.

2. Broken gate valve shaft. A broken gate valve shaft can occur after turning off the valve, making it impossible to turn it back on and thus stopping the flow of water through the pipework.

• Excessive Force: Applying too much torque or force while opening or closing the valve can stress the shaft beyond its capacity, leading to breakage. This is common when operators use tools or excessive manual force.
• Corrosion: Over time, exposure to corrosive environments or substances can weaken the shaft. Corrosion can cause pitting, reducing the shaft’s structural integrity and making it more susceptible to breaking under normal operational forces.
• Material Fatigue: Repeated use of the valve over many years can cause material fatigue. The constant opening and closing cycles can create small cracks that grow over time, eventually leading to shaft failure.
• Improper Installation: Especially if carried out by an unlicensed handyman. If the valve was not properly aligned during installation, it can create uneven stress on the shaft when operated. Misalignment can cause the shaft to bend and break.
• Poor Quality Materials: Usually from sources that don’t comply with PUB’s Stipulation of Standards &Requirements for Water Fittings for Use in Potable Water Service Installations.

Shafts made from substandard materials or with manufacturing defects are more prone to breaking. Quality control issues during manufacturing can result in weak points in the shaft.

• Lack of Maintenance: Inadequate maintenance over the years can lead to the build-up of debris or corrosion that increases the operating force required, putting additional stress on the shaft. Regular lubrication and cleaning can prevent this.
• Mechanical Damage: External mechanical damage, such as impacts from tools or other equipment, can create weaknesses or cracks in the shaft, which can lead to breakage when the valve is operated.
• Improper Use: Using the valve in applications for which it is not designed, such as throttling flow instead of fully opening or closing, can put undue stress on the shaft and cause it to break.

Solutions:

This kind of work is regulated under the Public Utilities Act 2001.

Have the gate valve replaced in accordance with Water Supply Regulations which is enforced by PUB. A Licensed Plumber will need to submit a Certificate of Satisfactory Completion to PUB within 7 days upon completion of a regulated work.

5. Pressure Relief Valve Keeps Releasing Water

Possible Causes:

1. Excessive Pressure: The tank might be experiencing pressure higher than the setting to relief on the PRV.

In accordance with the Code of Practice for Water Services SS636: 2018

6.7 Distribution in Tall Buildings

• In tall buildings, fittings should not be subjected to pressures greater than 35 m head (50 psi). This can be achieved by the provision of intermediate tanks and pumps or using pressure reducing valves.

• The water pressure is controlled by the estate management in condominiums and by the town council in HDB estates. Sometimes, these managing parties can overlook the settings, causing the pressure to be set well above the 50 psi requirement. We have witnessed 116 psi at a condominium located in River Valley.
• The heater pressure relief valve (PRV) activation setting can range from 0.75 MPa (109 psi) to 1 MPa (150 psi).
• For a ballpark calculation of the pressure inside the tank after being fully heated, simply add 50 psi to the incoming water pressure, which is presumably 50 psi. Thus, the pressure in the tank at fully heated temperature would be 100 psi.
• This figure is still within the setting of most PRVs, which is 109 psi. However, if the incoming pressure increases, delivering beyond 109 psi, the PRV will activate to release the pressure by opening. The higher the pressure, the more frequently it will operate.
• In cases of excessive pressure, the PRV will remain open continuously.

Solution:

Write formally to the Town council (HDB) or to the management office of your condo in email cc to PUB informing them that allowing water pressure to your unit that is higher than the code of practice is a violation in Singapore.

Usually, it will take a few days for the management parties to send a licensed plumber to make the necessary adjustments.

A sample email:

Subject: Urgent: Water Pressure Violation and Request for Immediate Adjustment

Dear [Town Council/Management Office],

I hope this email finds you well.

I am writing to formally inform you that the water pressure supplied to my unit is currently exceeding the limits prescribed by the Code of Practice for Water Services SS636: 2018. Specifically, section 6.7 of the code stipulates that fittings in tall buildings should not be subjected to pressures greater than 35 m head (50 psi).

Recent measurements have indicated that the water pressure in my unit is significantly higher than this limit, reaching up to 116 psi. Such pressure levels pose a substantial risk to the integrity of the plumbing systems and appliances, particularly the storage heater, which is not designed to handle such high pressures. This excessive pressure violates the standards set forth in the Code of Practice and could potentially lead to serious safety hazards.

I request that a licensed plumber be dispatched to my unit as soon as possible to adjust the water pressure to comply with the stipulated 50 psi limit. Ensuring that the water pressure is within the safe and regulated range is crucial for the safety and longevity of the building’s water system.

For your reference, I have also copied this email to the Public Utilities Board (PUB) to keep them informed of this pressing issue.

Thank you for your immediate attention to this matter. I look forward to a swift resolution to ensure compliance with the Code of Practice and to safeguard the well-being of all residents.

Kind regards,

[Your Full Name]
[Your Unit Number]
[Your Contact Information]

2. Faulty Pressure Relief Valve discharging water continuously, indicating it may be stuck open can be due to several reasons

• Excessive Water Pressure: If the incoming water pressure is too high, it can cause the PRV to remain open to relieve the excess pressure continuously.
• Debris or Sediment: Accumulation of debris, sediment, or mineral deposits in the valve can prevent it from closing properly, leading to continuous discharge.
• Valve Wear and Tear: Over time, the internal components of the PRV can wear out or become damaged, preventing the valve from sealing correctly.
• Faulty Installation: If the PRV was not installed correctly, it might not function as intended, causing it to remain open.

Solutions:

Check Pressure Levels: Ensure that the pressure in the tank is within safe limits.   Replace the Pressure Relief Valve: If the valve is faulty, replace it with a new one.  Adjust Thermostat: Lower the thermostat setting to prevent overheating and excessive pressure.

Conclusion

Maintaining your electric storage water heater involves regular inspections and timely repairs. By addressing these common problems—electric power tripping, water leaking from the tank, inconsistent temperature, low water pressure, and a pressure relief valve that keeps releasing water—you can ensure a reliable supply of hot water in your home. It is crucial to engage only a licensed electrician for electrical works and a licensed plumber for plumbing works in Singapore. This ensures compliance with local regulations, enhances safety, and guarantees the quality of repairs. Proper maintenance and prompt repairs by licensed professionals will help extend the life of your water heater and keep it functioning efficiently. Licensed professional. Proper maintenance and prompt repairs will help extend the life of your water heater and keep it functioning efficiently.