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Gas Water Cylinders and Saftey

dux_hot_water_cylinderThis 1996 Dux Hardie (a james Hardie product) Vitreous Enamel gas hot water cylinder has had several repairs done over the years. Whether it was a failed gas thermocouple, replacing of a down-draft diverter or Piezo ignition device, we always pride ourselves in the ability of troubleshooting by following a simple process of elimination, identifying and fixing gas water heaters.

After a “smell of gas” was noticed, Hot Water Cylinders NZ were called to the scene to investigate and hopefully fix yet another possible fault. After only a few minutes onsite, our installers identified that an overheating issue had caused a “split in the seams” resulting in a drip onto the flame which evaporated, mimicking the smell of gas. This Natural Gas hot water cylinder was naturally redundant!

After a life span of 20 years the owners agreed it was time for a new and more efficient solution.

The first thing I noticed with these image was the quality and safety awareness of the installation itself. Unlike many older gas jobs we come across, no short cuts were taken and no safety measures were avoided which contributed to long life span and safe operation of this appliance on a property that has been purchased and sold over 8 times in the last 20 years.

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A quick look on the labels and manual show how important it is for the gas fitter to read and apply manufacturers instructions, these include:

  • For safe operation this water heater must be fitted with…1) Thermostatnatural_gas_cylinder
    2) Over-temperature control
    3) Combination pressure and temperature relief valve

Additional important points include how important it is to get your hot water cylinder serviced, ensuring valves are operating safely giving your hot water cylinder the best chance to provide you with hot water for many years to come.  Relief valves should be checked for adequate performance or replaced at intervals not exceeding 5 years or less in areas where local regulations apply.

With an appliance that includes an open flame (pilot light), safety must be recognized and followed to prevent harm to person and property. For instance, a gas hot water cylinder must be installed on a fire-proof base. The appliance should not be enclosed unless otherwise recommended by the manufacturer and sufficient ventilation has been provided. Operation should never take place with panels or covers removed and anything flammable should not be stored (prevented) in the vicinity of the appliance. It almost sounds like so much can go wrong, which could be true unless the installation company has enough experience to apply a “prevention” mentality which would eliminate all risks by simply following a code of standard.

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In this instance the owner of the property decided to switch to a tankless hot water solution. This meant reclaiming of their garage space and all the benefits that come with tankless water heating.

Being able to reuse the existing gas pipe meant savings on the installation. the only thing left was to remove the gas flue and repair the hole left in the roof. After 6 years of history with this appliance, it think deserves a special spot on our blog!

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10 Mistakes to avoid when buying a new Hot Water Cylinder

  1. Price Price Price
    Compare the price you have for one brand with another quality brand. Don’t be shy to ask for an alternate brand quote. Look at the differences and select the product that will most likely meet all your expectations now and in the future. This will also filter out those who are ‘partial to one brand’. They will always give you reasons as to why ‘their’ brand is better than the others.10_Mistakes_to_avoid_when_buying_a_new_Hot_Water_Cylinder
  2. Don’t Settle for Less.
    If you have to replace your existing hot water cylinder, make sure you get the most recent technology and quality. Many installers will try to flog off outdated stock and make it look like the deal of a lifetime. You will be surprised what modern specifications you are able to get for the same price without having to compromise on quality or warranty.
  3. Low VS Mains Pressure
    Let’s face it, with today’s technology, the world is going mains pressure. If you are replacing your low pressure cylinder, don’t let anyone tell you that you can’t replace it with a mains, because you have low pressure tapware. You can in fact upgrade to mains pressure and set your mains pressure system to accommodate your low pressure tapware. That way you have already future proofed for your upcoming new and amazing mains pressure tapware.
  4. Future Proofing
    This ties in nicely with point #1. Believe it or not a cylinder that is future proofed for solar, heat pumps and alternative energy will cost you the same as a cylinder that is not. With climate change and the costs of energy on the rise, you want to be ready for the next energy revolution which will involve having a cylinder that is also ready.
  5. Warranty
    Read the fine print! They say you get a 20 year warranty when in fact it’s conditional to a yearly service and expense, this should not be required at all, especially in the first 5 years. Seven to 10 years is a good indication of where a warranty needs to be here in New Zealand. Please note that parts subject to wear and tear are in most cases only covered by a one year warranty.
  6. Power Supply
    The trouble with cheap quotes is that they tend to leave out what They believe ‘you don’t need’ but will in-fact only benefit you in the long run. For example, this is the case with the power supply to your new hot water cylinder. If you are replacing an older hot water cylinder, your power switch will be of the same age and wont comply. If it’s round and in most cases black (Baker Light Power Switch), it must be replaced. These switches are deemed as unsafe (electrical hazard) by the electrical board of New Zealand because they can only support 10 AMPS (just below 2KW) and most cylinders now require 16 AMPS the same goes for the wiring from and to your hot water cylinder and electrical board. The last thing you want is for an older component to cause damage to your new shiny hot water cylinder or home and voiding the warranty in the process.
  7. Compliant Installation And Certification
    No one expects you to be a plumber but it is always good to know a bit more about your installation. Do the research and find out what the minimum requirements are. The best place to start is by looking at the New Zealand Building Code G12 which can be downloaded for free >> G12 HERE. It will only take 15 minutes to get your head around the basics. You will then be able to ask the right questions and the installer will be very careful not to cut any corners. Make sure your installation complies and that you have received a producer statement on completion. This will be very important when you come to sell the property as it becomes part of your LIM report.
  8. Maximise The Size Of Your Storage
    if you have the space, USE IT. The more water you can store the more efficient you become. They all come with 2KW or 3KW elements so you are not ‘using more energy’ you are only heating more water that is stored and ready to be used. The insulation values are the same so minimal heat loss. Considering point #4, another advantage is, should you decide to add an alternative cheaper form of energy later, you will be able to store more water that has been heated efficiently. Because most forms of alternative efficient energy are dependent on having sunlight or the right temperatures, you want to heat as much water as possible during that time and use your storage outside that time. Hence it’s best to store as much hot water as possible. As a small example, the price difference from going from a 180 Litre to a 300 Litre hot water cylinder is about $300.
  9. Licensed Installers
    We cannot voice the importance of this enough. Make sure the installer is registered! Regardless of whether the installation complies or not, the technician must be licensed and registered by the plumbing board of New Zealand. If not and something happens, your insurance will bail. ASK TO SEE THE LICENSE and on completion ask for a producer statement. Selecting an installer that is a Master Plumber will ensure you have someone that is experienced and insured to do the job.
  10. Drain Discharge Size And Location
    Some guys just looooove cutting corners and the discharge pipe is the most likely place. It takes more materials and more time to run the drain to an approved and less annoying position. On most installations, the drain must be 20mm to comply (refer to G12 above). All pressure relief valves from your hot water cylinder discharge water every now and then. This happens as water is heated and expansion takes place. The last thing you want is for a pipe to be sticking out your front door or constantly discharging water onto your footpath. All drains must discharge into an approved point of discharge. What is considered an approved point of discharge? Give us a ring to find out or stay tuned for my next blog.
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What are the pro’s and con’s of a tankless water heater?

Rheem_24_tankless_hot_waterIts not a great thing when your hot water cylinder is leaking and has to be replaced. The only real benefit under such circumstances is that you suddenly get an opportunity to look at a more modern and efficient hot water system for your home.

In New Zealand we are certainly spoiled with unlimited access to gas supply, whether it’s natural gas in metropolitan areas or LPG in more rural areas. With this in mind, the circumstance begs the question whether it is worth looking at tankless hot water heating.

Let’s look at some situations, site conditions and costs to evaluate the pro’s and con’s of tankless water heating.

THE BENEFITS OF TANKLESS WATER HEATING

Lets list some of the benefits tankless gas water heating offers.

Here are the top 5

  1. The cost of natural gas per KW (Which gas to select? see below) is on average 8 cents/KWh + $30/monthly fixed line fee, in comparison electricity is on average 28 cents/KWh offering a significant difference and savings. LPG will cost slightly more but has a much higher burning value. Most tankless water heaters are available in LPG and NG
  2. Continuous flow water heaters deliver an endless supply of hot water that will never run out, as they heat water when you need it, for as long as you need it.
  3. They heat on demand, rather than keeping water hot and stored ready for use, they use less gas than traditional storage water heaters, which is good news for the environment and you. Another important point is that when converting to tankless water heating, you are by default converting to mains pressure.
  4. Tankless water heaters mount conveniently to the wall, taking up less space, which is good news if you have a compact home site or apartment or are just short of space. You can finally convert that hot water cylinder cupboard into whatever your heart desires.
  5. Take advantage of condensing technology which makes some of these gas units 90% efficient saving you even more on your power bill.

THE DISADVANTAGES OF TANKLESS WATER HEATING

What are some the disadvantages of tankless gas water heating?

  • The installation cost is approximately 30% – 40% more expensive than your conventional hot water cylinder installation. Unless you are using a Hydro unit, in most cases an external power point is also required which adds on average another $300 + GST to the installation.
  • Most tankless hot water units incorporate an electronic ignition system replying on 240 Volts. Unlike hot water cylinder storage, If you have a power outage, you wont have hot water.
  • Because cold water has to run through a heat exchanger first, it takes time, this time is translated into a flow rate. Flow rates on Continuous flow water heaters will always be lower than on hot water cylinders which means if you are already on mains pressure, you may notice a drop in pressure. To compensate for this pressure drop, you may have upgrade to the next size Continuous flow water heater. Sizing values are given in Liters per minute for example the Rheem VT 26  will supply 26 Liters per minute.
  • You must always ensure the water heater size you are buying is suitable for your home. If the unit is undersized, you may not achieve the temperatures and pressure you are used to or expect. Continuous flow water heaters are sized by total plumbing points and occupants. for more information please speak to our sales team.

WHAT TYPE OF GAS SHOULD I USE?

Liquid Petroleum Gas (LPG): Is ideal when you dont have access to natural gas or the getting a supply of natural gas is expensive. LPG has a heating value of 102 (MJ/m3), so much more grunt than natural gas achieving high temperatures with less effort using less gas.

How much LPG gas will you need? A 45 KG LPG Bottle will on average evolve 21 m3 of gas at a cost of circa $90 per bottle. A tankless heater of 26L/ minute will use 200MJ, therefore you multiply the heat value by the amount of energy stored (21m3 stored per bottle x 102 = 2142MJ heat available ) The total is then divided by the demand, 2142 ÷ 200MJ = 10.71 hours. Thats 10.71 hours of showering on one bottle, or 64 x 10 minute showers. Great heating value giving you a long supply of gas.

Natural Gas (NG): If you already have NG on your property, no installation line fess will apply and tankless water heating would be very desirable. Natural gas has a heating value of 40 (MJ/m3) meaning you will use more to achieve a desirable heat. This something to consider when comparing costs with LPG. If available on your street and the cost to get a permanent gas line with meter onto the property is free or at low cost, then this option would be an advantage as there is no handling of bottles onsite and you cannot run out.

Our technicians have developed further methods to save you even more on gas by using smart controllers and specialist appliance commissioning processes.

With variations of readily available gases in New Zealand, tankless hot water heating has certainly become the way of the future. Technology and efficiency is improving daily making this a desirable option for kiwi homes. Maybe It’s time you joined the gas revolution!

Hot Water Cylinders NZ are currently running a special to convert to a mains pressure tankless hot water heater for only $2800! Checkout our special deal here. Questions? Give us a quick call.