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Thermann Gas Continuous Flow 6 Star

Thermann Gas Continuous Flow 6 Star

3.2 from 15 reviews

Very happy with this unit

One month in since I installed the Thermann 6* 16L and I'm very pleased. I only need to wait around 15-20sec to have a very hot water in the shower (@60C), I don't experience any water temp' fluctuation, and the water flow is steady.
the only reason I gave it 4*and not 5* is because you can't change the temperature without buying the R/C for an extra $100.(which I didn't buy)
Please note, the system is for serving two people with minimal use( showers and a bit in the kitchen ), the distance from the unit to the shower is around 8 meter, and to the kitchen is around 4 meter.
The installation was straightforward and cost $1100 including the unit.

Date PurchasedNov 2018

Absolutely crap.

Constant waste of water. From every outlet I have to wait ages for any hint of hot water with the cold turned off. The temperature also fluctuates still with the cold off. Sometimes it doesn’t even kick in and send hot water, I’ve had to go and turn the unit off and on again. Another waste of my money thanks to a plumber highly recommending it. Very very disappointed

Date PurchasedApr 2015

Agree wholeheartedly with Worst Item Ever

So much water is wasted to actually get hot water. Bought this thinking it would be more economical, stupid decision. Used to be able to have a 5 minute shower, now to get 5 minutes of water at a perfect temperature I am standing there for at least 25 minutes. Shower goes cold after about 3 minutes. No good just trying to adjust the hot water tap. Have to completely turn the shower off and start again - so again you're wasting litres of water to get hot water. Our gas bill is also now a lot more!

Date PurchasedFeb 2018

Thermann 6* 20L C/Flow 50DEG NG

Very pleased with the Thermann 6* 20L C/Flow 50DEG NG unit. The installation is for a small cottage with 1 bathroom. All kitchen , laundry and bathroom outlets within 14 feet of the heater. The install took about 5 hours and included the removal of the DUX electrical off-peak tank and changes to plumbing pipes in that area. I am new to the 50C hot water regulation, but the water seems hot enough to wash dishes in and the shower is comfortable to bath in and flow seems fine. I did have the water saver shower rose removed and a standard rose fitted to the shower, it is an 8 litre per minute WELS shower head. The all up cost was $2192.20 which included $220 for a level 2 electrician to remove the off peak meter from the meter box and $126.50 for the electrician to install the outside power point and terminate, in a block ,the off peak power line.

Date PurchasedAug 2018

Only want a good shower

I thought that it wasn't very good for the first two years, terribly bad pressure in the shower, good every where else, I had taken out shower head restrictor didn't seem to make any difference,, finally found another restrictor at the inlet, goodness two of them, my shower is now perfect

Date PurchasedMay 2016

Worst item ever

So much water is wasted to actually get hot water. Bought this thinking it would be more economical, stupid decision. Used to be able to have a 5 minute shower, now to get 5 minutes of water at a perfect temperature I am standing there for at least 25 minutes. Shower goes cold after about 3 minutes. No good just trying to adjust the hot water tap. Have to completely turn the shower off and start again - so again you're wasting litres of water to get hot water. Had an elderly relative stay who needs a shower chair, she had to bathe at the neighbours - she would either have 3rd degree burns or be frozen at our house. Continuous hot water - what's that?????

Date PurchasedJul 2017

Installed new Thernann 26 today. Less than impressed.

I just had a Thermann 26L/m continuous natural gas hot water unit installed today. My water pressure at the mains is 75psi before installation and I don't have any water saving heads in the home. So no problem with water pressure. When the plumber left and I got a chance to use it, I noticed it takes a good 30-45 seconds to go from cold water to luke warm and then rises to 50 degrees after a minute. My hand basin is on level ground less than 5m away. My kitchen about 10-12m away was worse. I turned the hot water on and had to wait over a minute before it got anything hotter than just luke warm. You would fill a kitchen sink full with wasted cold water before you get any hot water out. This is a complete waste of water.
The worst thing, is after you visit the toilet and go to your hand basin to wash your hands. You're washing in cold water for 10 seconds even before the unit has any sign of mildly heating up and then you stop the water. Say goodbye to washing hands in warm water on a cold winters day. This is a 1 bathroom house. I live alone. This has been a disappointing $3000 investment all up installed and connected to replace a 250L electric tank HWS including an updated circuit in my electrical powerbox.
I will not recommend this product at all. Over a minute to get mid to high 40's and then 50 degrees is abysmal. This product came 'highly recommended' by the Plumbing and Electrical Doctor. 'Everybody gets these units now and they are great' I was told. I actually read up and found the 26 sizing too excessive for my use and requested a 16 or 20, but again was told 'We recommend and only install 26's in every house now'. For such a highly praised company to highly praise this unit, one would expect a level of performance.
This morning I had a shower. The water took over a minute to get to temp. In the early stages of the shower it went warm and then luke warm, then warm again to hot. I maybe had to adjust it 3 times at first. But after it was running it had no problem supplying hot water.
The trade off with these units is wasted time and a lot of wasted water. Im in suburbia, but if you are on a rural property and have tank water, Do not buy this unit.

Date PurchasedMay 2018
1 comment
Winter update. End July 2018. I hate this water system! Soooooo much water is wasted passing through it. Now that its winter and ground pipe water temps from the street are very cold, expect to turn the tap on and wait for over a minute to get any warm water through. Go and time 90 seconds of water flow in your shower and see how much water is wasted! The kitchen sinks fill up with cold water before they even get luke warm. This product is a joke. Do not buy this product if saving water or living off tank water is important to you. That wasted water adds up. I dread going to the toilet and washing my hands in freezing cold water afterwards. Be smart. Look at another product.

Better than Rinnai

Just had a Thurmann 26 installed to replace our 10-year-old Rinnai. Heat exchanger in the Rinnai sprung a leak and it was not economical to replace and Rinnai one we're not interested even though it was just over 10 years old and out of warranty and 2. it was going to take them a week at least to get a servicemen to look at it. We had our Thurmman from All blocks Plumbing replaced within 2 days. The Thurmman has a great warranty and the best bit is you don't need to call the company to get their service agent out to look at it, the plumber who installed it is the service agent. My only little gripe is, it does seem to have an audible beep coming from the unit and I cannot find any information on it whatsoever...so Thurmman if ya listening...what is it? (ps no remotes connected)

Date PurchasedMay 2018

Excellent product.

We had one of these installed about six months ago. The hot water temperature is perfect. The plumber recommended this system and it has been a great choice. Would highly recommend one of these continuous hot water systems. It is much cheaper to run than the old electric hot water service.

Date PurchasedSep 2017

Research required prior to product selection

I made an impulsive decision to replace a 25 year old electric storage hot water system with new Thermann gas continuous flow hot water unit. Didn’t bother to research the options and relied entirely on my Plumber whose advice I normally value.
A major downfall with the Thermann unit is one which, from other product reviews, I should have realised prior to its purchase. Whilst the Thermann unit adequately provides continuous hot water for use in kitchen and laundary, it cannot be relied upon to supply continuous hot water to a shower without turning cold for no apparent reason.
With regard to a cost comparison between electric vs gas, in theory gas should be more economical but due the heating process causing huge delay in delivery of hot water to the tap/showerhead there is probably no substantial cost difference.

Date PurchasedAug 2017

Very Unhappy

The Thermann 26 requires a a large volume of water to make it work so it won't work with water saving shower heads which is quite unbelievable in this day & age. It is not possible to close the hot water tap much to reduce flow & temperature as the gas cuts out, as it does if you turn the cold up much. As it is heating a large volume of water all the time to what I consider too high a temperature then it must by definition be using a lot of gas which is borne out by the fact that we now have VERY large gas bills and in a home with only two people and with very little gas used for anything else. Upon investigation with the distributor it seems that the temperature is not adjustable despite the instructions stating that it can be changed by resetting the dip switches. The instructions fib it seems. It is the worst piece of equipment I have purchased for a long time.

Date PurchasedAug 2015


So our we replaced our old gas water heater, Tank type. This Thermann produces a lot of hot water, fantastic. Problem is you cannot use water saving shower heads, need the waterflow to be high in order to get consistent water temperature. The worst part for us, is the exhaust gasses (Carbon monoxide) will fill the shed and or gazebo so you have to vacate these areas until the gasses disappate. So now I have been informed that my options are to relocate the hot water water system (and plumbing) or get a an additional flume to discharge the gasses above the roof line of the house which will hopefully prevent the gasses filling the gazebo or shed.

Date PurchasedSep 2017

What a difference

With electricity prices going through the roof, I recently made the decision to dump electricity in favour of gas. Being rural, I had to increase the size of the line from my LPG tanks to carry the larger gas flow so that the two showers in my home could be used at the same time. The install was made quickly and the over large electric storage tank was removed (so much more space now). I am more than happy with the results and the continuous hot water never runs out (unless the LPG tank does).
I have waited several months to write this review so that I could receive a new electricity bill using just the gas system. I can now say that even with the increased gas usage (and consequent charges), I am making a fair saving over the excessive electrical system I used to have.
If you are thinking of moving away from electricity, this is a good option.

Date PurchasedAug 2016

Thermann Gas Continuous Flow Hot Water.

I had this unit installed to replace the useless Chromagen Solar Hot water system. The Thermann unit I had installed by Diamond Valley Plumbing is the 26L 6 star unit which is preset at 60deg. The water heats very quickly and is continuous without any disruption. The unit comes with a 12 year warranty for peace of mind also. Leaves the old Chromegan system for dead and no stupid oversize storage tank taking up space.

Date PurchasedDec 2016

Thermann hot water system gas continuous flow 6 star

This is the worst system in the world. If only there was an option to give it zero.
I got a plumber to install the system about 4 months ago and has not worked properly from day one.
3 mins in to a shower the system will stop making hot water and I will have to wait another 3 months until it heats up. Rang up the company who advised me that my gas meter was too small and needed to be upgraded. The meter was upgraded, cost me $500 and still the same problem. I know this was a lie, because my sister has a rinnai with a small meter and not one issue. Thermann charged me for a service call out, which of course said that there was no issue. Its been 4 months and still no constant hot water. So much for a 12 year warranty, I have advised everyone I know not to use this system and i advise you all to stay away from this inferior product from Reece plumbing.

See all Thermann Gas Continuous Flow reviews

Questions & Answers

I'm doing a new build and I'm thinking of looking at installing a Thermann C7. Who does their warranty service work if I buy it through Reece. I have heard that if there is a problem with them that they replace them but not service them onsite. Is this true?
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