thread: Desperately need hot water system advice!

  1. #1
    Registered User

    Aug 2007
    Sydney
    1,691

    Desperately need hot water system advice!

    OK, so we have a ye olde gravity fed tank in the roof on off-peak 2 electricity. The water pressure in the main bathroom is just fine for us because it's right underneath the tank, but we've got no hot water pressure at all in the new laundry we've built at the back of the house, it's just too far away. So we need a new hot water system with mains pressure. I've been researching and getting quotes but I am just so thoroughly confused.

    We would LOVE to go solar but we're on a south facing slope with big trees to the north and EVERY consultant we've spoken to agrees that we don't have enough solar access so that's out unfortunately.

    Heat pumps? I've heard baaaaad things about them, like they are unreliable, they cost a fortune to get fixed, they don't actually save that much power, $$$ or green house gasses? But they are by far the cheapest option because of all the govt rebates? Like around the $900 mark (with rebates). But we can't use off peak 2 electricity with them so running costs will probably be about the same???

    Gas tank ? We've got gas to the house right where the tank needs to go? Around the $2000 mark including the $300 rebate?

    Instant gas ? Around the $2200 mark with rebate?

    Any comments? Particularly, how did you decide to go heat pump / gas tank / instant gas and are you happy with your decision?

  2. #2
    Registered User

    Aug 2006
    On the other side of this screen!!!
    11,129

    I thought instant gas was the next most energy efficient way to go? It's often used as the booster system on solar HWS. Maybe research the exact cost/L of hot water of each of the models you're interested in and how much that will cost you over a year. Then think about things like - how close the unit is to where you use the most hot water. You could think about installing a small instant HWS right near the laundry/kitchen rather than replacing the one you've got...you'd still have the off-peak water (if you think that's the cheapest for you) but also wouldn't be wasting all that water going cold in the pipes on the way to the kitchen/laundry.

    Another alternative is to forgo the hot water system reabate in favour of the roof insulation rebate, if it applies to your situation (just thinking laterally here, it might not be a good idea depending on everything else).

  3. #3
    Registered User

    Apr 2007
    in lactation land
    3,776

  4. #4
    Registered User

    Aug 2007
    Sydney
    1,691

    Thanks so much for that info Marydean and Dusty. I'll digest it after the kiddies are in bed.

    Just giving this thread a bump now to see if I get any more hits

  5. #5
    Registered User

    Jun 2008
    in the eye of a toddler tornado
    2,450

    I'll be back with answers Rach, wriggly toddler on me atm

  6. #6
    Moderator

    Oct 2004
    In my Zombie proof fortress.
    6,449

    We got a heat pump installed at the start of the year. We did originally want a gas boosted solar system, but we are on bottle gas plus in a shady area. It is not doing to bad so far, but hard to tell about cost savings as we don't have past years in the house to compare. Our last elec bill was huge, but I was using our dryer a lot and the electric column heater. Have cut back on those, so we will see next bill how it goes. Have not run out of hot water at all since it has been installed.

  7. #7
    Registered User

    Jun 2008
    in the eye of a toddler tornado
    2,450

    OK back.... we had a broken electric HWS which was costing us a fortune in electricity, gave us 2 minute showers and we had to wait at least 30 mins in between, it took 90 mins to half fill the bath.... anyhoo we got the instant gas, we figured it only heats water when we are actually using it and it never runs out. this is lame but we literally get out of the shower every morning and say "I love this water heater" .... go for instant gas you'll never look back. it was a bit exy but we had to get an indoor one (we live in an apartment) and I'm pretty sure the outdoor ones are cheaper.

  8. #8
    Registered User

    Aug 2007
    Sydney
    1,691

    Astrid and Pixie, thank you both too.

    I like the idea that instant gas only heats what you need. But, it has to use a lot of energy to do it because it needs to heat it really quickly, whereas with a tank it can use less energy because it can do it more slowly. So I actually think that tank gas would probably be more efficient with less running costs than instant for us. Astrid that's good to know that you're happy with your heat pump though.

    this is lame but we literally get out of the shower every morning and say "I love this water heater"
    I say that about my washing machine EVERYTIME I do a load of washing (at least once a day). Ahhh, the simple pleasures.

  9. #9
    Moderator

    Oct 2004
    In my Zombie proof fortress.
    6,449

    Ok, back with more info now that I am not being harrassed by a small one.

    The heat pump is noisy, I was surprised by it, but am used to it now. So don't go putting it outside a bedroom window. It blows a lot of cold air when it is working, pity it can't be harness to blow inside the house during summer.

    My gut feeling is that it is using less than the old electric off-peak. Next bill should show if this is true.

  10. #10
    Registered User

    Aug 2007
    Sydney
    1,691

    Y'know Astrid (actually you probably don't want to know this), I have read or heard somewhere that you can actually get combined hot water making air conditioning units. Sounds logical to me.

    The thing we (especailly DH) likes best about the heat pump is that with all the rebates it's $900, so much cheaper than the other options.

  11. #11
    Registered User

    Dec 2005
    5,951

    We have instant gas and love it. Certainly a lot cheaper and more convenient than electricity.
    If the heat pump that Astrid is talking about is anything like our heat pump for the solar heating for our pool, then yep, it's noisy.

  12. #12
    Moderator

    Oct 2004
    In my Zombie proof fortress.
    6,449

    The thing we (especailly DH) likes best about the heat pump is that with all the rebates it's $900, so much cheaper than the other options.
    That was one of the main reasons we went for it. DH just went looking one day for the continuous flow units and was told about the heat pumps with the rebate. He did some research and the model (Stebel??) we got it meant to be one of the best, theoretically meant to only cost about $100 per year.

  13. #13
    Registered User

    Feb 2009
    90

    dh has been looking into this for us and he keeps talking about instant gas hotwater systems. we too would love to go solar, but for now instant gas is second best. dh is very passionate about saving water, power, reducing greehouse gases...all the good stuff.