Is there a plumber in the House ?

[6maniac]

Looking at replacing a gas storage HWS with an instantaneous system i.e. Rheem / Dux / Rinnai. I have 1/2 inch plumbing for both gas and water.

Q 1 - will these work with those pipe sizes ?
Q 2 - if so, which is the best unit ?

Cheers in advance, Ron.

[Smitty]

gas..needs a 3/4" line for these units (especially if you have any other gas services)
water will be ok with ½"

as Rinnai sez...Gas pipe sizing should be performed using an approved sizing chart, as specified in AS 5601 / AG 601.
Water pipe sizing should be in accordance with AS 3500.

don't forget you may also need a tempering valve or thermostatic control unit
to comply with the AS on HWS (the Rinnai units may allow you to get away without one)

again..Rinnai sez....
WHY WATER CONTROLLERS ARE SO IMPORTANT.
We strongly recommend installing Water Controllers to allow you to take full advantage of all the benefits available:
SAFETY
* Precise temperature control reduces the chance of scalding, particularly for children.
* Enables you to bath the baby at (say) 38°C, the kids at 40°C and yourself at 42°C.
COMFORT
* Controllers eliminates temperature fluctuations should someone else turn on another tap.
* Simply select your desired temperature and turn on the hot tap... never use the cold tap again!

and yes..I recommend Rinnai (over Bosch or Dux) even though more expensive



hth

Smitty

[6maniac]

Thanks mate - guess I have to get the same unit as the one that's shit itself.

[the kid]

Cheapest solution (and the quickest) is to replace same for same . The Mj rating of the unit you replace any gas appliance with will determine the size of the pipe you need from the meter to the unit .An instant unit has a far greater demand than a storage unit so bigger pipe . Lenght of pipe and demand along the pipe . Should only be 1/2 inch for about a meter or so , thats all . Next issue is that the exist gas service has to be tested , if things are done by the rules
Any gas service that is old ie still in gal pipe might not pass inspection . Also if a plumber is doing things properly the sizing should be recalculated for the whole house and since there so many poorly designed gas services out there it might not pass .
A 3/4 gas pipe may run an instantaneous HWS if installed close by to your meter , but whack it down the back and look out
Now ?? How far is the flue from a door window or opening ?? This too can change a bit depending on the Mj rating .
Sales pitches from the manufacturers don't allow much for the installation costs associated with the plumbing regulations .

[6maniac]

G'day Kid, existing unit is a Rheem Weatherline ? I think ( 135 litre ). There is only me in da house - does that affect the equation ?

[Smitty]

G'day Kid, existing unit is a Rheem Weatherline ? I think ( 135 litre ). There is only me in da house - does that affect the equation ?

only you? want a cheap replacment?
go another external HWS like the Rheem or Dux or Aquamax
will use the existing gas line and water plumbing

and most plumbers won't charge an arm and leg to replace it (just get 'em to buy at Bunnings
and NOT use their account at Reece )


hth

Smitty

[the kid]

G'day Kid, existing unit is a Rheem Weatherline ? I think ( 135 litre ). There is only me in da house - does that affect the equation ?

No The energy used is constant with that type of unit . The instant units can vary there energy consumption but are pipe sized for a maximum consumption .
Nothing wrong with the standard 135L box on the side of the house . Hot water is the cheapest luxury we have .

[esie]

We have been looking at the Rinnai Instantaneous gas hot water system, to replace our ageing (and as of yesterday, dead) electric hot water system. Trying to get a straight answer on the process of installation has been near impossible! As far as I can make out, we buy the system (is it best to buy direct from the manufacturer?), then have it installed, advise Origin to set up the account, then get a certificate from the gas fitter, send that to Origin, then eventually (up to a month later) it will take effect.

I haven;t looked at any of the other instantaneous hot water systems, but generally although Bosch is good quality, they are expensive.

[the kid]

I am thinking that you dont have a gas supply to your house ?
Dont know about Qld , but you used to be able to get the supply run in from the street and it would only get a meter installed after the gas service had been run around your house and signed off by the plumber .
Could be a bit of a wait to get the service run in from the street , so what to do if the electric has died ? Cold showers etc ?
I would if , I was in your situation hook up a 50l electric as a temporary HWS till the gas came through ( I am assuming still that you dont have gas on the property) and have all the pipework run to that 50l unit to suit where you are going to locate the new gas unit so it wont be a waste of pipe and labour . This is of course easy to say if I was doing the work for myself and could off load the 50l unit onto another job later .
There are other variables , how long are you staying in the house , do you own the house , future reno's , etc ???
A good plumber should be able to sort it all out .