5 photos
Quantum Energy AC4 Series

Piece of cow manure

Purchased unit in Nov 2015 now May 2019 the compressor dies of course only two year warranty what a waste of money and time. Would never recommend this product to anyone

Purchased in November 2015 for $4,500.00.

Build Quality
Value for Money
Cleaning & Maintenance
Noise Level
Household Size 5 person(s)
Smells of GasNo
Temperature Consistency
Heating Speed

Biggest paperweight ever. It should be illegal to sell such a low quality product

Installed mid 2016. Started infernal noise late 2018. Out of warranty after 2 years. $120 for technician to tell me it will cost $1100 to replace the compressor which comes with a maximum 1 year warranty

Heat pump was the another dodgy choice made by the builder.

I'm having this piece of scrap metal removed today and replaced with something realiable and hence truly energy efficient in the long run.

I can't believe installation of such a piece of rubbish counts towards basix points. What a dumb box ticking exercise.

Purchased in June 2016 for $2,500.00.

Build Quality
Value for Money
Cleaning & Maintenance
Noise Level
Household Size 3 person(s)
Smells of GasNo


Sold to us as being a quality product 3.5 years after being installed compressor is dead $1100.00 to replace go with a quality brand quantum is not quality at all

Purchased in April 2015 for $3,300.00.

Build Quality
Value for Money
Cleaning & Maintenance
Noise Level
Household Size 5 person(s)
Smells of GasNo
Temperature Consistency
Heating Speed

One of the most efficient heat pumps

I've had the Quantum Compact 270 heat pump for almost 2 years and it's worked perfectly. I configured the inbuilt timer to come on during the daytime when it's the most efficient (the warmer the air, the less electricity they use) and when I'm generating electricity with my solar PV. At a COP of 4.5 (1 kWh of electricity gives 4.5 kWh of water heating), it's the second most efficient heat pump you can buy - meaning it has one of the highest rebates - I got $1200 back. It's pretty quiet at 48 dB (my aircon is 66 dB - 4 times louder) but I always run it in the daytime - I can't hear it then anyway. It works well when we have guests who shower a lot. It will take about 4 hours to heat up the whole tank from scratch but most days it only runs for a bit over an hour (when there's only 2 of us), using about 1.5 kWh of electricity, compared to 6 or 7 kWh for the old electric HWS. The tank seems to be very well insulated compared to other HWS.

Date PurchasedMar 2017

Don’t bother

After just over 2yrs old, just out of manufacture warranting the compressor is making such loud noises it’s unusable. Rang warranty and it’s pathetic of only 2yrs warranty. Refrigeration tech came to look and it appears it’s not worth replacing or fixing a compressor as it’s neqlry as expensive as getting a whole new product. Ironic thing is I never wanted this when building the new house 2yrs, 4 mths ago. I wanted an electric hot water system but building said we can’t in a new house and needed something Energy. Well after this expensive lesson I now need to completely rewrite etc to have electric one put in as I’d never get a heat pump again. Way too noisy!! Don’t bother, it’s not that much you save on power bill, way more expensive when you have to replace a whole until after 2yrs!

May 15th 20187 Update: Nothing but issues.

Died after not long after 2yrs old. Wouldn’t recommend a heat pump at all. Just look at all the bad reviews. Noisy and unreliable. Has costed us a fortune and it’s shoudn't has been costing us hardly anything but maybe some services in the first 10yrs but after not even 2.5yra it’s ceased up.

Date PurchasedDec 2015

Had mine for 13 years Fantastic!

Hi I've had my Large quantum heater for 13 years, sometimes does 10 showers a day and it's freezing here in winter. But you have reminded me to check it and get it re- Gassed suggested by a plumber years ago.
Looking at all the complaints wonder if different models have more problems??
Also only paid about 1400 a rebate on $5000,
really it's done well

Date PurchasedMar 2004

You would be a fool to buy one of these

Just over 7 and a half years old. Came highly recommended by an energy advising company. Would last between ten and twenty. A heath pump hot water system apparently is still a economically great system, but our Quantum system has completely rusted through, leaking everywhere. Was sold as a top brand. Do yourself a big favour, buy a different brand!

Date PurchasedFeb 2010

Not Happy Chappie

We purchased a 340L heat pump in 2011 cost was $5000 less rebates. After six year it has developed a gas leak and we are told it is not repairable. Expensive unit for over 6 years. We won't go back there again. Reviews were on the good side six years ago - now negative comments override the favourable ones.

Date PurchasedOct 2011

Works well but is noisy

Built the house 18 years ago and installed a Quantum 270 litre unit (not sure of the model number) in the new build. It worked well for 12 years then developed a leak so needed a replacement. Replaced with a similar model 270-AS4 at my cost (around $3,000 from memory) as this would fit into the laundry cupboard where the original was located. The old system had a passive radiator which was no longer made so needed to install a fan unit on the roof to replace the old radiator - no biggy. The new unit worked fine for 3 years then it too developed a leak. This unit was replaced under warranty after some minor delays in getting plumbers to site. Then about 2 years ago the unit failed to start and after getting the plumber/aircon guys (Platinum Hot & Cold) out, the control board was replaced. This was also replaced under the 5 year warranty (just), so any more issues will cost me. The unit works well for me, but is a bit noisy in operation as it is installed indoors in a cupboard in the laundry that doubles as a clothes airing cupboard. Overall I have been fairly happy with the limited contact I have had with Quantum and the product heats the water at minimum electricity cost. The plumbers I have spoken to however are not enamoured with heat pump products in general, but say that Quantum are no worse than the rest.

Date PurchasedMar 1999

inferred warranty

If you want a quantum product don't expect more than 5 years use out of it.. Ours started rusting within twelve months, and they won't even reply to emails or phones calls. They assured me it we would get ten to fifteen years use, out of the over four grands worth of heater, we got less than six years.. This is one Company I would steer well clear of, if you want a reliable honest deal. It definitely won't be from them..

Date PurchasedNov 2011

One word!.. DONT

Quantum is the most ignorant Co. I have ever had the misfortune to deal with, They don't back up their products, they NEVER return promised calls or answer emails.. I would use cold water before wasting money on their products. Treating customers who have spent hard earned money on their heat pumps, the way they do is nothing short of disgusting..

Date PurchasedNov 2011
1 comment
A quantum manager, of some sort rang, me seven weeks after my first contact, after reporting them to the ACCC, to tell me they would NOT do anything about the crap water heat pump they foisted on me.. I asked him "why had he rang then".. His reply made me chuckle.. "Customer relations" he said.. My advice to anyone thinking of installing a heat pump is to stay well away from these no hopers..

Quantum Heat Pump

Just received a letter dated 23/12/16 saying that my Quantum Heat Pump is now ten year old and that it might require additional service or replacement. When is is replaced, it will NOT be with a Quantum product. I have had to spend a fortune on repairs ---$247.50 on 5/4/13, $375 on 21/3/14, and $700 on 6/5/15. My previous off-peak service went 19 years without a call out

Date PurchasedSep 2007

Awesome investment, Highly recommeded

I had a gas storage hot water system. The gas bill was so high upto 300 dollar. I have get plumber to install the quantum heat pump hot water system. 270L. I am so happy. My electric bill does not gone high as I was afraid of and my gas bill gone low to 40 dollars. This product is very reliable and highly recommended.

Date PurchasedAug 2016

Not worth the money

First impressions were good. Good savings on power bill after an initial outlay of $4500.00 it had just paid for its self after 6 a d a half years.
We fisr noticed our water pump cutting in and out a short an regular intervals, thinking we need to replace our pump after 20 years (can live with that) we then noticed a leak in our heat pump. Need a new heater there goes the savings. Were too from here?

Date PurchasedJul 2011

How do I get Quantum to ring me back???????

I installed my current heat pump in November 2006 and have had relatively no trouble until I tried to order a top lid, which has badly rusted. After my initial ring to head office in Sydney, I was told the part was available and to just ring and order, simple really(really????).
I rang two days running and left the requested voice mail message with my query to order and the requested call back details - still waiting to be called back.
Subsequent to this I emailed the General Mangers P A and, guess what, still no response after approx. 3 weeks.
Would I recommend their after sales service, hardly.

Date PurchasedOct 2006

Just over four years and they are all falling like flies in a Mortein storm.

I have NINE of these units on my property and due to poor manufacturing and an abysmal component failure rate I'm down to two that still function. One is working, the other needs to be coaxed into working as I have been told by a technician that certain electrical components were not made weather proof from the factory. More over, just trying to get a tech to fix these things takes upwards of a month and last time (and very much the last time!) I was handed a bill for nearly eight hundred dollars. At least when they stop working you can tell by the flash and bang from the electrical part that isn't weather rated properly as it arcs itself into oblivion.

not happy!

Thought we would save money with the energy efficient model, it lasted 6 years and the tank burst, the initial cost was approx $4000, so what we saved in power we just lost in having to purchase another hot water heater, but certainly not another Quantum very poor product life.

Extremely Corroded after 3.5 years

Hot water is cheap and the noise isn't really an issue for us BUT we have it on side of the house under the eaves and out of the elements and have just had a technician replace the temp sensor saying the tank is on its way out due to corrosion. These units must have an issue with electrolysis as they require a sacrificial anode. The anode needs to be checked yearly as if this is completely gone, the tank will go in a matter of months. I have just had arguments with Qantum and they have now agreed to replace the tank under warranty as it is likely to begin leaking soon and has caused other parts to malfunction. The customer service rep says this type of corrosion is expected and seen on most of the units, which is ridiculous! Clearly a design fault with the unit as they are likely to fail just after the 5 year warranty expires. If you know your rights under consumer laws it's ok but I am sure a lot of people just accept the manufacturer's word and replace at cost. (reasonable to expect this unit will last longer than the 5 year at the price point).
All in all, efficient hot water but need to keep it maintained. Surely other suppliers have sorted corrosion issues on the tank.
I wouldn't buy one again.

great unit.....would support any progressive technologies

Wouldn't go back to gas storage, instant gas or elemental electric
This thing produces endless hot water for my medium size family
12 months on and hasn't disappointed us yet

Glorious hot water

We purchased a house in far east Gippsland not long ago. After settlement, we soon found that the electric hot water service was leaking. After some time on the internet researching replacement environmental friendly options, we came across Quantum Energy Technologies great offer. In this, they supply and install your new heater then claim the rebates currently available from the Federal and Victorian governments. All you pay is a small amount direct to Quantum. Such a good offer that we purchased a second unit for our Melbourne address.

This action was in the first few days of January during the Christmas break,and yes you can probably guess what happened next. We turned on the old unit on arrival on a Sunday night and anticipated hot water the following morning. Instead we were greeted by water flowing down the drive from the failure of the pressure vessel.

Katie prioritised our installation following the failure of the old unit and our new service arrived from Sydney in a few days. Then Quantum's installer arrived a little later after to connect the new heater.

So well done and thank-you to the Quantum team. Great customer service! We are very pleased with our choice.

It is early days with the unit, and it will be a little while before we receive an electricity account, but I can confirm that the unit is very quiet and below the level we expected.

Paul Cribb

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Questions & Answers

why is the water in the system hot. but not hot coming out not even luke warm
No answers

I hear a loud buzzing every 10-15 minutes. What would cause this?
No answers

Hi, my late father had one of these units put in in 2013. My mum is concerned that the unit seems to be running for longer than usual lately. I've just started taking an interest in it, after a 5 minute shower it seems to run for around 4 hrs. We are in nz and the climate is cooling down after summer, but can anyone tell me what an average run time is? Our unit is a 340-11AC4-134. My elderly mum is concerned the thing will get too hot and burn the place down! Our unit doesn't seem to have the red alert indicator on the outside, so I guess I have to take the cover off the top of the cylinder and see if the control box is showing any error codes. Any advice appreciated, thanks, Jeff
No answers

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