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Hot Water System

The following topics are discussed below:

  • Common Hot water system maintenance jobs:
    • Temperature pressure relief valve
    • Cold water expansion valve
    • Thermostat
    • Element
    • Anode
    • Leaking hot water cylinder
    • Discoloured hot water
    • Low hot water pressure
    • Hot water too hot
    • Hot water too cold
    • Tempering valve issues
    • Water hammer
    • CURRENT SPECIAL OFFERS

 

Introduction

We use hot water for shower, basins, cleaning our dishes, cleaning our clothes, yet we never really think about where this hot water comes from until something takes the hot water away.

Australian Hot water systems are well made and do stand the test of time for the most part, but hot water system components are not made to last forever and will start failing when you least expect it.

 

Temperature pressure relief valve

Where – This valve is located at the top of the hot water system next to the hot water outlet. It should have a copper pipe attached to the bottom of the valve which runs to the ground or a drain.

Common Problems

  • The most obvious and common problem is when the valve leaks water. It is designed to leak a small amount of water to relieve the pressure in the tank. If the valve leaks all the time, even just a fast drip, then the valve is faulty.
  • The next problem and the most dangerous is when the valve doesn’t relieve pressure at all. Every 3 months, you need to pull the valve lever to see if it is working. If no hot water comes from the hot water system, then call a plumber asap.

 

The cold water expansion valve

Where – This valve looks like the temperature pressure relief valve but is located near the bottom of the hot water system near the water inlet. It is designed to relieve pressure from the hot water system from the cold-water entry into the tank.

Common Problems

  • The most obvious and common problem is when the valve leaks water. It is designed to leak a small amount of water to relieve the pressure in the tank from the cold side of the drain. If the valve leaks all the time, even just a fast drip, then the valve is faulty.
  • The next problem and the most dangerous is when the valve doesn’t relieve pressure at all. Every 3 months, you need to pull the valve lever to see if it is working. If no hot water comes from the hot water system, then call a plumber asap.

 

Thermostat

Where – This device is located just inside the control panel at the bottom of your hot water system. This is only to be accessed by a qualified person.

Common Problem

  • The hot water is not hot enough or it is too hot. The thermostat either needs the dial settings changed or the thermostat may need changing. Either way, a qualified person needs to do this job to avoid serious injury.

 

Element

Where – The heating element is positioned inside the control panel at the bottom of the hot water system. It is bolted to the hot water system so that the wiring on the outside heats up the element on the inside of the tank.

Common Problems

  • Power Surge – burns out the element
  • Scale build up
  • Wiring problem
  • Split element
  • Vibration Break

In each of these cases, the most viable option is to change over the element for a new one. Your qualified tradesman will be able to do this and advise you on what the cause of the problem was. If the thermostat is of a similar age as the element, I would advise changing this over at the same time. This will save you about $120- $150 in the long run.

While the element is out, it would be an ideal time to flush out the hot water system. This will help prolong the life of the tank and its components.

 

Anode

WhereAt the top of the tank, underneath the circle cap.

The anode prolongs the life of your hot water system cylinder by reducing internal corrosion.

This needs to be replaced every 5 years or so, depending on the PH and conditions of the water. This needs to be done by a plumber as it involves opening the hot water system which could be dangerous unless you know what you are doing.

 

Leaking hot water cylinder

Common areas  of failure

 

> The element is sealed by a rubber which over time has a habit of perishing. When this happens, the whole element has to be pulled out and replaced with a new one. When this is done, ask the plumber to check to see how well the element is performing. It may be wise to just change over the element at this point too.

 

> Corroded tank. With time, the tank will naturally corrode. The best way to extend the tanks life is to replace the anode every 5 years. Again, if you have a plumber over after 3-4 years for another job, just get them to throw in a new anode.

 

> Poor workmanship. Screws are quite often the cause of tank leaks. It is unwise to screw into the tank. If you need to, check the manufacturer’s specifications first to see how thick the insulation is.

 

> Hot water system installed on the incorrect base. A hot water system needs a solid base, installed above the surrounding ground which allows air to flow underneath. If your hot water system is not raised, it is prone to corrosion from water and moisture below. A poor base set up rusts the hot water system out very fast.

 

Discoloured Hot Water

Where – From the hot water outlet

Sometimes, when you leave the water tank and water service to settle for a week or two. When you return, the water comes out with light colour brown.

If you let the water run from hot and cold outlets for 5 mins straight, this will normally sort out the problem within a short time. If you have an old tank and old water pipes, this may only be for a very short time.

Firstly, flush out the hot water system until the inside of the tank is clean. If this still doesn’t fix the problem, then the old pipes may need to be changed. If you have galvanised pipes, I would recommend changing them anyway.

 

Where – This is very common. No internal hot water outlet is exempted from this happening although it probably happens more where there are mixer taps with a spout.

 

This happens not because of the hot water system but because of the components attached to the hot water system

 

> the tempering valve sometimes gets grit in its strainer which causes a pressure drop. The strainer needs to be cleaned.

> the tap aerators have grit in their strainers

 

Hot water too hot

Where – Hot outlets

The tempering valve needs to be adjusted or replaced. If the house doesn’t have a tempering valve because house predates this rule and only has a thermostat, turn the thermostat down to 61 degrees, anything lower than 60 degrees will make your hot water system susceptible to Legionnaires.

 

Hot water  not hot enough

Where – Hot outlets

The tempering valve needs to be adjusted or replaced.

Tempering valve issues

Where – The tempering valve will most likely be situated near your hot water system. It will be silver in colour and have the hot water entering one side of the valve and cold water entering the other side of the valve, the tempered water mixes, and exits in the middle of the valve.

Common Problems

  • Incorrectly adjusted to produce either water which is too hot or too cold.
  • Incorrectly installed so that the hot side is fed by the cold water and cold side is fed by the hot water. This normally produces hot water with no adjustment.
  • Low pressure – The tempering valve strainer has grit blocking the water flow and needs to be cleaned to increase flow.

 

Future Projects

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Current special offers

  • We will Install your storage hot water system for $350 (External)

(Materials not included)