Hot Water Service Maintenance To Extend The Life Of Your Hot Water Heater

You Can Increase the Lifespan of Your Hot Water System With a Few Simple Measures

 

We have all heard the saying prevention is better than cure. In the case of a hot water heater, this is certainly true. Let’s face it most would agree waking up to a cold shower in the middle of winter is not a pleasant experience.  

An efficient, well maintained hot water service is essential in reducing your energy costs. Around 27% of the electricity used in the average Queensland household is for heating water, making the hot water service one of the highest single energy users in the home. The average lifespan of a water heater is 7 to 16 years so just like the servicing of a car it makes sense to keep your hot water tank well maintained.

 

Pressure Relief Valve

What does the Pressure Relief Valve do?  
When a hot water service is heating the water steam is created which in turn increases the pressure inside the tank. The pressure relief valve is the safety device that allows that steam to escape. This is why you will see water dripping from this valve after you have used hot water.

Where is the Pressure Relief Valve located?
The valve is generally located near the top of the water heater at the same level as the hot water outlet pipe.

How often should the Pressure Relief Valve be serviced?
As this is a safety mechanism we recommend checking its operation on a quarterly basis.

With many hot water heaters installed outside you need to check that the valve has not become blocked by ants, hornets or other creatures. An easy way to remind yourself that it is due is to schedule the check when you receive your quarterly electricity account.

Pressure Relief Valve Service Instructions
To check the correct operation of the relief valve on your hot water heater lift the lever on the relief valve until a steady stream of water flows. If the flow is steady and stops once the lever is released when the valve is functioning correctly.

If however, no water comes out or it continues to leak after you have released the valve then it is likely that it needs replacement. Difficulty in moving the lever due to mineral build up or leakage of more than 1 litre per 50 litre of capacity in any 24 hour period is also good reason to replace this part of the hot water heater.

 

Cold Water Expansion Valve

What does the Cold Water Expansion Valve do?   
As with the relief valve a cold water expansion valve is used to release pressure as the water in the hot water service is heated.

The pressure setting on a cold water expansion valve is lower than that of the relief valve so it will start to release water earlier than a relief valve. As the water released from this valve is cold, energy is conserved.

Where is the Cold Pressure Relief Valve located?  
The valve is installed on the cold water inlet line, downstream from the isolation valve to the hot water heater.

How often should it be serviced?
As with the pressure relief valve we recommend flushing the valve on a quarterly basis. With many hot water heaters installed outside you need to check that the valve has not become blocked with foreign bodies. An easy way to remind yourself that it is due is to schedule the check when you receive your quarterly electricity account.

Cold Pressure Relief Valve Service Instructions
To check the correct operation of the cold water expansion valve on your hot water heater, lift the lever on the valve until a steady stream of water flows.

If the flow is steady and stops once the lever is released when the valve is functioning correctly. If however, no water comes out or it continues to leak after you have released the valve then it is likely that it needs replacement.

Difficulty in moving the lever due to mineral build up or constant leakage from the valve is also a good reason to replace this part of the hot water heater.

 


Tempering Valve

What does the Tempering Valve do?   
Tempering valves are designed to blend hot and cold water to deliver mixed water at a constant temperature that does not exceed 50°C.

The internal mechanism of the valve has a temperature sensitive element that expands and contracts depending on the temperature of the water flowing across it.

This, in turn, moves a piston between the hot and cold ports thus regulating the water to maintain a constant outlet temperature and reduce the risk of scalding accidents.

Tempering valves come in a range of models, from standard to high performance, to suit all types of water heater installations.

Where is the Tempering Valve located?
In older homes that only have a single water line from the tank to deliver hot water, you will typically find the tempering valve fitted at the hot water service in a connection between the cold water inlet and hot water outlet of the hot water heater.

The valve allows the water to mix and then leaves the valve in a common line to deliver tempered water to the house.  In more recently built homes a non-tempered line generally supplies the kitchen sink and laundry with the bathrooms supplied by a tempered line as above.

Occasionally you will find that tempering valves are fitted at each of the plumbing fixtures in the bathrooms however this is far less common.

How often should a Tempering Valve be serviced?
All valves associated with hot water are subject to operating extremes and for this reason require periodic maintenance, servicing and in some instances replacement.

A tempering valve is at the upper end of risk assessment and for this reason, requires regular testing and maintenance as per the requirements of AS 4032.3-2004 which states that frequency of field tests are not to exceed 12 months.

Tempering Valve Service Instructions
Testing, servicing and routine maintenance of temperature control valves as per AS 4032.3 can only be carried out by suitably licensed technicians at intervals not exceeding 12 months. It is, however, the property owner’s responsibility to ensure that routine maintenance is carried out.

 

Pressure Limiting Valve

What does a Pressure Limiting Valve do?  
A pressure limiting valve is a device that is ideal to be retro fitted to households that do not have a pressure reduction valve installed at the meter on the property boundary.

It is used to control the cold water supply to the hot water heater to a pre-set maximum pressure and in doing so prevents damage from an overpressure condition within the heater.

Where is the Pressure Limiting Valve located?
Installation of a pressure limiting valve is undertaken downstream of the isolation non-return that can be found fitted to the cold inlet side at the bottom of the hot water service.

They come in a range of models with outlet pressure settings of 350kPa, 500kP, and 600kPa. Water to the hot water heater should not exceed 500kPa.

How often should it be serviced?
Pressure limiting valves are manufactured with inbuilt strainers to prevent damage to the valve from debris in the water supply. Whilst there is no set interval at which servicing is required we would recommend having this completed at the same time as your annual test and service of the hot water service tempering valve.

Pressure Limiting Valve Service Instructions
Servicing and maintenance can only be carried out by qualified and licensed persons. If you experience a drop in hot water pressure then you will need to call (07) 5580 4311 to schedule a service call to diagnose the fault.

 

Isolation Non-Return Valve

What does an Isolation Non-Return Valve do?
Installation of a Non-Return Isolation valve is required by the Australian National Plumbing Code on all pressurised water heaters.

The isolating valve provides a shutoff point that enables the hot water to be turned off in an emergency situation and still leave cold water to the house.

The non- return feature of the valve prevents loss of water that has already been heated thus saving energy and protects the mains water supply from backflow and possible contamination from the water stored in the water heater.

Where is the Isolation Non-Return Valve located?
An isolation non-return valve can be found on the cold water inlet supply to the hot water service that is located at the bottom of the water heater and will be the first valve on this pipeline.

How often should it be serviced?
An isolation valve is generally trouble free for the life of the tank as it seldom needs to be turned off. We would, however, recommend checking the valve once a year to ensure it is functioning correctly.

Non-Return Valve Service Instructions
Locate the isolation valve on the inlet water supply. Generally, it can be identified as the valve that has the large black plastic knob on top.

Turn the knob in a clockwise direction until it is screwed all the way in.

If the valve is functioning correctly no water will come out of any hot tap inside until you turn the valve back on. Once the test is complete turn the knob in the opposite direction (anti-clockwise) until it is completely open.

We would recommend checking the valve annually when the tempering valve is serviced however if you wish to undertake this check yourself then carry out with your three monthly check of the relief and cold water expansion valves.

 

Sacrificial Anode

What does a Sacrificial Anode do?
The sacrificial anode is a rod manufactured from magnesium formed around a steel core wire that runs down the centre of the hot water storage tank.

The purpose of the rod is to protect the tank from corrosion.

When metal surfaces come into contact with electrolytes, which are found in water, they undergo an electrochemical reaction known as corrosion.

Corrosion is the process of returning a metal to its natural state as an ore and in this process, causes the metal to disintegrate and its structure to grow weak.  

Magnesium has a more negative electrochemical potential than the metal used to manufacture the tank and will, therefore, be consumed in place of the metal it is protecting.

Where is the Sacrificial Anode located?
The sacrificial anode runs down the centre of the tank and is anchored by screwing into the top.

How often should the Sacrifical Anode be serviced?
Under normal conditions, the water heater anode will be consumed in four to five years, at which time the metal tank will start to corrode.

It is for this reason that we recommend replacement at four to four and a half years from installation. Areas, where the mineral content in the water is high, may need to have the anode changed earlier.

Sacrifical Anode Service Instructions
We would recommend only having this undertaken by a suitably qualified person and at the same time take the opportunity to have the tank flushed out to remove any debris that has settled in the bottom.

These two simple measures will add years to the life of your hot water heater. Call (07) 5580 4311 to schedule a Service Call.

 

Element

What does an Element do?
The hot water heater element is the mechanism that heats the water. It works in much the same way as an element in a kettle however in this instant the heating cycle is regulated by the thermostat.

The recovery rate (how quickly the element reheats the water) is determined by the wattage of the element, ranging from 1.8kw to 4.8kw.

The higher the wattage the quicker recovery time, however, the size of the element will be determined by the amount of water it needs to heat and the rating of the electrical wiring within the house.

Where is the Element located?
The element is located in the bottom of the hot water tank and is accessed through the small electrical box at the base of the tank.
As hot water is drawn off the temperature of the water inside the tank will drop.

Once it drops below the setting of the thermostat the element is activated to heat the cold water entering the tank. Dual element models have a second element located in the top third of the tank that is connected to the standard electricity tariff.

This allows for heating of the water at the top of the tank on hot water units connected to night rate electricity in the event of exhausting the available hot water.

How often should it be serviced?
The element on a hot water heater does not require any regular servicing and will only need attention should it fail.

Element Service Instructions
Water and electricity are a lethal combination and all servicing should be undertaken by suitably qualified people.

Call (07) 5580 4311 to schedule a call.

 

Thermostat

What does a Thermostat do?
The thermostat is the mechanism that controls the temperature of the water within the hot water service. Whenever the temperature of the water drops below the thermostat setting then the element is activated to reheat the water.

To prevent the development of Legionella the thermostat should be set to heat the water stored in the tank to a temperature of 60’ or higher.

Where is the Thermostat located?
The thermostat is located in the small electrical box at the side of the hot water service at the base of the tank.

How often should it be serviced?
As with the element the thermostat does not require servicing and will only need replacing should it fail. It is fitted with a reset button to protect it from overheating so if you have no hot water you may like to check this prior to calling a service technician.

Thermostat Service Instructions
Before you do anything isolate the power to the complete house at the meter board.

Remove the screws and cover plate over the electrical box. Check if reset button has activated, if so push back in. Replace cover and screws before turning the power back on.

Replacement of the thermostat will be required if you get repeated tripping of the reset button. Call (07) 5580 4311 to schedule a call.