Your cylinder may just need a repair, not a replacement.
Does your hot water cylinder suffer from one of the following conditions?

• No Hot Water
• Very Low Temperature
• Knocking (Banging) Noises
• Hot Water Smells
• Low Pressure
• Leaking Hot Water Cylinder
• Damaged Hot Water Cylinder
• Discharge Valves Running Constantly

First things first, DON’T PANIC!

Your hot water cylinder may be repairable.

Hot Water Cylinders NZ provide unique repair options for most hot water cylinder related faults. Before jumping into an expensive replacement, get the professionals in to investigate and repair the problem at a fraction of the cost.

Hot Water Cylinder Faults and Remedies

NO HOT WATER (Temperature)

Possible Faults: Faulty thermostat, faulty element, blown fuse, power provider ripple control.

Possible Remedies:  Replace thermostat, replace element, replace fuse, unsubscribe, ripple control.

NO HOT WATER (Physically)

Possible Faults: Blocked tempering valve, blocked strainer, incoming water problem, various possible blockages, damaged valve.

Possible Remedies: Process of elimination, identify fault and repair.

VERY LOW TEMPERATURE (or High/Low Fluctuation)

Possible Faults: if applicable, incorrect controller or thermostat settings, damaged element, damaged or wrongly set tempering valve, damaged diffuser, possible blockages, tapware problem.

Possible Remedies: Change thermostat and/or controller, tempering valve settings. Process of elimination, identify fault and repair.

KNOCKING OR BANGING NOISE (Water Hammer)

Possible Faults: This fault can appear when upgrading from low to mains pressure. Existing pipework not fixed properly, plumbing priority wrong, too much pressure, damaged valves, damaged or unsuitable tapware.

Possible Remedies: Find and fix loose pipework, improve existing priority, install water hammer arrestor. (For more information please view our “what is water hammer” blog.)

HOT WATER SMELLS BAD

Possible Faults: (External Smell) Typically an issue that relates to older cylinders or cylinders that have been slowly leaking internally (element thread or minor crack) for longer periods of time. When the insulation between the casing and tank is wet for a long period of time, it will rot and start to smell. (Internal Smell) A bad smell coming from the tap when hot water is running may be caused by the following: Bacterial growth due to minimum HWC temperatures not being met, accumulated sludge/rust caused by insufficient protection against electrolysis(?) due to the breakdown of a sacrificial anode. Incoming water affected by filthy water tanks or non-treated roof water. Note that smell is heightened by the higher water temperature.

Possible Remedies: Replace hot water cylinder, process of elimination, identify fault and repair.

LOW PRESSURE

Possible Faults: This fault will depend on whether it’s an existing low pressure problem or whether it’s a new low pressure problem. (Existing) Existing low pressure system and no fault, damaged pressure reducing valve, incoming pressure changes, tapware, related valve issue, excessive sludge/debris blocking outlet. (New) Tapware, blockages, valves, incoming pressure.

Possible Remedies: (Existing) Replace/repair valves/tapware, remove blockages, insert booster pump, upgrade to mains pressure. (New) Replace/repair valves/tapware, remove blockages. Process of elimination, identify fault and repair.

LEAKING HOT WATER CYLINDER

Possible Faults: Split welded seams or welded connections caused by various reasons including thermal expansion and contraction, typically seen with older leaking hot water cylinders, loose fitting, damaged fitting/valve, overheating causing condensation, worn element washer.

Possible Remedies: Repair leak where possible, hot water cylinder replacement.

DISCHARGE VALVES RUNNING CONSTANTLY

Possible Faults: In most cases there is no fault at all. The cold water expansion valve (considered the energy valve) may discharge up to 20L/day in very hot weather and no hot water usage. The idea is to discharge cold water instead of hot water to save on power which is much more expensive than water. Faulty valve, faulty TPR, debris blocking valve spring.

Possible Remedies: Follow manufacturing instructions to manually discharge water from valve to remove debris, regularly maintain valves, repair or replace faulty valves.

In some cases a repair is not possible or recommended, especially if it’s not economical or safe to do a repair. Depending on the fault, our team is trained to make the recommendation that will assist you with your budget and requirements.

WARNING!! When older cylinders are repaired or an element is replaced, they must be drained to enable the process of repair. This draining will cool down the cylinder tank and reduce its pressure. Consequently higher expansion and contraction will take place when the cylinder is re-pressurised (refilled with water). This process may result in an already poorly welded tank seam cracking which would result in a leak. The danger is that a seam cannot be repaired and a full cylinder replacement would be required, rendering the original repair redundant.

This information may be updated regularly to accommodate new information. 

Do you hear banging or knocking coming from your water system? Often times we get people reporting a banging noise coming from the water system, but there is nothing hitting any of the pipes or parts. This phenomenon is called Water Hammer. How is this caused?

Water hammer is caused when the valves are shut off, and the sudden stoppage of the water causes a sudden spike in pressure which reverberates through the pipes, causing them to rattle and shake, and produce the knocking noise. Areas that commonly have water hammer issues include:

• Flush valves
• Solenoid valves (washing machines, dishwashers and zip boiling units)
• Ceramic disc tap ware
• Full flow ballcocks
• Long runs of pipe
• Pumps
• Worn out valves

What can you do to stop this noise? The solution to this comes by means of a device knows as a Water Hammer Arrestor. What this device does is it provides a comprehensible cushion of air in the system, so when pressure occurs the water is pushed against this air which absorbs this spike. You want this placed as close as possible to the offending valve, pipe or area where the banging is occurring. Depending on the pipework system and how extensive it is, you may need to use multiple arrestors to effectively solve this situation.

Types of water hammer arrestors

Single Chamber Water Hammer Arrestor – A commonly used arrestor, these are most often used on 12mm pipe and are easily installed onto any section of pipe where it is needed. Its sealed air chamber absorbs the energy from pressure spikes in the water pipe system. These arrestors are made of copper and sustain water temperatures up to 80ºC. The benefit of these arrestors are that they can be installed at any angle to the main pipe. If a threaded joint is not available to attach the arrestor, it can be soldered into place on a T-joint and fitted into the existing pipe, taking up little space behind the wall panel.

Mini End Stop Water Hammer Arrestor – This type of water hammer arrestor is designed to be directly attached to the hose connection of a washing machine, dishwasher, or other water-using appliance. It comes with a 90-degree angled fitting and a threaded end and can be used on a range of pipes from 12mm to 25mm. They can be screwed to a threaded fitting or soldered directly into the pipe itself. While they work best installed at 90 degrees, they work at any angle. Like the single chamber arrestors, these only need minimal space behind any interior wall.

Hose Bib Style Water Hammer Arrestor – These are ideally suited to be used directly on the water intake on washing machines, as they can handle higher water volumes pressures than the other types. These have a wide PVC housing with an internal diaphragm to disperse the shock of water flowing through a quick closing valve. They are larger in diameter and therefore not suited for installation inside a wall. They also tend to be the most expensive to purchase and install.

To read more about RMC water hammer arrestors see the following:

RMC – What Is A Water Hammer?

Water Hammer Faults And Remedies

If you try to save power by reducing your hot water cylinder temperature, you need to be very careful. The following may also happen to you:

https://www.stuff.co.nz/national/health/96161836/water-cylinder-warning-after-nelson-bays-family-develops-rash-after-showering

Cases of Legionella have been popping up as people have fiddled with their hot water cylinders, lowering the temperature in an attempt to save on heating costs. But this can cause a serious problem.

Hot water cylinders should normally be set to a minimum 60°C. At this temperature, bacteria cannot survive, and therefore keeps your water clean. When you set the temperature lower than this, it becomes an optimal breeding ground for Legionella bacteria, which is the main concern for hot water systems in New Zealand.

Some people, however, think that by lowering the temperature that the hot water cylinder is set at, they will save power. While this can work, going below 60°C is not safe, because this is the perfect  temperature range for the bacteria to grow.

What is Legionella?
Legionella is an aquatic bacteria that lives in warm water conditions. It is the cause of Legionnaires disease and is commonly found in potable water supplies, hot tubs, cooling towers, fountains, swimming pools and so on. It breeds in warm water temperatures of 20-45°C. This is why it is recommended to keep your cylinder above 60°C, they cannot survive at these temperatures.

Most cylinder manufactures these days such as Rheem have a prevention lock on the thermostat which restricts people from reducing the temperature via the thermostat. In most cases, it is only possible with older models, however we have come across several systems where DIYers have dropped the temperature through various methods despite the thermostat lock by manipulating components. This results in damage and invalidation of warranties.

If you are looking for ways to save on water heating, speak to us today about upgrading to a more efficient hot water system. Don’t risk your health to save a few dollars!