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Thread: Solar Hot Water Issue

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    Cool Solar Hot Water Issue

    I've recently had a solar HW system installed. Its the flat collector with roof mounted tank. I had a few concerns right from the start as the only available north facing roof space was at the opposite end of the house from where the electric hot water was installed. The original HWS was located under the house off the garage & was fairly close to the bathrooms with the kitchen being the longest run. The new one is above the kitchen with the bathrooms being the furthest away. The water temp in the bathrooms is just right with NO cold water mixed in but this means that all the water used is hot water & I'm running out.
    Ive turned the hydrostatic mixing valve at the tank completely off & adjusted the thermostatic temp control right up but with very little noticable difference. I seem to recall that legislation required a limit to how hot the thermostatic temp control would go. Is this correct ? I realise that things will get better in summer but how do I get the temperature up right now ?



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    I believe the max temp of hot water is no more than 65C, it could even be lower and from what other members have posted, no plumber will alter the settings due to the option of being fined or even sued by the customer.
    I am wonder what area you live in because if your having problems now, what will it be like over the coldest months ahead.
    I think thats why most Solar HW systems have some kind of 'Booster', electric or gas to overcome shortfalls in heating.
    But that sort of overcomes the whole concept of Solar heating, doesnt it?
    Are all the pipes going IN and Out fully insulated, very much so the Hot from the tank to the tap.
    You may not think the IN cold water pipe needs to be insulated but exposure to the atmosphere can make that water colder and that means more Sun heat is needed.
    Idealy a thermocouple in the tank to tell you just how hot that water is to see if your loosing heat along the pipe.

    In my area I think the 'Evacuated' tube type are the only viable option for Solar HWS systems.
    They seem to be successful in the northern climes but I am going to wait and see.
    Last edited by gordon_s1942; 21-05-10 at 10:55 AM.
    I stand unequivicably behind everything I say , I just dont ever remember saying it !!

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    The evacuated type is the way to go. They are about 40% more efficient. Unfortunately the tank needs to be close to the collectors. I didn't want a roof mounted tank but I had no choice really.

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    Is it gas or electricity boosted? I assume its electricity?

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    what brand
    woteva

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    Rheem

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    so that would have to be a hiline 52S160 or 52S300
    woteva

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    Get your plumber to remove the mixing valve from the tank and install it in the roof or under the house (where ever your pipes go) down the other end of you house near the bathrooms. Kitchen and laundry don't have to have tempering.

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    Cool

    But the mixing valve is turned right off.

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    Quote Originally Posted by watchdog View Post
    But the mixing valve is turned right off.
    Didn't think you can turn them off? Only turn them upto max temp which is 55???. I could be way off the money. I will have to check my facts.

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    Junior Member moke007's Avatar
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    Quote Originally Posted by watchdog View Post
    thermostatic temp control right up but with very little noticable difference. I seem to recall that legislation required a limit to how hot the thermostatic temp control would go. Is this correct ? I realise that things will get better in summer but how do I get the temperature up right now ?
    This does seem not right, the minimum water temp in the tank is supposed to be 65 and normally the thermostat allows you to adjust it up to about 80. The reason for the minimum 65 in the tank is to stop bacteria growing. So if you have turned the thermostat right up and the water is not getting hotter it seems the booster may not be working or something???

    The max temp allowed to be delivered to a bath / shower / hand basin is 55 hence the tempering valve.

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    Quote Originally Posted by moke007 View Post
    So if you have turned the thermostat right up and the water is not getting hotter it seems the booster may not be working or something???
    This would be my call...

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    Cool

    Pulled the fuse on the OP feed & took a reading towards the tank. 40 ohms so the cabling & element are ok. Rang Energy Aust to get the OP switching checked out. Turns out to be a faulty OP tone receiver in the meter box. I've never heard of one going faulty but they say its reasonably common. They bypassed it to give me permanent power at OP rate until it's replaced in about 2 weeks.
    Thanks for the I/P everyone.

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    Quote Originally Posted by watchdog View Post
    The evacuated type is the way to go. They are about 40% more efficient. Unfortunately the tank needs to be close to the collectors. I didn't want a roof mounted tank but I had no choice really.
    I have been looking at one of these on ebay he doesn't have cred for it yet says he is going through ther process will take 3 months.
    I need to put mine on an N east faceing roof saving my North fro PV solar(dont have much room)
    Any how at $1400 plus $1200 to install minus $1000 fed and $600 State and -$700 recs should be not to bad save me roughly $400 a year. Pay for itself in less than a year

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    Quote Originally Posted by Ramjet View Post
    Is it gas or electricity boosted? I assume its electricity?
    In the beginning of the thread they said it is "Solar Hot Water" so I think it will be in solar energy.

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    Just my two cents worth as an installer.

    Your tempering valve needs to go as close to your bathroom as possible.
    The tempering valve adjusts between two temperatures, you cant turn them off.
    Evacuated tube units........Ooooooo I'm getting shaky.......are terrible and what I mean by that is yes ok you might get hot water but the whole process is worse than other models. The way they are made, materials used, spare parts etc etc.
    Your Hot water pipes MUST be insulated to retain temperature to the other end of the house.
    An Option would be to install a circulating pump on your hot pipe, I did that at my place and works well, I have about 20+ between bathroom and solar.

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    Wink Tempering valve installations.

    G'Day Cobbers,
    This is what I checked out some time ago.
    The Plumbers are just taking the easy way when installing the Tempering Valve. It is only mandatory to connect personal hygiene outlets (bath, shower and hand basin.) to them and limited to 50 degrees C.
    Laundry, Kitchen recommended minimum 60 Degrees.
    Storage units 65 minimum, to avert Legionella Bacteria forming.
    The same applies for all types of hot water units.
    So the claim that they must install at the storage unit is a fabrication.



    Kindest Regards, " The Druid ".


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