Gas hot water heaters

[Bob Willson]

I have to replace my current electric water heater and I would like to replace it with a gas constant flow type heater.
I have been looking at the Bosch 21E which is meant to supply 21 litres of hot water per minute at mains pressure.
So far, there have been a few drawbacks to this.
1) cost of heater is just under $1000
2) if there is a power failure then the heater doesn't work as the ignition and control system relies on a 240 volt power supply
3) the gas installer quoted me $587 to change over from my current system to the gas one.

regardless of the above I would still like to go ahead and change over to gas but with the following changes:
1) try to find a gas water heater that does not rely on mains electricity for ignition and control
2) do most (if not all) of the installation work myself.

The current hot water system is about 3 metres from where the new system would have to be installed, so I would need to run 2 lots of copper tube to the new heater (which apparently has to go about 2 metres up in the air in order to raise it above the gas bottles) so that I can connect from the existing cold water in and hot water out connections. - This is no problem at all.

I have already installed a new external weatherproof power point up on the wall next to where the new haeter would have to go. - This is no problem at all.

The only problem area is the actual gas fitting that I would need to do. Apparently, the heater would require a high flow meter that needs to be fitted to the two NEW gas bottles that I would need. There is an existing single bottle gas cylinder that supplies gas for the cooktop and oven. I would like to get rid of this so that I only have the two new bottles that connect to both the cooker and the hot water.
I have never done any gas work before and am unsure how to procede as I do not have a model to work from. I assume that ALL gas connections would need to be flared copper connections rather than pressure fittings ala the type used for water. I would further assume that the existing meter for the cooker would need to be installed in parallel with the heater meter.
Do any members have any experience in this area and if so could they advise me of the requirements?
I fully expect to get loads of 'Don't do it Bob get a qualified gas person to do it for you" and similar comments, but I will almost certainly go ahead and do it myself anyway so any help you can give may welll save me getting blown up.

[TassieKiwi]

Hi Bob

I don't know anything about these, but friends are renting a house and they are alarmed at the rate that the heater chews through the gas:eek: .

[Bob Willson]

Yeah, well I get alarmed every time I get an electricity bill too. I believe that gas is actually a smidgin cheaper to run than electric. But the really good thing is that I will be able to change my air conditioner over to the freed up cheap hot water electrical circuit that for some reason fails to turn off the electricity to the heater when it gets the signal. This gives me constant power on a circuit that is supposed to cut out during peak load times. But sshhhh. Don't tell anyone.

[jackiew]

have you considered electric boosted solar hot water?

[bitingmidge]

Bob,

I have not done the sums (or had fabulously expensive and incompetent consultants do them either) for over twelve months, but every time we've done them in the last decade, gas loses!

If you can run your airconditioner during the day, then you aren't on the cheapest hot water tariff... I can't remember which is which, either 31 or 33?

One needs a full storage hot water unit of at least 250litres (we have three hundred and something) and only supplies 6 or 8 hours of electricity per day. --That's the one you are looking for, and yes you'll a few hundred dollars on the new wiring, but you'll get your money back, and if you enquire you may even get a rebate from Energex for doing it!!

The other can only be used for hard wired equipment like pool pumps etc, (Air Cond can be hard wired) and there is a minimum number of hours supply guaranteed. Our experience was that you only lose power for an hour or so during the night and morning peak times, so it is perfect for everything but cooking.

Now someone who really knows this stuff will come on line and correct me, and we'll all have the right information!

Cheers,

P

[morry]

I'm not sure which but one of the brands now uses a small turbine on the water supply going into the heater. This turbine then supplys enough power for the ignition circuit. I was looking into it for my place in orange which is subject to constant blackouts and thought that I would still have hot water in a blackout. I forgot that the pump from the tank also needs 240v.

[vsquizz]

Bob, have a look at the rest of the Bosch and Rinnai range. When I reno-ed the kitchen we put in a Bosch 16B which uses 2 x D cell batteries for ignition. They last 12 months. Running off mains gas its cheap as chips and no problem if the power is off. In the current model the batteries have been replaced with a "water wheel" which when you turn the tap on this provides the ignition. No pilot lights and you only heat the water you use - and unlimited hot water.

With these heaters it will never really be Mains pressure at the outlet because the supply is determined by the heaters ability ie. 16 l/min. We find the capacity of ours good although we would not want to go smaller. I think an 18 L/min would be excellent. Ours only cost $500.00 about 4 years ago. The Rinnai equivalent was selected as Australia's most economical HWS a few years ago.

Cheers

[Grunt]

Bob,

You should consider subscribing to www.choice.com.au as it has an excellent and detailed discussion and tests on the various hot water system options out there.

$15 for 3 months. You'll save that on your first power bill.

Grunt

[vsquizz]

http://www.choice.com.au/viewArticle...tid=100008&p=1


Cheers

[bitingmidge]

Energex Tariffs - http://www.energex.com.au/for_home/a...?cmd=list&id=1

Two cylinders of FREE LPG


Buy any continuous flow gas hot water system and receive two 45kg cylinders of FREE LPG*


There's never been a better time to buy a gas hot water system from ENERGEX. Because for a limited time, not only will you be able to enjoy continuous hot hot water and even hotter value that a gas service provides, but you'll also receive two 45kg cylinders of free LPG.


*Customers must remain with ENERGEX LPG for a continuous period of 18 months to receive this offer. As an ENERGEX LPG customer annual facility fees of $19.80 per cylinder capped at $39.60 apply. This offer is not available with any other offer. Offer ends 12 November 2004. Available to approved applicants only. Terms and conditions apply.

Or if you want to spend big bucks (and get a $1000 rebate) and save 66% of your energy costs, you could install a heat pump hot water system


Or you could chop wood and fire up a copper in the back yard.

Cheers,

P

[bitingmidge]

Bob,

I had a comprehensive reply with all sorts of Energex links but it got lost in the ether, so check out Energex's web site!

They have a special on at the moment, and will supply two free bottles of gas with every installation. Shop around, we used to get gas connected for free in exchange for a contract to supply gas.

Cheers,

P

[vsquizz]

Bob, Our Bosch came with comprehensive installation instructions, it was a breeze. I had the plumber come out and connect the gas.

A tip, when you plumb the water supply in do not use a floating valve seat (old brass tap) use a stainless steel ball valve. The old tap seat can float and shudder/hammer in low demand situations and starve the heater - not good. The installation instructions may mention this !.

With the ball valve make sure its not the cheap ones with stainless steel ball and silver painted/coated horrible brass body which looks like stainless but will fail within 12 months in some water. If in doubt get one from a marine chandler.

Cheers

[station-rat]

Hi Bob
If your home is insured, leave the gas work to the experts
You don't want to know the problems you can have
Station-rat

[maglite]

Hi Bob,

I replaced my storage heater (240l) about 12 months ago with a mains wired rinaii system(actually a 3 pin plug to an external point) and i swear by it.It has effectively dropped my gas bill by nearly 60% and it is mains pressure at the tap.
It cost about $800 installed but we just mounted it on the wall above where the old storage system was.

Obviously you have to weigh the costs ect and wether the power system in your area is reliable...we have 3 blackouts this year and it hasnt affected us that much at all........i just hooked the camping geni and ran it that way.

Just my 2 bobs worth.

Steve

[namtrak]

As part of our renos we have put in a Rinnai Infinity 24. Can't provide advice on installation or battery ignition, however I can tell you that our energy bills have plummeted - unequivocally. We haven't yet tied the system into our kitchen yet (using an electric Zip heater at the moment) or the ensuite. However we expect the energy bill to drop even further once the Infinity system replaces the Zip heater. The Infinity system is one of the best decisions we have made, the kids can have showers at 37 deg and SWMBO can bathe at 50 deg and I can shave at about 45 deg!!

The only drama is that council requirements include it being 600mm from any opening (door or window) and not under cover. This means we have to move it as we consider where the verandah goes....