New house - Best Hot water System???

[briann532]

We are building a new house hopefully starting in a few weeks.
The builders standard hot water is a Rinnai instant, but we don't have gas to our property and I done the maths on bottles and its too expensive.

We can go for either a heat pump electric or an on roof solar.

I am wondering peoples thoughts and or experiences with either or both?

I am going to be installing a 20 KW PV system so electricity is no problem, but I have heard the heat pumps can make a little bit of noise.
I also am considering running electric boost on a timer so it only operates during the day when the panels are producing.

I install solar systems, but unfortunately don't know much about hot water systems that I don't deal with.
Everyone I ask just recommends what they sell or install.......

Any help appreciated.
Also - Tin roof, no shade on acreage with full sun.

Cheers
Brian

[Snapman007]

Not sure where you are, but our biggest household running cost is water. We have elec hws on a 10 yr old home and solar with a 50cent fit. Elec hws is costing us money and is possibly near the end of its life. We are considering putting in 3 on demand hws, one in the kitchen and one for each bathroom. Laundry can branch off the bathroom.
The amount of water wasted waiting for it to run hot and then the elec to replace it is losing us money.
Basically what I'm trying to say is work out how long you plan staying there and factor in the cost over that time. Short term put the cheapest system in, long term........

[austastar]

Hi,
  If I was building again, I would go instant gas or electric with a solar pre-heat. Use the solar to get what ever heat is available and then top the heat up with the instant heat just before it comes out of the tap.
Best of both worlds - low case heat loss from a static hot tank if the sun won't heat it up, and water already pre-warmed won't need as much $$ to get it up to temperature.
Cheers

[briann532]

We are building our "dream" home on acres and plan to stay there a while.
At least 15 years before kids are gone so it won't be before then.

I am not trying to penny pinch, I just want the best info before I go ahead.
Everyone I talk to seems to give me a different opinion.
Evacuated tubes, instant gas, heat pump, solar, gas boost, elec boost, full elec on solar, and even solar with gas/elec boost.
I'm currently thinking of going a rooftop solar tank with daytime PV solar boost on a timer so I don't heat up during the night on full grid rate.
BUT - and there's always a but......
I have recently been told that a heat pump will be cheaper to install and cheaper to run long term???

[Coiled]

From the research I have done, Heat Pump HWS work quite well and do use quite a bit less power. The noise is supposedly pretty insignificant and was described as less than the outdoor unit of a 2.5kw split system AC.

The only negative that was suggested to me by an air con mate was that if you have issues it could be a pain with getting and cost of tradies as it has plumbling, electricity and refrigeration.

I was going to go ahead and get one but as I am about to put solar PV in, I am figuring that the $1,000 I save between the std elec and the heat pump HWS can go into the solar PV and this system should easily run the HWS making it a non-issue given the feed in tariff is insignificant.

I will be watching this with interest as I haven't crunched the numbers on this aspect yet.

[rags]

Brian plumbing and gas fitting is my game and my thoughts on hot water heaters and your senaro.
Firstly forget the heat pump idea compressors are better for running air cond units or fridges, they can be noisy and costly to fix when they fail.
Rinnai type heaters are great with natural gas but as your maths says they canbe dear to run, your can sometimes get cheaper gas rates through Elgas if you have a high gas usage, but you also run the risk of getting a cold shower if you run out of gas.
With the solar my opening comment is to consider the cost overall , a roof mount (hi line) will cost about $4500 and for that money I could buy 4 electric storage heaters for the same $ and they are supper simple to fix an element or thermostat! Also as you are on acres I guess you will have tank water pushing about 300-350 Kpa so the heater wil last a long time ( my heater in our house that we just sold in Kurrajong Heights lasted 27 years and I only replaced it as I moved it to build a new deck). The running costs on off peak combined with your solar electric panels rebates needs to be considered.
But if it is solar you are correct to consider a hi line system over a split system. This system is a proven simple system with no circulating pump. You should also consider the frost free units that utilise a glycol type fluid for circulation. I would suggest a stainless tank unit like Edwards (owned by Rheem) or maybe Ecomax. The evacuated tube panels typically aren't available in hi line systems.
Your builder will probably contract separately for the solar with his plumber providing the required points for connection of the roof unit.if you are looking for a company to quote (I thinknyour block is out in the Hawkesbury) I can suggest Limcora who are out at McGraths Hill http://www.limcora.com.au/solar-hot-water.html
Hope this helps

[gronk]

I'm currently thinking of going a rooftop solar tank with daytime PV solar boost on a timer so I don't heat up during the night on full grid rate.

Are you also going to be on grid ??

I would go roof top solar...KISS...but with a family, you'll need to heat it of a night.

[prodigyrf]

I'm with rags with a simple off peak electric HWS all things considered but get yourself a big sucker like the Rheem 412L job-

http://www.rheem.com.au/Products/domesticproducts/electric/rheem491492serieselectricwaterheaters/rheemelectricwaterheater491400

I got over 14 yrs out of the last one (Adelaide hard water remember) because I keep an eye on the anode and had to replace that once and it was around $90 plus I did an element and they're cheap and easy to replace like the universal thermostats all over ebay-

 http://www.ebay.com.au/itm/HWS-ELECTRIC-HOT-WATER-ELEMENT-3600-WATTS-ELECTRICIAN-TOOLS-RHEEM-3-6KW-BULK-BUY-/180931922321?hash=item2a20620991:m:mK8oXIz09SF1JrT7-lj_Hmw

http://www.ebay.com.au/itm/ELECTRIC-HOT-WATER-TANK-THERMOSTAT-SUITS-RHEEM-DUX-AQUAMAX-RINNAI-APRICUS-/291048827454?hash=item43c3dcaa3e:g:hhwAAMXQRkdR5H~V

Pays to whip out the anode with a new install and coat the thread with nickel antisieze for easy checking and you won't go wrong. With overnight heating you shouldn't run out with a single element big sucker but if the bloody women won't get out the shower fit these as they blast the skin off their backs like they want yet control the water flow-
http://www.ebay.com.au/itm/ABS-Water-saving-Polished-Bath-Top-Shower-Heads-Sprinkler-Round-for-Bathhouse-/400763113933?hash=item5d4f57d1cd:g:RzwAAOSwxCxT~AL6

So what about the power bill you ask? Well looking at 92 days from July 23 to Oct 22 the water heater for her indoors, princess and I chewed 806kwhrs at a cost of $112.60 off peak out of likely around 2400kwhrs which would normally cost about $590 for the quarter (I've got solar feed-in so I've had to do some figuring there) with a supply charge of $64 included in that. Now I know from the past that the HWS consumes around 30% of the household kwhrs but with peak power rates up to 33.77c and off peak at only 13.97c the proportionate cost drops significantly (around 19% on the above figures) Yes a Rinnai gas instant might cut the HWS bill but then the gas supply charge negates that and why I stay all electric with an induction cooktop to boot which is apparently as cheap if not cheaper than gas.

Yeah the heat pump would be cheaper to run but noisy and higher capital cost as is solar and you'd have to factor in extra power boost in winter and you have to get up on that roof to change the anode, etc or pay someone to do it so I'm with rags on this one and the KISS principle while we have that offpeak concession power.

[prodigyrf]

And I'll have the element or thermostat changed while you're still climbing on the roof-
https://www.youtube.com/watch?v=__foKrziH1w
but only use the sickle shaped elements as I discovered with a new one way back when the straight one it came with blew just out of heater warranty. That's because the bottoms of the cylinders are dome shaped and as the anode deteriorates it deposits its detritus right in the middle of the dome and if the straight element sits in that it will corrode and die prematurely OK?

[MarkVS]

I have 2 hot water systems. A instant bottled gas systems for one side of the house(only does main bedroom bathroom so ideal for the small requirement), and an off-peak standard electric for the bulk/rest-other side of the house (other bathroom, dishwasher, washing machine etc.)

The costs for the off-peak electric work s really minimal to run/qtr, especially at offpeak rates, and considering the units themselves are quite cheap to start with, and get good long life out of them, easy/cheap to fix.

I looked at solar etc to replace the Off-peak electric system at one stage(when I thought it was playing up), but decided against it as the up front numbers just didn't add up to me, in comparison.


MarkVS

[Rocky and Bullwinkle]

We live in the country so we only have bottled gas, so we changed to electric with solar. We have evacuated tubes, very efficient, our Off Peak power usage has dropped significantly. I we had access to mains gas it would be solar with instant gas boost. I hope this all helps!
We also have solar panels and got in on the good Vic Tariff.

Greg

[GBC]

The original series of the split solar and heat pumps are failing now and are expensive to repair or replace. A few companies have gone under as well.
We have a 12 year old Edwards roof mount staino tank job which was a bit exxy. Our family of 4 will rarely if ever use all the hot water. It needs boosting only after say three days of continual rain etc - maybe three times a year.  I wouldn't have anything else these days but you may end up with a roof space conflict between your hws and your 20kw array all wanting north facing real estate up there.

Further savings with solar come with pre filling your cooking pots with hot water before boiling and the ability to wash clothes in hot water without extra expense.

[UIZ733]

I have a mate on acreage. No town water but is on the power grid. He has a large grid-tied solar setup. He has a heat pump with one of those tap systems that 'recycles' hot tap water until the tap delivers hot water. He researched all possibilities thoroughly. Overall he is very impressed with his setup.

[Julian Kaye]

 I spent a few years in the solar industry and electric  boosted solar works well. Evacuated tube technology like Apricus is extremely efficient. It is a good choice, but, if I had natural gas connected I would go instantaneous gas every time. Hot water on demand and no storage tanks.

[GBC]

I have a mate on acreage. No town water but is on the power grid. He has a large grid-tied solar setup. He has a heat pump with one of those tap systems that 'recycles' hot tap water until the tap delivers hot water. He researched all possibilities thoroughly. Overall he is very impressed with his setup.

ring main

[prodigyrf]

I have a mate on acreage. No town water but is on the power grid. He has a large grid-tied solar setup. He has a heat pump with one of those tap systems that 'recycles' hot tap water until the tap delivers hot water. He researched all possibilities thoroughly. Overall he is very impressed with his setup.

Makes sense if you're running off your own tanks but not with mains water-
http://www.clearchain.com/blog/posts/explaining-the-concept-of-a-hot-water-plumbing-loop

Perhaps grandma and grandad were the real greenies with the coal gas fired Paterson heater over the bath but it used to scare the poop out of me as a tacker

[UIZ733]

ring main

That is the one. 

[stephenh1235]

Being a retired plumber my vote is for solar & experience over the years recommends closed circuit models-preferably Solahart  brand.Initial outlay is a big hit,but power savings far outway.
Steve

[Fizzie]

Hi Brian

I'll throw my .20c in as well 

We put an evacuated tube split system in about 3 years ago now. Got the system here: http://solaroz.com.au/shop/complete-systems/conversion-kit/prod_170.html for about $1500, then did a diy install, with tubes on the roof & the ~400l tank at ground level.

We're on the Gold Coast & the tubes face virtually due west, but still punch out hot water! We still have electric boost fitted to tank but it's switched off in fuse box as not needed - since installing, we've only boosted the tank 3-4 times each year. Tubes work well enough & tank retains enough heat that only need to boost after about 3 days of heavy cloud / rain.

Just checked now & after 3 days of patchy cloud, showers & storms, tank is at 55`, which is well & truly hot enough!

[prodigyrf]

Being a retired plumber my vote is for solar & experience over the years recommends closed circuit models-preferably Solahart  brand.Initial outlay is a big hit,but power savings far outway.
Steve

Show us some hard figures on that and these sorts of complaints with closed circuit solar are not uncommon amongst my circle-

http://www.productreview.com.au/p/solahart-l-series.html

http://www.productreview.com.au/p/edwards-l-series-2.html

They have heating anodes elements and thermostats to wear out just like mine but owners have to pay plumbers to climb on the roof when they dick themselves and they've  already paid dearly upfront and pay peak rates for the boosting needed because they don't have enough storage for the average family. Evacuated glass tubes are brilliant solar gatherers negating much power boosting but then they're an expensive add-on to my standard storage HWS with the added pump and circuitry to fail plus the peak power to run it.

The question is always one of payback for all that and certainly in SA with our hard water a lot of owners only get 8-10 years out of their HWS because they're oblivious to the anode and in any case paying plumbers to regularly check and/or replace is not cost effective so the first they know about it is leaking water. Payback for more complex and expensive systems can be better in soft water areas but I suspect most owners look at some headline power bill savings and neglect the upfront capital cost and ongoing maintenance bills with all of it.

 A year ago when mine died I wheeled in a new Rheem Optima (Optima means simply bigger anode for longevity) for $1500 and it hitched up exactly like the old one that was 14.5 yrs its senior and since I'd only replaced the element in that one 18 months earlier I kept that element as a spare. That Rheem Optima is all 'solar ready' but where's the savings when it's only costing me around $450/yr in power to run now?

[prodigyrf]

When you're all electric and not paying an extra gas service charge it makes more sense to invest in an induction cooktop that works like gas at the touch of a button-
http://ultraflexpower.com/learn/efficiency-of-induction-heating/
Apparently Asia is beginning to wake up to instant induction water heating to complement their cookers whereas standard electric element instant has required 3 phase power to try and match gas instant heaters-
http://www.hometone.com/induction-water-heater-uncommon-design-common.html
Bit of a head scratcher as to how they work given you need an iron or steel mass to work and that means rust if exposed to hot water but perhaps they encase it in stainless like induction saucepans.

[stephenh1235]

Show us some hard figures on that and these sorts of complaints with closed circuit solar are not uncommon amongst my circle-

http://www.productreview.com.au/p/solahart-l-series.html

http://www.productreview.com.au/p/edwards-l-series-2.html

They have heating anodes elements and thermostats to wear out just like mine but owners have to pay plumbers to climb on the roof when they dick themselves and they've  already paid dearly upfront and pay peak rates for the boosting needed because they don't have enough storage for the average family. Evacuated glass tubes are brilliant solar gatherers negating much power boosting but then they're an expensive add-on to my standard storage HWS with the added pump and circuitry to fail plus the peak power to run it.

The question is always one of payback for all that and certainly in SA with our hard water a lot of owners only get 8-10 years out of their HWS because they're oblivious to the anode and in any case paying plumbers to regularly check and/or replace is not cost effective so the first they know about it is leaking water. Payback for more complex and expensive systems can be better in soft water areas but I suspect most owners look at some headline power bill savings and neglect the upfront capital cost and ongoing maintenance bills with all of it.

 A year ago when mine died I wheeled in a new Rheem Optima (Optima means simply bigger anode for longevity) for $1500 and it hitched up exactly like the old one that was 14.5 yrs its senior and since I'd only replaced the element in that one 18 months earlier I kept that element as a spare. That Rheem Optima is all 'solar ready' but where's the savings when it's only costing me around $450/yr in power to run now?

wow,didn't know I'd have to qualify my opinion or choice of product recommendation, but I did say "closed circuit", the links both refer to "open circuit" systems

[mrdenn1s]

Heat Pump all the way

[D4D]

We had an off-peak electric boosted solar with tank on the roof, Solarhart. It was awesome until it died, 15 years of service. Replaced it with a Rinnai instantaneous, only issue I didn't realise is, if you have no power you have no hot water...

[prodigyrf]

wow,didn't know I'd have to qualify my opinion or choice of product recommendation, but I did say "closed circuit", the links both refer to "open circuit" systems

I misinterpreted closed circuit as meaning not being pumped around which those rooftop jobs avoid but then what you're referring to does have the same complexity for no savings for mainstream urban consumers as another link shows.

It's been a useful exercise for me to pull out the bills, look at the current options and revisit past decision-making to see if much has changed. I'm still with rags and all electric on my figuring so what about instant gas heating? Well I looked up the fixed supply charges and Energy Aust is 95.04c/day while Origin is 75.449c/day but they juggle steps and rates but that's between $275/yr and $347/yr compared to my total electric HWS off peak bill of around $450/yr before using any gas. You'd have to like gas cooking a helluva lot to forgo all electric with induction cooking to have 2 utilities nowadays in my book.

I'm still with rags on all electric and the KISS principle although I can maintain any of the systems myself. I appreciate it's not easy to sort the wheat from the chaff with these things and there's a lot of advertising hype about and complex tariffs to thoroughly confuse everybody.