Should I Replace My Solar HWS with a Heat Pump?

Lhelpme on 25/04/2021 - 13:53
Last edited 25/04/2021 - 16:42 by 1 other user

Hi everyone,

We were referred by a friend about government rebates on heat pumps which we were quoted $499 for a full installation of a twin system by eco alliance. Their compressors are Japanese made by Toshiba. Our current system is a solar HWS gas boosted which is around 12 years old and seems to be working just fine. Our gas and electricity bills aren't bad either ($80 in summer for gas) and we have solar panels.

The only problem with our current system is that it takes forever to get any hot water, especially from the taps. The only place that gets decent hot water is the front shower (closest to the system). We've been told by a previous plumber that there's not much that can be done while the people looking at doing the installation here said it might help and that it is a solar problem.

Is it worth replacing our system with the heat pump?

Many thanks

Edit: It seems there's a general consensus that the heat pump won't solve the hot water issue. Is there still any other benefits in replacing it?

Home & Garden Solar Energy System

Comments

  • loulou1 on 25/04/2021 - 14:18
    +4

    Not sure how a heat pump would fix the issue? The cold water that is already in the pipes needs to move through before the hot water will come out regardless of what system is used to heat the water that is not yet in the pipes and on its way down to the tap.

    • helpme on 25/04/2021 - 14:40

      yeah that's what we thought and was told previously as well. Thanks

    • akyeeeahdude on 25/04/2021 - 15:25

      If the OP's tank is mounted on his roof (that his solar HWS heats), then installing a heat pump HWS would get hot water to the various taps slightly quicker because the heatpump can be mounted closer to the house. Naturally this depends on where the OP decides to mount it though - I'd recommend mounting it close to the bathrooms.

  • afoveht on 25/04/2021 - 14:25
    +5

    Solar is not the problem.

    You either need to either re-position the heater / plumbing to be closer to all outlets, or get extra heaters near the specific outlets (most often done with on demand heaters like an Infinity or similar), or have a proper recirculation system which involves properly insulating all the pipes too.

    • helpme on 25/04/2021 - 14:40

      Cheers

    • Extreme on 26/04/2021 - 08:03

      This.

      The location of the hws is important. Because you need to flush the cold water that’s in the pipes out before hot water will come through. The longer the pipes, the longer this takes.

  • [Deactivated] on 25/04/2021 - 14:32
    +1

    Heat pump would be free to run for you compared to your current gas! But is Eco alliance a reliable pump that will at least last you 10 + years? Cheaper might cost you dearer over the long run.

    • helpme on 25/04/2021 - 14:38

      But is Eco alliance a reliable pump that will at least last you 10 + years? Cheaper might cost you dearer over the long run.

      Yep, that's my concern as well. I actually told the guy we were hesitant with anything related to government rebates and incentives after getting shitty light bulbs and showerheads but the guy (I know he's a salesman) was quite adamant that this was a good, expensive, and well-made system that the government was providing large subsidies for. I'm just curious as to what the savings will be though.

      • [Deactivated] on 25/04/2021 - 14:50

        Eco :
        https://www.productreview.com.au/listings/ecoalliance-dynahe…

        During my search i short listed Istore & Hydrotherm but never went ahead with any. I end up servicing my old system and replacing my intank heat element & thermostat for less than $200.

        • helpme on 25/04/2021 - 15:27

          Cheers, I'm surprised our plumber never mentioned this.

  • Elppa8 on 25/04/2021 - 14:49
    +1

    Part of the problem could be the tempering valve as it mixes cold water with the hot as it leaves the HWS at 45° to 50° instead of 60°+ and the furthest taps from the HWS don’t get as hot as the one closest. If they go faulty they can mix more cold water than normal.

    Also consider the location of a heat pump system for noise reasons when running at night.

    • [Deactivated] on 25/04/2021 - 14:51

      That's very true, they need to be replaced every 5 years apparently!

      • onetwothreefour on 25/04/2021 - 15:48

        I just replaced mine a week ago as a lot of water was leaking from it. I didn't know but you have to open the valve once every 6 months and it should last longer.

    • CheapSticks on 25/04/2021 - 15:16

      I think that cud be the problem otherwise i dont understand whats going on…ofcourse when you open tap for like first 15-20 seconds u get cold water but after that its fine…ur tempering valve must hv gone bad - cost $200 but worth replacing it…

      • helpme on 25/04/2021 - 15:26

        ofcourse when you open tap for like first 15-20 seconds u get cold water but after that its fine

        Yeah we're talking like 5-10 minutes here

        • onetwothreefour on 25/04/2021 - 15:47

          5-10 minutes before you feel hot water? Something's not right there or your HWS is 1km from your house!

          I'd be having a lot of cold showers waiting for that hot water to come.

          • helpme on 25/04/2021 - 16:14

            @onetwothreefour: yeah we don't use hot water at the back of our house, tbh 5 minutes is probably the most I've ever waited and it starts to get warm. Everyone just showers at the front during winter, summer is ok, which takes 2 mins or so but we have a bucket to catch the water for the garden and stuff.

    • akyeeeahdude on 25/04/2021 - 15:29

      Many models now are very quiet. Even very close to the window of a bedroom, it can be very difficult to hear them. I had one of the first model Rheem MPI-325L heat pumps that was mounted basically next to my daughter's room and it never bothered her over the 7 years she was in the room (or when we'd be lying in bed with her to put her to sleep/reading a book and we'd never hear it in operation). The Rheem HD-310 was an alternative model available at the same time and it was a decent amount louder, hence why many builders provided the MPI-325 instead.

  • akyeeeahdude on 25/04/2021 - 15:26

    I had a Rheem MPI-325L heat pump last from 2009 to mid 2020. Replaced with an Enviroheat 250L Heat pump HWS and I've been very happy. Cost was $2490 but it would be cheaper for you as you're in Victoria and get the sweet VIC Gov rebate.

    • helpme on 25/04/2021 - 16:15

      yeah this is a 310L dual system. Just wondering what the main benefits of getting installed are.

    • CheapSticks on 25/04/2021 - 21:53

      hi - $2500 seems pretty good price..how long is the warranty on this?

  • highon2str on 25/04/2021 - 17:03
    +1

    We have rooftop solar and recently had a 300L Sanden Heat pump HWS installed to replace a 10yo Gas boosted solar HWS. Apart from the initial cost of the system, it runs whisper quiet and costs almost next to nothing as we have it on a timer to only run during solar production hours. No tank anode to replace either. Hot water is super hot and seems to arrive much sooner (maybe because it's hotter?) than it did with our old system.

    Definitely recommend a good heat pump HWS especially if you have solar and are intending to live on the property for the long-term (till you reach the break-even point and recoup your initial cost)

    • JIMB0 on 25/04/2021 - 17:22

      How much do they cost?

    • helpme on 25/04/2021 - 17:41

      Thanks, that's reassuring although a Sanden is also considered pretty much the gold standard. Any reason why you decided to switch? Was your gas bill expensive? Ours is cheap in summer and really expensive in winter ($300-$400) but we had always assumed it was due to having a gas heating system that is on consistently.

  • highon2str on 25/04/2021 - 18:34
    +2

    Old system was due for an Anode rod, decided we didn't want to pay over a dollar a day for gas supply charge because we hardly used gas. We have reverse cycle heating for the home and induction stove top, so decided @JIMB0 to drop $4700+ on a 300L Sanden system and disconnected our gas supply. Yes @helpme gas bill was ridiculous. Upgraded to 10kW solar and electric everything!

    • helpme on 25/04/2021 - 18:47

      I see, well in our case ours is still working and we need to keep our gas anyways. I'm surprised your gas bill was high, we only have two panels for our solar HWS with 4 people and summer is just slightly more than the gas connection charges.

  • Waltervp on 26/04/2021 - 09:04
    +2

    I personally have a problem with gas. I think we are getting ripped off. I changed my gas heating to electric when I went solar and picked a heatpump model as well, with the rebates. I am super happy not to receive a gas bill any more and don't notice extra consumption in electricity. I am in Tasmania with west facing solar panels and with my pensioner elec discount have virtually no electricity bills any more and eliminated the gas bill (I only had hot water on gas).

    I'd say go for it.

  • peteraaa777 on 26/04/2021 - 09:59
    +3

    I installed a Hydrotherm heat pump to replace my 12 year old gas tank system, and I love it. It only runs for about 90 minutes each day (2 person home), and since I have solar panels, the running cost is very low. In fact, since the gas hot water was my only reason to have gas, not having to pay the gas supply charge more than covers the cost of running the heat pump. The heat pump is also very quiet, and since it only runs in the day time, it doesn't disturb anyone. I also see the cost of installing the heat pump as close to zero because my gas system was probably due for replacement in a year or two anyway, and I had a gas leak in the old rusty pipes in my house, which would have been costly to repair. As to waiting for hot water to travel from the hot water heater to the shower, this YouTube has a solution: https://youtu.be/KdA_gfau1s4

  • munecito on 26/04/2021 - 15:26
    +1

    What you need is a water recirculation system. It gets connected in a way that the water that is in the pipes goes back to the hot water instead of being wasted.

    http://www.pumppower.com.au/wp-content/uploads/2017/06/Comfo…

  • moar bargains on 26/04/2021 - 17:06

    Probably also worth checking/estimating lifetime and annual running costs to compare.

    https://www.sa.gov.au/topics/energy-and-environment/using-sa…

    That website is from SA government, but nothing there is SA specific (except perhaps default energy prices). You can also set the purchase price of your current system to $0, to enable you to compare.

  • thardy456 on 27/04/2021 - 09:16
    +1

    There is a slow but growing movement to get off gas. There is even a FB group: 'My Efficient Electric Home' dedicated to doing this. The cost of being connected to gas without any usage charges is approx. $2,500 / 10 years not to mention the savings and environmental benefits. We switched from gas ducted heating, gas hot water and gas stove to being fully electric with solar and we are saving around $1,600 / year.

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