In a family home I think a storage system (large one) is the way to go. We had ours replaced a year or so ago by Alinta Assist and the service was great.

Instantaineous systems are fine for small places. And conserve energy when not in use for long periods. They are a pain in the bum if the pilot light keeps going out..... If you install an instantaneous system in a larger home then you will be suprised how the resale value (of the home) goes down...

Pm reelax mate he is in the industry & will help you out

I never really got the point of gas storage. The newer instant gas units don't have pilot lights anymore either.

Im a plumber and prefer instantanious. There are alot of different size units available so you dont have to worry about it not being able to keep up, you just gotta choose the right size. The Rinnai Infinity is a pretty sexy unit!

We went instantaneous (rennai infinity 26l/m) on both houses we built. No pilot light as it lights up when you turn the hot water tap on. Only prob is when there is no power theres no hot water (luckily I have an inverter in my car that I can hook it up to) but saves alot on gas. I got a 4x2 and both showers run fine together. Its also good as if you think someone is in the shower too long you can turn it off lol.

 why would you pay to keep water hot when not using it. never runs out if all have shower at same time. smaller and less corrosion.

 hi all - thanks for the feedback - looks like it's instantaneous then:)

Hopefully Alinta can come out tommorow to fit one... Out of the ones below I was looking at getting the Rheem20 - has a flow of 20 Litres per min - this should be fine right? eg, for a 4x2, mrs n a couple of kids...

http://www.alinta.net.au/pdf/Alinta%20Assist%20Summer%202011%20Bill%20Insert%20WEB.pdf

Your plumber will check with alinta gas the gas pressure out the front of the house to see what size unit you can run.

If you are considering solar heating in the future, the split system uses a storage tank and then runs the water through an instantanious heater to or if required to boost the water temp. This instantaneous heater is the same as what you may install, but must be approved for use as a solar booster, something to do with cut out temperature I think.

Am in the same situation, expecting my electric hot water to die, have already been doing the research.

 Try looking at a Quantum Heat Pump

You also need 20mm tube to run the rinnai's. Most older houses or homes built with a storage unit have 15mm. Sometimes you can get around it and other times you can't. Good Luck! But defo go the instant if you can. I think the bosch units can work with 15mm. I sold HWU's for a few years and as Paul 86 said, the Rinnai 26 is the pick of the bunch.

 anyone of you plumber gurus had experience with Quantum Heat Pump systems and Merlin Gas hot water systems?

I have no alinta gas to my house, even though the bloody pipeline is a stones throw from us, so I will need to be cylinder gass fired.

thanks

Tony, not sure on the system your enquiring about but, Rinnai do a 80mj instantaneous to suit low gas pressure and i would imagine it can be lpg compatable. One of the reasons why storage units are most common on bottled gas, usually only 30 - 40 mj.

 Tony i am a licenced Plumbing Contractor the easyist thing for you to do is look at the Quantum web site and have a read, also look at if your replacing a electric storage you get a Federal Goverment rebate and then you also get a rebate from Quantum which is from the state Goverment. I don,t know what suburb your in but is there no main gas supply down your street. If there  is ring Alinta and ask them what pressure they can deliver to you ever 1.25kpa or 2.75 kpa and that is also worth considering as connection is not very involved, but requires a licence gas fitter to do your consumer side piping connections