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hedwig
20-08-2007, 07:58 PM
Finally we have tgot a solar hot water!
It's running since a week and all the week we didn't have much sunshine.
But I decided tio run the thing in the extreme way: The electric booster is out.
Why: it will save us nearly 100% of electricity for hot water. With the little sunshine we've got there is still some lukewarm water - enough to shower (but not these wasteful 4minutes showers).
For dishwashing sometimes I heat 1 or 2 litres in the electric water heater - far more economic than heating more than 200 l on the roof.

Cosmic
20-08-2007, 08:38 PM
What brand is the system?

hedwig
22-08-2007, 09:52 AM
edwards

Cosmic
23-08-2007, 10:32 AM
I ask this because we just got a dux gas boosted solar system and we think it uses too much damn gas! We wanted to turn off the booster and have pure solar and asked the company who installed it but they said nooooo, it will stuff up the computer. Has your got some fancy computer controller? Did you ask about turning off the booster or you just did it?
I don't understand how it saves power when everytime you use hot water the gas kicks in. I don't get what part the sun plays. It cost $5000 and we feel ripped off.

hedwig
23-08-2007, 04:27 PM
no it has nothing fancy. HOwever they didn't install it were we firstly wanted because they said that tere is no space.
They didn't even ask when they decided to change. and now it is not directly over the shower! Te insulation of the pipes they did only halfway.
I am very upset aout the way australian trradespeople work. No sense of quality and they don not think of communication. They even didn't let me use their ladder to climb up to see what they're doing!

But they worked not too bad we have other experiences. Did someone explain you that there is a fancy computer thing?
I must say that we were a bit unconcious as well. The quote didn't mention many technical details. Our system runs without pump, which was important for us (the less fancy things the less problems)

Cosmic
23-08-2007, 04:57 PM
It's this one http://www.dux.com.au/products.php?name=D1FNP3W2AC
It has a computer thing on the side. They have tried to explain it but I still don't understand why it uses so much gas. I just want to turn it off especially in summer but don't want to break it. Going to have to call dux I think and try and find out if it really is bad to turn the gas off. I mean, in Brisbane summers you don't need the gas on.

gardenlen
24-08-2007, 04:13 AM
hedwig,

not a lot of options as to where on the rook it gets located that is determined by the suns track and generally they are put on the north roof or north/east roof, amybe if they haven't installed it on the right part of the roof you should call them back and have them move it??

generally they have either a gas or electric back up for these inclement days (when solar collect almost no heat), in some cases where it is electric they provide a switch so you can turn to over ride on, but guess now that could be computer controlled. a wind system would have been good of late hey??

reckon of late your system will be running on electricity though?

len

hedwig
24-08-2007, 12:40 PM
no, The place is stil OK, but two metres farer that the first site. I am not used to this kind of working: I think if a companiy change things they have to talk with the one who pays.
Our system is electric boosted. And there is a switch. (Maybe the switch box contains a computer??) they turned it on saying that we can turn out when wh're having sun. I turned it out immediately.
And we didn't have sun until now, it rains since a week . But the water is still
not cold, a bit less than lukewarm.

Cosmic
24-08-2007, 01:01 PM
Oh wow a swtich. That would be great.

permasculptor
24-08-2007, 01:58 PM
Is it possible/have you tried turning the gas off?

gardenlen
24-08-2007, 04:22 PM
hedwig,

i've heard it before from others anyone who installs sells solar devices seems to treat consumers with some sort of contempt, they feed consumers a whole lot of technical gobbldy goop and if you ask questions or want more info' they get bored with you, seems like if they say buy this that is what you should do as you the consumer don't know any different.

that is why i have been trying to get first hand stories from people who ahve done it so others can read that and then go buy the best for their needs instead of relying on unreliable pushy sellers. we went through that and have heard others as well and don't go to them with a problem they don't want to know you, the whole industry has no integrity by the seems of it.

one bloke told me, he had to protect his business and would tell me what i needed only when we where ready to pay up front.

and prices are going up because of gov' rebates.

len

Cosmic
24-08-2007, 05:46 PM
the guy was shocked that we wanted to turn off the gas. He couldn't understand why we would want to do that. Dur!! To use the sun. He said it will stuff the computer. I need some real information as I dont' want to break a $5000 system.

gardenlen
25-08-2007, 03:39 PM
cosmic,

what capacity tank do they come with?

and hedwig,

what sort is yours? capacity price etc.,?

tia

len

Alex M
26-08-2007, 09:59 AM
Cosmic, I can't imagine what the computer is all about. If the sun is heating the water, the thermostat in the tank should simply not turn on the heating flame, although the pilot light will always burn a small amount of gas. If the gas is doing all the work, your solar panel is just a useless appendage. You should be able to turn off the gas, if only to see if the panel actually works at all.

One of best ways, in my opinion, to ensure that you have plenty of hot water at lowest cost is a solar/electric system connected to off peak 1, the cheapest electricity. If the solar panel has done its work during the day, the electric thermostat in the tank will not turn on at night. If there is not so much sun, or you use most of your hot water in the evening, the thermostat will turn on, using electricity to heat the water so you can have a hot morning shower.

It shouldn't take long for solar panels to heat your water to a satisfactory level on a sunny day. If you don't want to pay money to heat your water, you turn the electric booster off, and structure your water usage around its availability. That is, you might find one morning that you have plenty of water heated by the previous day's sun, or that you have to wait for the day's sun to heat it for you.

My ideal system uses a combination of a slow combustion cooking stove, off peak electricity, and solar panels. In cold weather, the stove heats the house and the hot water, while in warm weather, the solar panels do all the work. The off peak fills in the gaps.

Hedwig, I'm sorry to hear you had such a negative experience with the installer of your system. Sadly, too many tradespeople have this "you'll get what you're given" attitude towards clients. Tell them, in writing, what bothered you, and don't recommend them to your friends. If they can't be bothered to explain the entire process to you, they're not doing their job.

Cosmic, you have every right to expect the service you paid for. Tell them what you expected from the system, and demand that they explain the workings of the system to you. If you're still not satisfied, complain to the Building Services Authority http://203.63.40.65/Home/Consumers/Comp ... laints.htm (http://203.63.40.65/Home/Consumers/Complaints/ResidentialAndCommercialBuildingComplaints.htm)
or to Fair Trading http://www.fairtrading.qld.gov.au/OFT/O ... enDocument (http://www.fairtrading.qld.gov.au/OFT/OFTWeb.nsf/web+pages/650926B526C454BE4A256B4A00119C28?OpenDocument)

davo
26-08-2007, 07:07 PM
Hi guys.

I bought a Solarhart solar hot water system secondhand and installed it on a remote property in Southern Queensland (near Tara) where there is no electricity or gas on the place.

I found the Solarhart gave me hot showers with no problems. Summer the water was VERY hot indeed, but even on cloudy days and in winter it was warm enough for a quick shower.

So no electricity OR gas, and it worked fine. I'm down in Sydney at the moment so I can't really say how the hot water is doing, but I don't see any reason for it to have stopped working unless a pipe is blocked or if the header tank runs out of water.

It sounds to me like the tale you've been told about damaging the computer is a load of bull. But it's your $5,000.

Cheers,
Davo

Cosmic
26-08-2007, 08:58 PM
The panel works as on sunny days the water comes out damn hot and cloudy days it is not scalding. The gas turns on as a top up but it tops up every time you use it. I am not aware of it turning on unless we have used to water for a few minutes. It's a 170 litres system. It's a split system and you can hear the water pumping to the panel when it's sunny. The proplem is the gas turns on to keep the water at a constant temperature and endless showering but I want an option to have the hot run out when the solar heated water is used up.
How do you turn off gas? There is a knob on a pipe, would you just turn that?

Alex M
26-08-2007, 10:42 PM
you can hear the water pumping to the panel when it's sunny.
There's a pump? WTF? Sounds like another triumph of overcomplication. I'll bet some half-witted engineer, educated beyond his intelligence, probably won an award for that one. No wonder there's a computer. It makes up for a simple failure of design. It probably monitors water temperature and sunlight and turns the pump on to send the water to the panel. Whoever is responsible for it should be shot. In a properly designed thermosyphon system, such as Davo's solarhart, the sun does all the work. That's the point of solar energy. Other energy sources are optional, and then only when then there's too little sun, or too much demand.

How do you turn off gas? There is a knob on a pipe, would you just turn that? I would, and if it buggers the "computer" just tell them you don't know what happened. Get the bastards to fix it under warranty - twice a week, until the warranty expires. At least you can make them work for their ill-gotten gains.

A computer. Unbelievable.

bovine_blue
26-08-2007, 11:19 PM
So does anybody know what a good system to buy would be? Specifically for the cold of Tasmania.

gardenlen
27-08-2007, 06:00 AM
b_b,

set up a wind generator with some batteries and power it that way, don't know what cosmic has though sounds complicated??

thought the way solar systems worked was to use solar collectors to provide power to the heater and that the hat water tanks was much like an electric one in that the stored water gets heated and the water you need runs though pipes in that hot water.

you can using an ordinary hot water system set up some plack hose on a north facing roof and with a smallish pump heat the water in the tank as the heater does, buit like solar systems it only works on sunny days, and of course only works in daylight hours.

cosmic,

what brand do you have? do you have their web site link??

5 grand is a lot of money for hot water, especially if you aren't happy.

hedwig,

are you going to tell us about your system size cost whatever??

tia

Cosmic
27-08-2007, 07:39 AM
http://www.dux.com.au/products.php?name=D1FNP3W2AC
It pumps the water because it is a split system but yeah, I could design it better. We're stuck with it now. the tank is on the ground, not the roof.

gardenlen
27-08-2007, 08:38 AM
you won't be the only one cosmic!

still would wonder at maybe something simpler and less expensive being able to deliver not only real power savings to the consumer but real saving to the environment.

our electric system has a 250 litre tank this means for the average family a lot of hotwater, most solar units are considerably smaller and heaps dearer, ours cost under $700 that makes it affordable to all and doesn't use valuabel mis-appropriated gov' funds that could be better spent in health or education whatever.

so if you bought a couple panels and a small wind generator, a couple of batteries and an inverter, and then ran you exisiting unit with that power might that might then be out of the ""feel good"" arena, plus come tank replacement time that is all you have to replace.

simple maths says that keeping the ball park (somewhere sometime gov' sunbsidy will cease and unts won't get cheaper) even a $5k unit is going to cost $250 per annum to cover initial outlay then another $250 at todays prices to cover replacement in 20 years, for the poorer in our community that is an expensive legacy.

would like to here from hedwig??

and as we have found those dealers in the renewable industry are in about the same class as door-to-door salesman or insurance or used car salesmen.

we are having satisfaction problems with a much simpler designed pool heater but still expensive around the $3k marke because it comes under the ""feel good"" charter, and we are getting the same issues with the supplier as i have heard a lot of others are as we did with our initial enquiries into solar inquireies purchases.

len

permasculptor
27-08-2007, 09:00 AM
The general feeling of my permi group was that edwards were the best. but it sounded like service and installation problems were solaheart.s downfall.It would be good to know which is the most efficient.

Alex M
27-08-2007, 12:12 PM
Cosmic wanted to buy a solar hot water system, but was sold a solar-assisted gas system.

Its purpose is not to free the consumer from purchased energy input, but to maintain dependency on it. This is why the gas can't be turned off. It is also why I am so disparaging about its designer, who probably wasn't even conscious of what he was doing.

The industrial system will always design its products to sustain itself. It's a difficult mindset to escape. Graduates of our industrial education system are also industrial products. Their output will naturally support the system that created them.

gardenlen
27-08-2007, 12:23 PM
good point alex,

as you say most if not all manufacturers designers are a power unto themselves, they design and make stuff that consumers are indoctrinated into buying due to a perception of efficiency.

my push is to amass some information for those who want to delve into the murky waters of this ""eco' friendly"" ""feel good"" stuff that they may be better informed and then put pressure back onto the industry maybe to clean up its act?

so though we mepathise with cosmics situation and we don't hold any fault against cosmic we should all learn from these expereiences so we get it more right as we go along. and if cosmic is on butane gas that is expensive stuff reliant on the oil companies a much as what petrol is, not so bad if you can access natural gas.

len

Alex M
27-08-2007, 01:10 PM
The system is predatorial.

Roman orator, Cicero, famously posed the question, Que Bono? Who benefits? It's worth keeping that question in mind when making what we now call "consumer choices".

gardenlen
27-08-2007, 01:16 PM
yes alex,

but i bet not many conumers have that morale in mind when buying so called beneficial products.

guess that saying can go hand in hand iwth "let the buyer beware" i prefer "let the buyer be warned" or "let the buyer be informed", and from waht i see in these sorts of topics & even sea/tree change there is little of the above, in any criterias (if there is a criteria even? with "feel good" i don't think there is a criterai above "it feels good at the time").

len

Cosmic
27-08-2007, 02:39 PM
I am so depressed about our system now. Even more than before. It's not like we could afford to buy it but wanted to have solar badly when the other one broke. Solarhart didn't even ring us back so we didn't buy from them.
It's natural gas.
Everyone is just out to screw you.
Can I swear on here.
I hate this world.
That's it.

gardenlen
27-08-2007, 04:01 PM
we're on your side cosmic,

at least natural gas is affordable, we used to have that opportunity at 2 addresses so we opted for on demand gas which is the most efficient way, but in reality you wanted a solar unit with either gas or grid power backup.

anyhow for now the best i can offer is hang in there try to move on for now.

len

Uncle Yarra
27-08-2007, 07:51 PM
Cosmic,
Have a squiz at my set-up.
http://pobbs.briarthicket.net/viewtopic.php?t=34
What you may be able to do is use an instantaneous gas heater with a solar valve. Use your existing tank as just that - a tank, send the output to a solar valve, if it's hot enough, it bypasses the IHW unit, if not, the IHW adds just that heat required to make up the difference - ONLY WHEN IN ACTUAL USE (much more efficient).
You'll see it as the shiny thick T-section with the red knob in the attached link.
So for your system you could retro-fit another IHW system and valve (and turn off the gas to your current tank). This is probably an unnacceptable extra cost for you - understandably so. Another alternative would be to sell the tank you have, get a plain one with good insulation and use the funds to offset the cost of IHW components.

Alex M
27-08-2007, 11:30 PM
Everyone is just out to screw you.
Can I swear on here.
I hate this world.
That's it.

Don't be depressed, Cosmic. Just do your homework and look into ways to make your system more efficient. Looks like Uncle Yarra has a good set up, and you can learn a lot about it. Soon you will be quite an expert on solar hot water systems.

That's what this forum is for, after all, to enable us to share our experiences, and benefit from them.

Remember that nothing is really wasted. Everything can be used to our benefit.

My last post was edited at the last minute to remove an angry tirade against the industrial system. I don't want to "smash the system", but I am convinced that is stark raving, barking mad, geared almost exclusively for profit, rather than the general welfare, AKA the Common Wealth. But it also produces marvellous technology like Uncle Yarra's evacuated tube solar collectors, and of course, the ipod.

Don't hate the world, Cosmic, just help us fix it.

hedwig
28-08-2007, 10:00 AM
Cosmic,I think you have to call/write the company which manufacters the system (it is important as well thatthey know what their tradespeople are doing) and ask them.
I have no idea but with gas heating systems you have alway to take care that the flame is not out while the gas is running.
I really cannot imagine that you can't turn it off. And you have got a warranty.
Our system was installed and immediately a week of rin came. It never had the opportunity to heat up properly, but we had at least lukewarm water. Now the sun is out and the water is hot and I will go on running the system without booster. WE've got the booster in case we must sell the house and not everybody is that canny.

gardenlen
28-08-2007, 11:18 AM
with gas the flame would rarely go out if ever while you where running hot water but with some units the pilot flame can go out with strong winds etc.,. then you need to re-ignite the pilot flame.

solar hot water system need a booster whether it is gas or a/c power.

still would like to here about your system "hedwig"?? you know cost excluding rebate etc.,.?

whether telling the comany will do much (might even make you feel a whole lot worse) at all is debatable, the person who sold you the unit may simply say this is what you decided that you wanted, they usually cover their tracks well.

len

permasculptor
28-08-2007, 12:43 PM
An expensive lesson is a valuable lesson Cosmic share your experience as much as possible.A great many good people are out there wanting the information you now have.

the end of suffering comes from the living of joy!

hedwig
28-08-2007, 06:05 PM
our system is edwards, and it was not the cheapest, but we choose it because the marine grade steel they use which seemed us the most durable.
It costs 4600 less 700 rebate. But you remind me that they have forgotten the warranty booklet, have to call them tomorrow., so I don't know the exact specification

gardenlen
29-08-2007, 04:23 AM
thanks hedwig,

what size tank does that come with?

len

DirtyDave
16-09-2007, 07:52 PM
Hi Guys,
I am a plumber in the Barossa Valley,SA
Cosmic , I haven't seen your heater in SA but i would imaging the sytem has two elecric systems or circuits, the first is a sensor that detects that the water in the panel is hotter than the tank it will then turn the pump on to circulate the hot water to the tank, second the tank itsself should have a thermostat that operates the gas valve, It sounds like the system my not be commissioned properly, from what you are describing the thermostat in the tank is set to high and is allway trying to top up the temprature when it doesn''t need to......

Solar hot water sytems aren't that simple a good solar dealer has to take into account water usage summer and winter temps min and maximums frost pron areas,
in the past year some of the bigger manufacturers have been bought and sold, I am not sure what is good anymore,, when i alway purchase anything, back up service is always my priority.

Cosmic
28-09-2007, 03:52 PM
I am hoping summer brings a lower bill. Already we only need to turn the hot water tap only slightly on and the water is damn hot. What is the average gas bill for two people using it for water and stove(no oven)? I cook a lot. I cook chickpeas, dried beans etc. They use a bit of gas.
What does your bill come to?

DirtyDave
28-09-2007, 05:10 PM
Cosmic, Have you asked the installer, if the unit was commissioned to manufactures specification, If your not happy :( make a warranty claim and advise the installer you are doing so, because the manufacturer will send a service agent out and if installed incorrectly they will charge you for the call, it is then up to you to try and recover that money from the installer,
:idea: Send me the exact model number and i will run you thru the settings, :D
There must be a separate setting for the Gas thermostat, as it is only a boost, and would be set at about 60/65c and your solar should be getting way hotter than that. Another thing to be careful of in fitting solars to newish existing houses is to make sure there is no plastic pipes getting super hot water, make sure a solar approved tempering valve is installed, ( Mixes hot and cold water together to a safe temp about 50c ) Solar hot water can get very hot and Dangerous. :shock:
In South Oz i recommend roof models over split systems, because there is so much less that can go wrong with them , no pumps or computers,,
The Roof model here in South Aust I have customers that turn the power of to the unit completely for most of the year, if you spread your usage over the day on the days with less input you can still get enough hot water,,,.

Cosmic
02-10-2007, 03:25 PM
The thermastat dial is locked in the the highest setting with a rivet. Even in the instruction manual it has a picture of it with the rivet in place. They call it a 'fixed thermastat control'.
the system is Dux sunpro gas 305.
It says in the manual winter may give a higher gas bill.
The house is old with all copper pipes.
I really don't think it's installed wrong. I think it's just he way it is.

DirtyDave
13-10-2007, 09:27 AM
Sorry Cosmic for the late response,
I have looked at your heater and don't think much of it,
I feel you've been done buy good marketing,
Your tank only holds 170 litres, even though the model is called a 305, which is its potential output on a good day, Basically after a few showers your unit reverts back to being a normal gas hot water system, as the solar input cannot keep up with demand,
The thing with solar is to heat and store enough hot water to go the distance, having a large storage tank means during the day the sun can heat up enough water for your evenings needs, having a large storage means your storing heated mass your not wasting water as you only use what is required ,solar its free after all. some of the bigger units can go days with out any solar input, because of the larger volumes...
Cosmic if you have low hot water needs you should be OK, If you have teenage girls that love long showers, your not going to be saving much at all,,
Try and keep your hot water usage to daylight hours mate...

shefplumb
17-10-2007, 02:11 PM
Hi there,
Just joined the discussion & like Dirty Dave i to am a plumber in Adelaide focused on plumbing sustainability & a registered Eco smart plumber.
The DUX sun pro is not a stainless steel at all and all solar units installed after November 2005 must have an approved solar tempering that allow the supply of hot water not to exceed 50 degC
I do have a vested interest in solar units but Dave you might want to check out our units using Evacuated tube technology as it is an ideal system for frost prone area's not to mention its high efficiency

Happy to give you more information on our system if you require as there have been a few installed within that region in the last few months
Feel free to check out the web site at http://www.hillssolar.com.au
or contact directly via email for further information

Regards javascript:emoticon(':D')
Very Happy

gardenlen
17-10-2007, 02:43 PM
g'day shefplumb,

this system does it actually heat the water by the sun?

if so can it be coupled with a normal hotwater system?

to me the costs of these other solar h/w systems with their small tanks is prohibitive.

my thoughts are is it possible to run a normal system with a solar collecter type system even if it entailed using batteries?

in round figures what does one of your preffered systems cost installed and what capacity is the tank?

you can send me a p.m or e/m if you preffer.

tia

len

shefplumb
17-10-2007, 11:49 PM
Hi Len
Yes it does heat the water as it circulates through the manifold & does so through heat transference.
Yes it can be coupled up with your existing hot water service - its called a retro fit kit and dependant on what type of hot water service you have there is a kit specific to its requirements
Not to sure what you mean about the batteries? please do not confuse PV with solar hot water as they are two separate animals if that's what you may mean - sorry taking a bit of an assumption there
Cost of system varies dependant on what you require ET come in different configuration from 10, 22. 30. 40 tube units - retro fit kits - complete systems & optimisation pitching frames. storage tanks in a split arrangement are 160Lt, 250Lt & 315Lt stainless steel tanks with polymer outer casing

As a virgin to the forum format not to sure what p.m or e/m mean
but check out the Hills web site http://www.hillssolar.com.au
or for pricing on your requirements send me an email at shefplumb@adam.com.au
As far as installation cost that would be up to the local plumber & what you require doing - but you get some rather healthy rebates back
REC's currently at around $32.00 per point
Federal rebate on principle place of residence having a household income of less than 100K @ $1000.00
Plus i think there is a state rebate available in Brisbane - check with local

gardenlen
18-10-2007, 04:57 AM
sent you an e/m shefplumb,

len

DirtyDave
18-10-2007, 07:55 AM
Shefplumb,
I have been looking at the evacuated tube system and it looks great
looking at a solar system for myself, as I don't like the split system personaly,
Just this week I have taken over as manager for the company I work for,
And would like to learn more, Haven't heard much of any actual field reviews of such systems,,,

one of my call today was to get my eco acreditation, but another plumber said it was just a big sales pitch for the solar hot water companies,,
Got to go to work now cheers

gardenlen
18-10-2007, 07:58 AM
for me those sort of acreditations are industry driven standards seeking gov' sanction and don't realy amount to much, consumers want all up front honesty and integrity above all else.

no feel good needed be above board.

len

shefplumb
18-10-2007, 09:16 AM
Len
Thanks for the message - it gives me a bit better understanding of the forum now - tia
I will send you you a pm later today about what you asked
Accreditations are just that, however it does mean that a business is trying to improve it knowledge about different product & idea's and improving it's service to its customers
Integrity comes back to the individual

Dave
I can understand some concerns you have about split systems but i think its a far better way to go for many different reasons
Not a push from hot water manufacturers at all - more of an industry push
you make it to what its worth to you & or your company - its a better resolve than a money making machine such as the ........................ no franchise licence here
will contact you via pm or e/m to discuss out of forum

thanks & TTFN

Cosmic
08-11-2007, 10:06 AM
Since the weather has been hotter our gas bill went down to $87.44 for two people showering as well as the stove. I spoke to my sister as she has a gas hot water system and her bill for one person was $125 without the stove.
The savings over the summer might be even more. At least it's not all doom and gloom.
The pilot light seems to go out sometimes when it rains. We don't realise until we go to have a shower and the water isn't really hot. On a cloudy day it dosen't get hot enough for me to shower in so I am a bit thankfull for the gas boost.
A government worker friend of mine said it's the law to have the system gas boosted to prevent some disease?

lance
14-01-2008, 10:46 PM
G'day,

I have an opportunity to install hot water on my house ..but am finding it difficult to work out the most efficient and reliable system.

It would seem solar/instantaneous gas boost is out as I have to get bottles of LPG delivered.

I am currently looking at solar/electric boost (split system) and a heat pump system (two QUANTUM systems, one with heat pump only and the other with panels to assist in evaporating the refrigerant).

It would seem the heat pump option would be "set and forget", but would be more complex in terms of control systems and machinery (i.e. shorter lifespan and possible breakdowns).

Is anyone out there able to offer any info,hard facts, or a link to a good comparison site?

Cheers. :D

Alex M
15-01-2008, 08:06 PM
Hi Lance,

Some solar hot water system information links for you:

http://www.woodworkforums.com/showthrea ... 950&page=2 (http://www.woodworkforums.com/showthread.php?s=5cbd65a1a7d8b62b7c7bc44beb98d644&t=20950&page=2)
http://www.solarshop.com.au/solar%20hot ... 20page.htm (http://www.solarshop.com.au/solar%20hot%20water%20page.htm)

....and an interesting discussion on hot water generally here:

http://www.woodworkforums.com/showthrea ... 950&page=2 (http://www.woodworkforums.com/showthread.php?s=5cbd65a1a7d8b62b7c7bc44beb98d644&t=20950&page=2)

Soleil.Lunar
17-01-2008, 07:27 AM
We have a solar hot water system with two back up systems. In winter the water runs through a jacket on the wood stove for extra heating. When the wood fire isn't on (summer) there is an electric booster for cloudy days, we keep the electric booster off (we just cut the power to the booster by switching off the hot water system on the electricity distribution board), if we realize we have run out of hot water we turn it on for two hours after which there is a tank of hot water to use, then it is turned off again.

The "computer" on your gas system is most probably a thermostat. The thermostat will most probably only tell the booster to kick in at a certain temperature. Can you adjust the thermostat setting so that the booster doesn't kick in so often?