Hot Water Cylinder Replacement

Hot water cylinders are the most commonly used hot water heating systems in New Zealand and can last a long time if properly maintained. The time may come to upgrade your system if your cylinder has broken down or starts to leak, based on your hot water needs you may choose to replace your current model with a similar one or you may choose to upgrade to a bigger capacity model to suit your needs. Regardless, it can be a stressful time if your old model is no longer working and you’re stuck without hot water. You will need to be informed and you may require expert advice to make the right decision under the time constraints. 

How much to replace hot water cylinder?

Trade up and trade in your old low pressure cylinder with a new 180 ltr mains pressure cylinder  for only $2400 + GST (standard installation, electrician not included)

Signs that your hot water cylinder may not be functioning properly anymore include

  • No hot water
  • Low water temperature
  • Knocking or banging noises
  • Hot water smells
  • Low water pressure
  • Leaking hot water cylinder
  • Damaged hot water cylinders
  • The discharge valves running constantly

In certain cases, you may be able to repair your hot water cylinder instead of replacing it. By investigation and process of elimination, Sumich Plumbing can identify the issue and repair the fault.

If you have flowing water, but it is not coming to temperature you may have

  • A faulty thermostat or element
  • A blown fuse or power provider ripple control.

This can easily be remedied by replacing the thermostat, element or fuse.

If you do not have flowing hot water, the issue may lie with

  • A blocked tempering valve or strainer
  • Incoming water problem
  • Various possible blockages
  • A damaged valve.  

If you have very low temperature or water temperature fluctuations, possible faults include

  • Incorrect controller or thermostat settings
  • A damaged element
  • A damaged or incorrectly set tempering valve
  • A damaged diffuse
  • A possible blockage
  • A tapware issue.

To remedy this, you may need to change the thermostat, controller or tempering valve settings.  

If you hear a knocking or banging noise, this can be caused

  • By upgrading from a low-pressure system to a mains pressure system.
  • The existing pipe work may not be fixed properly
  • The plumbing could be prioritised incorrectly
  • There could be too much pressure
  • The valves could be damaged or unsuitable.

To stop this from happening, you can find and fix the pipe work; improve the existing priority; or install a water hammer arrestor. 

Smelly hot water can be caused by

  • Bacterial growth due to the water temperature not meeting minimum HWC temperatures.
  • It can also be due to accumulated sludge or rust caused by insufficient protection against electrolysis as the anode rod breaks down.
  • If the smell comes from the hot water cylinder itself, it is typically caused by older cylinders or cylinders that have been slowly leaking over an extended period of time, due to a threaded element or a minor crack.

The only possible outcome may be to replace the hot water cylinder as the issues can be too severe to remedy.

Low water pressure may be an existing or a new problem. An existing low water pressure issue may be caused by

  • A damaged pressure reducing valve
  • Incoming pressure changes
  • Tapware or related valve issue
  • Excessive sludge or debris blocking the outlet

New low water pressure issues can be caused by

  • Faults or blockages with the taps and valves,
  • Issue with the incoming pressure.

Leaking hot water cylinders can be caused by a range faults, these include

  • Loose connections
  • A faulty element washer
  • A faulty valve
  • Excessive pressure
  • Thermal expansion or contraction
  • A cracked tank. Usually a cracked tank is cause by excessive pressure, overheating or old age.

Sumich Plumbing will be able to repair the leak but replacing the unit could be more successful remedy. 

If the discharge valves are running constantly

It could indicate the valve may be faulty or debris are blocking the valve spring. To remedy the problem, you can attempt to discharge water from the valve to dislodge debris by following the manufacturer’s instructions. You should also maintain the valves regularly and repairing or replace any faulty valves. 

Your decision to repair or to replace the hot water cylinder has to be considered carefully and should start with the age of your cylinder. A traditional hot water cylinder can last anywhere between eight to twelve years, if your cylinder is at the end of this range you may consider replacing it.

Discoloured or Rust Coloured Water

Hot water cylinders have an anode rod inside to help protect the interior lining by attracting corrosive particles by electrolysis. As time goes on, the rod can corrode preventing it from functioning properly. At this stage, the inside of the tank will start corroding, this will signal the end of the hot water cylinder’s life span. Signs that this may be happening include discoloured or rust-coloured water and a metallic taste to the water. 

You may choose to replace your current hot water cylinder with a similar model, that could be a low pressure hot water cylinder or a mains pressure hot water cylinder. Or you could take the opportunity to upgrade your hot water system to a different type that is more suited to your hot water needs, alternative options include gas continuous flow hot water system, a hot water heat pump system or a solar water heating system. Your decision may largely be based on the cost of installation and ongoing running costs. Installing a new hot water cylinder can cost anywhere between $2,000 and $3,000, the running costs for the average three-person household are approximately $560 to $1,000 a year. 

If you are located in Auckland contact Sumich Plumbing to find out how much it will cost for hot water cylinder replacement.

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