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Rinnai Infinity 20

Rinnai Infinity 20

2.7 from 17 reviews

Not happy with Rinnai B20 unit.

Just recently moved into a new build with a Rinnai B20 50degC unit installed. This is my first experience with continuous flow hot water and I would say that the “B type” builders special units are not as good as a hot water storage unit and I wouldn’t recommend it over a storage type as the hot water temperature can’t be controlled effectively when showering as the minimum flow rate is too high to have a warm shower with a 9L/min shower head as the minimum flow rate on the B20 is 2.4L/min from what I have read which means nearly 1/3rd of the water needs to be hot water which doesn’t work when you just want a warm shower in summer and not a hot shower. This means you effectively have to run the tap as straight hot to “pre-charge” the pipe in between with hot water and then turn it down to the temperature you want for a couple of minutes before the water in the pipe runs out and then swing it back to straight hot again to fill the hot water pipe again. Not my idea of an enjoyable shower.

The standard infinity units are probably better as the minimum flow rate rate on these is only 1.5L/min from what I’ve read but it begs the question as to why weren’t the “B type” builders units fitted with the same flow rate switch as the standard infinity unit or is it just a marketing ploy to keep the standard units sales for end user purchases (where the sale is actually analysed and compared against other heating units) and sell “B type” units to project builders who only care about the price and where the end user usually has minimal to no input into the purchasing decision. If so Rinnai are actually doing themselves a big disservice as people will only associate the brand with being unreliable in any new build home where the builders units are fitted and when those people are looking to input into the decision (and they will in the future if they have had issues with their existing unit) they won’t be looking at Rinnai.

Date PurchasedDec 2018
1 comment

Excellent with one oddity....

Quick to fire up, lots of hot water (58-59 C). The only thing that puzzles me is the odd drop in pressure occasionally as it's firing up. Seems if the internal temperature is below some preset it restricts the flow for a moment until the temperature in the heat exchanger has a certain rise. Once warm (as in washing dishes and such) it really doesn't mess around. I'm pleased. Not excited... as it doesn't have as good a warranty as I had hoped, but the price was fair, the installation quick, and I can basically ignore it and know it's going to work.

Date PurchasedNov 2018
Thank you the review Mitch. Infinity 20 heating to 60 C has a maximum water flow rate of 11.5 litres per minute. When the hot tap is initially opened the heater will allow all of the water to flow, within a second or two the heater will calculate what temperature is required and also adjust the water flow down to match the output. To achieve 60 C in this case there will be a noticeable reduction in flow. If a controller was installed and a temperature of 40 C was required (for showering) the water flow rate is 20 litres/min so there would be very little change observed. Two or more controllers would increase the warranty.Sounds like I'm looking for a kitchen controller and a bathroom controller! Thanks!! (Thumbs UP!!!)

Water is not hot and condensation on the solar panel

I have reported condensation issue on my solar panel and we had Rinnai technician came to fix this issue and they still can't fix this issue and going on with this issue for more than a month now. Why not get it replaced Rinnai? It is a brand new installed and within two weeks we noticed this condensation issue as well as water is not hot. I won't be happy till this solar panel is replaced since you already sent technician more than twice on the roof. Is this quality gone so bad?

Date PurchasedAug 2018


I have an solar hot water system with an Rinnai solar 20 gas booster. I have had issues with it not getting hot enough. I have checked temps in the bathroom and kitchen which are struggling to get to 40deg's. I checked the temp at the closest tape which is in the laundry, it only gets to 45deg's. Is there some way I can increase temperature to 50deg's +??

Date PurchasedAug 2015
1 comment
Thanks for the review Joe.Mc, you should be getting hotter temperatures with your solar hot water. Even if the solar gain isn't hot enough the gas boost should raise the temperature. There is some room to boost the temperature and this should have been completed at the commissioning stage of the installation. It allows for a true 50 degrees at the first bathroom tap. We would recommend asking the installing plumber to return and adjust the unit for you. If they have any issues they can contact our Technical Help Desk while on site to discuss. The number is 1300 555 545.

Luke Warm Water

Had a temp controlled (50 degree) Infinity 20 installed a few weeks ago. Using a pool thermometer the delivered to shower temp seems to be around 38-40 degrees (just tolerable in winter - saving on gas and water tho as not hot enough to hang around). Contacted plumber who advises unit cannot be adjusted and to ring Rinnai. I ring Rinnai technical support, who, after a 40 minute wait in the queue, could not have appeared to be any less interested and suggested I ring the plumber. On current experience stay away from this unit/supplier.

Date PurchasedJun 2018
Thanks for the review LizM. The Infinity unit can be adjusted up to 5 degrees so the temperature at the first bathroom is a true 50 degrees. (there can be temperature loss through pipework from the unit and this adjustment can be made to counteract this). This modification should be completed by the installing plumber as part of the commissioning of the unit, this is not a unit fault. The instructions are supplied inside the unit so this change can be made if required. We would recommend asking the plumber to re-attend and to complete this part of the commissioning and restore a correct temperature delivery for you.Thank you Rinnae - I will do so however the temperature at the first bathroom, not three meters from the unit, is 38-40 not near 50.It will depend on the pipe run to the bathroom, which may not necessarily be direct from the unit. However if this is the first bathroom on the run, the testing of temperature at this outlet should have been completed by the plumber. If the plumber has any issues he can contact our help desk from site on 1300 555 545 option 3.

No hot water at all

We have had the B20 for about 2 years and have nothing but problems with it, having a shower and the hot water cutting out half way through, our plumber could not find a fault so Rinnai came out after insisting we pay a call out fee of $198.00, yes $198.00 CALL OUT FEE, they said it was our shower heads causing the problem but the same thing happens even when trying to fill the kitchen sink just to wash the dishes, piece of crap, ive clicked 1 star because there isn't a no star option

Date PurchasedOct 2016

No hot water at all

After reading other reviews there seems to be a consensus that the B20 has an inherent problem with no hot water at all especially when cold weather sets in. I had the plumber who installed it check it, he said it was ok. I had gas company check gas flow and that was ok. Then today there was no water flow at all again. Not happy wouldn't recommend Rinnai.

Date PurchasedJan 2016
Thanks for the review Saj, we are sorry to hear you are having issues with your hot water service. We would like to look into this further for you if you can send through your details mentioning this review, we will be in touch.No problems, can you send me a contact email as I dont want to post my details on this site. Regards SajHi Saj, our email address is enquiry@rinnai.com.au, please quote 1806-208622 as your reference number

Written Material about the product

I have searched the internet for 2 hours and I can find no reference as to whether or not the Infinity range 16, 20 B26, 26 requires an electrical power point at or near to the position of intended installation of the product. We need to find this information before we purchase the item.

Date PurchasedMay 2017
Thanks for the review She, all the units in the Infinity range require a power point in order to operate. Our website has downloads for each of the products, including Operating and Installation Manuals and Warranty booklets. Alternatively our customer care team can be contacted on 1300 555 545 with any further queries. http://www.rinnai.com.au/hot-water/continuous-flow-hot-water/infinity/20/Thank you. I needed that information. We need to install it where there is no electricity. Your response is really appreciated. She

Worst hot water system I've ever had in my life.

I will never buy or recommend a continuous flow hot water system ever again in my life. It took so long to save for it, and now I have to start saving for a new one. One with a tank that I have always been happy with. I trusted the plumber when he raved on about it, and he called me negative when I said what some of the reviews said. Now I realize those reviews were 100% true. It's a heap of crap!

Date PurchasedNov 2016
We are sorry to hear your disappointment in your new hot water system Tereze and would like to investigate further if there is anything we can do to help. We find most issues are easily resolved if the unit has been installed correctly. We offer a free phone service with our technical team on 1300 555 545. They can explain the best way to use your unit as they can be quite different if you are used to a hot water tank. They can offer troubleshooting over the phone and referral to our service department if a service is required.I absolutely hate my Rinnai Hot water system. I was NOT told it only goes up to 50 degrees. I have to boil water to wash my dishes as the water is barely warm when I fill the sink. And so much water is wasted before the water even warms up. If I had been told this before I was coerced into buying it by the plumber who was just supposed to do a small repair job on my previous system which I loved because the water was at the temperature I wanted it. I am so very disappointed as I was totally misinformed about the product by the greedy plumber who wanted to profit from selling it to me...Thanks for the comment Tereze, the Infinity unit come in different temperature ranges and there is no difference in price between the 50 and 60 degree unit. We would recommend discussing this matter with the installing plumber.

Lovely endless hot water

We recently ugraded from a 20 year old gas tank to the infinity 20, we also upgraded our copper pipework to have this as it needs to be made larger for instant if you previously had storage. It was the best decision ever. It does take 30 seconds to come through at the other end of the house but we can run multiple taps/showers at once and both have hot water without affecting the water pressure. Its so nice to have endless lovely hot water.

Date PurchasedAug 2016
1 comment
Thanks for the review Taryn, it's great to hear you getting the right advice when upgrading from a storage tank and gas supply. We wish you many more years of endless hot water.

B20 temperature is fine if adjusted.

I had a B20 (the builders version) installed early July 2016 and initially had the same problem as other people with the temperature not being hot enough for my liking. The default temp for these units are either 50 or 60C,

The shower is about 5 meters from the unit and was very warm but not hot. The kitchen sink about 10m away was not hot enough for washing greasy dishes, I could hold by hand under the flow.

Having read about temperature dipswitches on certain units, I got my plumber to have a look. He had not heard of them before even after being in the industry for 6 years.

There are temperature dipswitches on the B20, there is a tech sheet in the front panel showing the settings.
He adjusted them to max (there was no specific temperature mentioned in the tech sheet).

Initially he got the settings wrong as the water was hot then would be cold after 5 mins of continuous running.
After a second check, he set them correctly, and the unit continuously pumps out hot water so very happy with it.
Guess I'll find out later whether running the unit at a hotter temperature decreases its lifespan.

Date PurchasedJul 2016
1 comment
Thanks for the review inxs. There are different temperature settings for the continuous flow units. Plumbing regulations require a maximum temperature of 50 degrees at the hot taps used for bathing purposes, the 50 degree units are designed with this application in mind, as they do not require a tempering valve to be installed and can reduce the cost of the installation. These units are adjustable up to 4-5 degree so the installing plumber can make sure they are getting a true 50 degrees at the tap at the nearest bathroom to the unit. Running the unit at the higher temperature will make no difference to the lifespan of the unit as they are designed to manage temperatures much higher.

terrible system -waste of water

recently installed rinnai infinity 20 , unhappy as this unit is wasting so much water , and it doesn't give the temperature we need , water is just warm and this is a new unit , rang rinnai but no satisfaction .regret changing the old rheem it was much better .rinnai infinity 20 rating , I would say 2 out of 10 .

1 comment
Thanks for the review Angela03, the INFINITY unit should be giving you hot water however it will depend on the model chosen. If you have a preset 50 degree unit, you may find this does not feel as hot as your previous unit. We'd be happy to discuss this further with you to ensure you are happy with the hot water and we can be reached at enquiry@rinnai.com.au

No hot water when it rains, the unit is not wet.

We love our Rinnai infinity 20 but it will not work when it rains, the unit is not wet as it sits under the eaves, the rains dries and the unit starts working again?
The unit is under 2 years old and initially worked in all weather.
How can we fix this issue?
Thanks L.

Thanks for the question LTru, there are a number of reasons this could happen. As it only happens when it rains, it would be best to have a service call booked when the problem occurs. In some areas when there is heavy rain it can cause water in the gas lines which would cause the unit to cut out. the plumber can test the gas onsite to see if this is the problem.Thanks Rinnai, turns out it was the Gas Meter and a sump in the street filling with water when it rained, all good, Hot water again, Rinnai was not at fault. L.Thanks for the update LTru and glad to see the issue has been resolved and you have reliable hot water again


No I don't work for Rinnai. In 2014 I replaced my 180ltr gas storage system with the Rinnai B20 unit. After more than 12 months use I can confirm that my gas usage has reduced by at least 70%. So far have had no reliability issues. To get an even temp you must have a controller. Probably takes a wee bit longer to heat up but a small price to pay I believe. Installer did a fantastic job, which probably helps too.
I highly recommend this product.

1 comment
Thanks for the review Deano and the advice about controllers, they really do make a difference to the unit. We are glad the hot water system is serving you well. It's great to hear the installer did a good job too, which eliminates a lot of issues.

No hot water

I have had this Infinnity 20 for about five years, no problems. Now when waiting for water @ 50 deg the readout drops to 12 and no hot water comes through. Please help . The first unit lasted about 12 years without a problem. Could the fault be with the unit or the touch pad . John g

Thanks for your review John. It should like your unit is faulting with an error code 12 which usually relates to a lack of gas to the unit. Is it possible there has been an interruption to your gas supply? We do have a technical help desk that might be able to trouble shoot with you and can let you know if you need to book a service call for the unit. Their number is 1300 555 545 and they are open from 8.00am to 5.30pm Monday to Friday.Thank you for your prompt response. I will check with the help desk. Cheers, John g

Rinnai infinity 20

Rinnai infinity 20 had put in a few weeks ago great product will never go back to another brand .Just one thing if the electitiy goes off do you have to close the gas line or do you just leave it .It does take a few minutes before the water gets hot but it should work that way

1 comment
Thank you for the review Netti, it's always great to hear when our customers are happy with our units. With regards to your question about when the electricity going off, as a safety feature the unit will automatically turn off the gas into the unit so you do not need to manually turn off the gas.

Can't understand what everyone is complaining about!

Although I've only had the Rinnai Infinity (20) for a few months, it works as advertised. The time to get hot water to the taps is similar to the previous storage hot water system the Rinnai has replaced (from about 5 seconds in the bathroom to perhaps 10 or 12 seconds in the kitchen). I've had no problems whatsoever at relatively low flow rates (WELS approved shower heads etc are no problem), and water temperature is constant. I do use the water controllers, which make shower and bath time so easy (no need to juggle hot and cold taps). The max I use in the shower is 42 degrees (according to the water controller), so even for someone who likes the shower REALLY hot it wouldn't be a problem. I note that although the unit is limited to 50 degrees, there are dip switches inside the unit that allow the temperature to be increased slightly, to compensate for losses in the pipework (i.e. it's designed so that you can achieve 50 degrees at the tap, not just 50 degrees at the water heater).
Hot water is truly continuous. The water controllers are perfect for bath/shower use.
Some documentation suggests that the Kitchen controller may be increased to 55 degrees, however it seems the model I have is limited to 50 degrees max, no matter what.

I'm a plumber , if your waiting a while for hot water after you turn on the hot tap it's because of the distance between the unit and were the tap is u turned on, and if your complaining about the maximum 50 degrees , try to stand under the shower at that temp bet your not there for long before you burn!Hi Doug. I only posted the time taken to get hot water as many people were complaining about it taking a long time with the infinity continuous heaters. My point was that it's not significantly longer than with the previous storage hot water heater I had - so yes, it's just a factor of the pipe distance. Regarding 50 degrees, of course I wouldn't like to shower with water that hot, but for kitchen and laundry use there are times I would like an extra 5 or 10 degrees.

See all Rinnai Infinity Range reviews

Questions & Answers

I've lost hot water. Everything working fine. Gas, power, water. Just no hot water. We had a power outage and since powers been back on the hot water hasn't worked.
2 answers
It doesn't have a digital screen or anything. Just the box.Thank you for the question Dally Sam R. Please contact our 1st care customer service on 1300 555 545 option 2 for further assistance. Thanks, Rinnai Australia.

Our Infinity 20 is 17 years old and works perfectly. But recently it has started making small explosive (popping) noises. They occur when the unit is not being used . Any idea what's causing that?
3 answers
Thank you for the question John N. Please contact our Technical help desk on 1300 555 545 option 3 for further assistance. Thanks, Rinnai Australiajohn it is a great water heater, but like every thing else when it is getting old it may need a check up, a visit buy a rinnai teck. prob. would be a good idea. mechanic.Thanks. Yes tech has been. Seems it could be leaking.

Got no hot water when turn tap on. With tap on turn water isolating valve off then on, boiler clicks and works again. What could be the problem?
1 answer
Thank you for your question Eric M. In order for Rinnai to assist you further with your enquiry, please contact our free Technical help desk on 1300 555 545 option 3.


Infinity 20
Price (RRP)1395
Release dateAug 2007
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