We at Jim’s Plumbing have decided to write this short blog of things that a house holder should consider before going ahead with installing a Rinnai gas continuous flow hot water system.

It is important that you have a qualified plumber/gas fitter come to your property to make an assessment of what size continuous flow hot water heater you require. Factors we at Jim’s take into consideration include:-

  • a. Number of bathrooms the heater is serving
  • b. Size of gas pipe work that may be required to fuel the Rinnai unit
  • c. Does the gas meter have enough gas flow
  • d. The size of the existing hot and cold pipe work
  • e. Continuous flow heaters are a restricted mains pressure unit
  • f. Companies advertising install prices that are not true

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Number of bathrooms the heater is serving

Rinnai gas heaters come in a variety of sizes which will depend on the size of the unit as to how many bathrooms it is providing for. In my experience it is not just looking at the Rinnai catalogue and making a choice of a sized unit as quite often a unit may be listed as able to feed 2- 3 bathrooms however it cannot do so due to a number of factors which are listed in the above b, c and d.

Size of gas pipe work that may be required to fuel the Rinnai unit

As continuous flow hot water systems require a larger flow of gas than that of a standard storage unit you will need to take into account that depending on the mega joule rating at the meter and the distance of the pipe work has to travel can often incur more costs than the installation on its own. It is not uncommon for a new gas supply needing to be run from your gas meter to the new hot water position so that sufficient gas can be used to run the unit. Many customers elect to go ahead with the extra expense and pipe alterations just to have the convenience of a Rinnai continuous flow so that they are never running out of hot water which a storage unit has a tendency to do as the demand is high.

Does the gas meter have enough gas flow

Your Jim’s Plumbing Rinnai specialist will check your gas meter and check the mega joule rating that it is able to produce. This is very important as in areas where the gas pressures are low continuous flow units cannot be used as there insufficient gas flow to operate these at the manufactures specified settings. Some customers can approach their gas authority who may be able to, in areas where there is low gas flow, put a larger gas meter in which will produce larger gas supply and reducing the size of pipe work requiring to be run to the new units position. We sometimes have had to run 50mm copper (which is expensive) in jobs where the customer has not increased the gas meter or gas pressure is too low.

The size of the existing hot and cold pipe work

A plumber will need to check the size of the existent cold supply to the hot water unit and also the hot outlet pipework sizing as customers can be disappointed that their unit may only supply one fixture at a given time. You can put a larger 26 Rinnai in which in their catalouge may say it feeds more than 1 bathroom however if there is only 15mm water pipe work there is not enough flow to do so- this is something we always advise customers to take into account with any continuous flow hot water units especially when we’ve replaced it with a storage unit which previously may have supplied more than 1 shower at a given time.

Continuous flow heaters are a restricted mains pressure unit

Customers need to be aware that any instantaneous or continuous flow units normally will not produce the same hot water pressure than that of a storage mains pressure type they may have had previously.

Companies advertising install prices that are not true

With the use of internet and other social network mediums it has come to our attention that there are hot water heater suppliers that are advertising the price of the unit and installation at a fixed price. The issue with this is that they are using a lower price to attract the customer to book with them and once onsite the plumber is then advising that there is extra work such as a larger gas supply, power point or it doesn’t meet current regulations and the new price exceeds the original quote by often hundreds and thousands of dollars.

Customers should be aware of receiving quotes over the phone or websites advertising prices. You should ask for someone to come out and quote the job before proceeding. There have been many customers we have attended who have waiting for one of these competitors to come and install at a quoted price over the phone or website only to find out that the price is nowhere near what needs to happen. They use this poor marketing ploy which we do not engage in as customers often feel deceived especially when they have been waiting hours or days for the new heater to be installed- buyer beware.

Once a Rinnai hot water system has been installed it is essential that you ask your plumber/gas fitter to check the water in the shower as many older shower roses are too restrictive in delivering hot water and the unit will detect it as a fault thus not producing hot water or intermittent hot water. Sometimes the shower rose need to be replaced to alleviate this problem.

When changing to a Rinnai instantaneous hot water unit the purchase price of the unit may be only a percentage of the true cost of when it is installed. The below extra costs include:-

  • 1. Upgrading of the gas pipework as this is often required.
  • 2. Altering the hot and cold pipe work to now suite a cont flow unit.
  • 3. Electrical costs for an electrician as a power point is required to run the ignition system.
  • 4. Labour and materials.

This is our personal opinion on what to consider when installing a Rinnai cont flow hot water unit. we are on a daily basis installing these units and highly endorse them due to their many advantages which we will write about in a future blog. If you would like one of our Rinnai specialists to give you a price please phone 1300 133 509, 7 days a week.

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