Eco Alliance Dynaheat heat pump hot water system

I recently installed the the Dynaheat 315 litre hot water system for a family of 3 adults. We are constantly running out of hot water. Does anyone else have one of these? We were assured this hot water service was suitable for 3 to 5 adults, our previous off peak 360litre electric storage heater never ran short of hot water.
These hot water services are marketed as a cost efficient hot water system, could it be sleight of hand? Am I now only heating approximately 150 litres of water each cycle (& therefore the so called cost saving)? The thermistor (thermostat?) appears to be half way up the tank, all previous hot water services had the thermostat at the bottom and therefore heated all the water (not just the top half of the tank).


This site may be worth looking at - for other experiences (& Eco Alliance’s response(s).
EcoAlliance Dynaheat |


Ain’t that the truth.

Caveat Emptor.

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Welcome to the community @esahc.

As a new system it will be covered by warranty. Has the supplier/installer responded to your concerns. There may be a fault with the system, or it may not be set up correctly. Have you also looked for any signs of hot water leaking.

The savings in electricity with a heat pump HWS come from the technology (same principle as a reverse cycle air conditioner) used to convert the electricity used into heated hot water. Typically they use one third of the electricity to provide the same amount of hot water.

The internal location of the controlling thermostat for your system may be different to what is a simplified external diagram. It’s an interesting observation or question, as to whether a heat pump storage HWS is equal to a similar volume conventional resistive heater HWS. Hopefully the industry is not duding consumers by offering undersized upgrades. One of the Choice team may be able to comment on the technical concern. @BrendanMays.

315l Dynaheat?
Their web site has a 155l and 215l, but no larger model. Perhaps yours is not listed?


Comparing capacity is not always a 1:1. I once replaced one gas storage HWS with another of the same capacity but the new one’s performance fell far short of the old. It has to do with burners and insulation, not just capacities.

Bottom line is (say) 300 litre of this one cannot be readily compared to 300 litre of that one. One has to look at rate of recovery (sustainable delivery). Any claim for ‘suitable for 3-5 adults’ is no more than marketing based on an assumption.

For example, a particular Aquamax is specified to deliver ‘390 Litre First Hour Delivery with a 155 Litre Stainless Steel tank’. That reflects its capacity to heat water and the litres delivered includes a hot 155 litres from a full tank plus burner capacity to keep the continuously refilling tank at/near temperature until 390 litres have been delivered, but as there is more cold water introduced it will gradually be unable to maintain temperature, and hot would gradually become warm under full load.

How many people? Are 3 people taking showers concurrently? Is there a washing machine using hot and cold rather than just cold? Is someone doing dishes while another is showering? Is someone filling a bath or two baths concurrently?


Agree understanding this outcome is fundamental in assessing any HWS continuously supplied with gas or electricity.

I noted some Heat Pump systems are marketed as requiring a smaller storage capacity. The assumption is that they are always connected to the power supply and will commence heating as hot water is drawn off. I’ve noticed several product promotions (marketing hype) for heat pumps that suggest a smaller storage capacity to meet customers requirements for replacement of off peak storage systems. It’s an assumption that the heat pump system to achieve this may need to be connected to the uncontrolled supply. IE not connected to ‘off peak’.

In @esahc post the original system was installed to operate on ‘off peak’. It’s open to interpret which tariff and hours that may be. Each state has one or more options.

Comparing the storage capacity of an off peak resistive HWS to a an off peak connected heat pump storage HWS - it’s possible the true usable storage tank capacity of both systems needs to be the same, or possibly even greater for the heat pump option. This would make the off peak larger storage volume heat pump option a very expensive purchase in comparison to a lower storage capacity heat pump system connected as an uncontrolled load.

With a heat pump HWS using around a third of the power, it’s likely the savings in the cost of off peak electricity are less significant than those of the greater efficiency of the heat pump. Getting the benefits of both may not justify a larger storage capacity option.


When we replaced our POS 400 litre dual element Rheem with a 315 litre Saxon heat pump at our previous residence, we changed the off-peak Tariff 31 to off-peak Tariff 33.

We cut our hot water electricity usuage by 80% and our hot water electricity costs by 70%.

We very rarely ran out of hot water, and certainly no more frequently that with the Rheem when the second element was not turned on.

Ergon has some info regarding system size.


I did check the site, some posts do not instill any confidence in the product


Reading through the P/Review posts - it seems to me that the contracted installers are the cause of many of the problems encountered. Ecovantage advised me the delays for regional areas (& additional travel costs for living outside a 100km radius of the capital city…) are due to the sourcing, training and accreditation of installers.
Installation is due by the end of October: the initial contact with them was early July…


@mark_m, thanks for the welcome. sadly the location of the thermistor (thermostat?) is exactly as shown on the diagram, although I do not know what goes on inside the tank (extra long probe perhaps?). I did contact the supplier on a number of occasions and eventually got a response after posting concerns on one of their FB adverts.
I had 2 concerns. insufficient of hot water for 3 adults and almost no water pressure (the hot water service was near useless). A plumber did attend but would not/could not answer questions on amount of stored hot water. As for lack of hot water pressure (we are on a rural property with only tank water delivered by a pump) he said he could not help, and left.
The pressure issue was the thermostic valve. We have fixed that issue.

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Could you explain that a bit, I think of thermostats as controlling temperature not pressure.

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@PhilT, there are 3 adults showering over the space of 3 hours (not concurrently) and we ensure that dishes and clothes are not washed until after everyone showers. We have a spa bath (soon to be removed), it is not possible to fill it to any usable depth as there is insufficient hot water.
The recycle time is roughly 3 hours. The heatpump runs almost continually all day if anyone uses hot water (it also come on for much of the night when no one is using it, I suspect the insulation is not very good around the tank)


@mark_m, the hot water service is not off peak, it can (and does) operate all day.
I apologise, my original post is wrong. The hot water service has a capacity of only 215 litres (I have been angry for so long I neglected to look), I never received any documentation or instructions from the supplier. So potentially with the thermostat half way up it is only heating 100 litres of water. This is a third of the hot water we had at our disposal with the old Vulcan off peak mains pressure hot water service (which I might add worked flawlessly when it was replaced).


Did the plumber check the temperature setting and outlet water temperature?

Assume by

Assume you are referring to the tempering valve?

The storage tank volume will be on a serial number plate or label attached to the tank. Per the specifications the 215l tank is 181cm tall x 51cm in diameter. The picture of your system suggests it is this size or smaller.

Note the Eco Alliance web site is big on marketing hype, and not too great on technical content. The best I could find.

Based on the 215l tank size and data, the system should be able to heat 215l to 55C every 2.5hrs. It sounds as if your system is connected to the unregulated power supply to the house and is not on off peak as before.


@syncretic, you are correct. However, the tempering valve had so much resistance to water flow that it restricted hot water flow by 50% on my pump driven system.


Ah thank you.


Thanks for that. My previous post and your details overlapped.

In respect of resolving your concerns with the purchased heat pump HWS. The responsibility for any remedy or warranty is firstly with the supplier/installer. In your instance was it Eco Alliance of Melbourne from whom you purchase the HWS? Was the installer also provided and paid for as part of your order on Eco Alliance, or did you choose the installer and pay separately?

If the unit you have purchased is not operating correctly, as a consumer you have rights under the ACL (Australian Consumer Law) to remedy at no cost. It’s not evident from the discussion so far whether the system is defective, or whether if there is a defect it is a major or minor defect.

Alternately the product may be performing as designed and is not defective. You may still have rights under the ACL to remedy depending on the representations made by the supplier as to the suitability of the chosen system for your requirements.

It’s important that any communication with the supplier is formal and in writing (EG written correspondence, email). Personal recollections of phone calls and verbal responses from Eco Alliance will have little value in perusing further action through your State’s Office of Fair Trading, or in you personally asserting Eco Alliance needs to comply with ACL.

There are differing recommendations on system sizing for heat pump HWS.
Choice in the guide I linked previously suggests 50l per person per day. More if the family like longer hotter showers, or you wash clothes often in warm or hot water. I’ve read in competitors material recommendations a 170l heat pump stored capacity system not on off peak power is adequate for a 3-4 person household.

Some very basic fault finding if you can. I’m not an expert on these types of systems. If there are others out there please feel welcome to offer some alternatives.

  1. Choose a day you can go without hot water from early in the morning EG 8 or 9 am.
  2. There should be an isolation valve on the pipe leading from the HWS to the house.
  3. Close or turn the valve to off for at least 8 hours.
  4. The hard part is to then observe the system for those 8 hours and carefully note when the system turns on and off, outdoor unit compressor running noted by the sound made by the unit.
  5. It should run continuously for a period of time to reheat the water used in the morning. Anywhere from minutes to several hours.
  6. For the rest of the day it should not come back on, or do so only once or twice briefly to make up minor temperature loss.
  7. The system running for more than approx 2.5 hours initially or cycling frequently after that time is an indication the HWS has a fault or defect. Don’t forget to open the isolation valve after the 8 hours is up.

For your old system, you could clarify what the daily hours of service your off peak tariff provided? Are you able to advise the approximate power used per day by the old system, kWh per the previous billing? It will offer a guide to how much hot water the old system was providing on a daily basis and timely reheating capacity.

It’s important to consider there is a possibility your household has a leak in the hot water piping. If the above strategy suggests the HWS is not faulty and there is a significant leak. A similar strategy of not using any hot water taps for 8 hours should see the heat pump cycling frequently and for longer periods to make up for the leakage, after it reheats any morning consumption.

Not all plumbers are motivated to meet a customers needs in the same way. I’ve had plumbers turn up and find no fault, and the next point to something that was readily apparent, and remedy in 30 minutes. When you find a good one, a little praise goes a long way.

P.S We are on an in ground tank with a house pump. The old system was electric. The newer is instantaneous gas, pending an upgrade to solar - direct heating or indirect with solar PV. Either require a new storage tank.


@mark_m, I should confess that I got this hot water service at no charge due to State Government “incentives”, I did not even have to pay installation, so I do not really have any right to complain.
It is my own fault because “you get what you pay for” and “if it is too good to be true then it almost certainly is”.
However, in my opinion the State Government is paying for a sub standard product being installed into peoples houses.
I do believe the hot water service is working within specifications, and I know we have no water leakage (the pump does not come on to start with), it is just the limited amount of hot water in storage which is my issue. We have only had one power bill since installation and it was not full term, so after the next invoice I should be able to gauge any savings. I will be surprised if they are not significant, after all, we appear to be only heating one third of the water we used to :slight_smile:
I will continue to save for a suitable replacement, I understand the life expectancy of these units is about 6 years based on user group comments, so before that time I expect to bite the bullet. Sadly my choices are limited to solar or electricity, gas bottles would be too expensive and I have lost faith in heat pump.
Many thanks for your time.
One other thing (sorry) . . . . .
This unit heats water to 61 degrees, I was told and have read that water stored below 60 degrees can breed bacteria (& our water is untreated). If I am right and the tank is only heating the top half of the water, then the water below the thermostat is or could be a breeding ground. (The 3rd person to shower within a 3 hour period does not require cold water mixed with the hot water)


Yes you do have a right. Check the government program documentation and it should say that you are the owner even though it was purchased as part of the program. As a result, you have the same rights as if you bought it using your own money. The only difference is the government may make the purchase decision for you (such as the type and provider of the system being installed).

It is worth providing feedback to the state government program team as they should be aware of the challenges a provider in their program is causing.


In respect of having rights to seek remedy in the instance the unit is faulty or not fit for purpose.

There is an opportunity to gain assistance with resolving your product concerns by following @phb recommendation to contact the Govt program representatives. That would be in addition to contacting formally the supplier Eco Alliance.

A summary of key points from the previous posts:

Noted the correction and posted copy of the name plate. Storage capacity is 215l.
Operating and basic instruction manuals should have been supplied to the owner, as well as details of the warranty provisions. It’s important to request and insist on a copy of these from the supplier to ensure all owner obligations are able to be met.

The heating capacity and storage volume are similar to other products recommendations and general guides for a household with 3-4 occupants.

Heat Pump hot water systems are well established products. The technology used is not slight of hand. Similar to reverse cycle air conditioners they deliver 3-4 times the hot water for the same electrical energy compared to a basic electric resistive hot water service.

Noted this was subsequently amended to 100l by the OP.
There is no evidence this is how the unit is intended to perform. The individual HWS supplied to the OP may appear to behave this way because it has a defect that requires a repair. We don’t know all the facts.

It’s up to the OP (@esahc) to follow up with the Govt Program and Supplier.

It will help all if the responses/resolutions to formal approaches by @esahc to both are able to be shared.

The discussion suggests the HWS installed most likely has a fault that requires a repair, IMO. There is no conclusive evidence the product design is defective, is of poor quality or not fit for purpose. If it is not faulty it may simply not meet the needs of the individual household which are greater than typical for the number of occupants.