Bosch Hot Water & Heating Electronic Highflow 21e

Switch off – Why does my hot water switch off? Always goes to cold especially while I'm in the middle of a shower. Its been doing this for the past year. Have had the unit for more than 10 years

Bosch21e – We have 5 of these at our accommodation business along with other brands Cannot recommend them highly enough. Never had a problem with them and they are easily adjustable for temperature control. have 2 bosch professional on as well, and after a few hiccups they are also performing very well. Show details

Wasted my money – The unit was installed new at our weekend place. We had lovely hot water for 4 or 5 weekends. Now it starts then stops straight away. I have tried to find info on how to fix it or through troubleshooting to no avail. Well out of town, would cost a fortune to get a plumber out, so will have to de mount and bring in. They turned out to be very expensive showers. A product that new should not fail, Show details

Stops working in windy and wet conditions – The unit stops working when you need it most, in cold, windy and wet weather. I used the reset button inside the unit to restart it but now it seems to be dead. I am not going to call Bosch as it's seems like a waste of money. Better install a different unit from a more reliable brand. Show details

Never Missed a Beat – The old storage gas hot water system in the roof cavity failed after 30 years (Beasley) but it was installed during major additions and to replace it would mean removing part of the roof or ceiling. So we had a Bosch 21e installed outside. It has been 3 years and it has been reliable with no problems at all. I installed a BOSCH MAIN CONTROLLER… Read more

YPRM67XBN (about $100) not long after the heater was installed and it was the best thing I ever did. We rarely need to use cold water because the controller can be set to any temperature between 37 and 50ºC. My wife and I prefer different temperatures so we just adjust the controller before taking a shower. In winter I use a setting of 40ºC and in summer I use the lowest setting of 37ºC. My only criticism is the temperature settings at the lowest level is inaccurate. 37ºC is below body temperature so it should feel cool. But on hot days it's sometimes too warm for me and I add cold water. Have recently bought a Bathroom Controller YPRS67XBN which will replace the main controller in the bathroom. The Main Controller will be moved to the kitchen. I note many complaints about the Bosch 21e and can only say use a good plumber. Our plumber made sure there was sufficient gas pressure and no leaks between the meter and the house.

The Bosch 21e gives us a much better shower than the previous roof storage heater, and the gas bill has not changed noticeably.

Excellent hws – This hws has been totally reliable and great at supplying us piping hot water over the past several years. It has never even been serviced oops. I am wanting to be able to adjust the water temp now though as our new dishwasher needs a lower temp for ingoing water (there is only a connection to a hot water pipe). I am unable to open the 4 screws… Read more

on the unit.. done up so tight, none will budge. As I need to call a plumber out to adjust temp anyway, I was wondering if a controller can be added to the unit and will it give me the full range of temps ie 50 to 75 degrees? How much do the controllers cost approx.?

Rob, Adelaide – We have had a Bosch HWS in WA and it worked well. You have commented that the 21e unit would not work on cold/wet/windy mornings. Would you mind saying HOW you fixed your Bosch 21e. We have a new 26e and it takes ages for the hot water to be delivered a short distance of 2 metres. Many thanks.  Show details

OMG - This is living!!! – You don't know you have lived until you purchase a hot water system with remote temperature controller units. Firstly the house we bought back in 2015 had a 10L/pm unit in, can't remember the brand but they are common as muck and the hot water trickles out. Going from 10L/pm to 21 was like a dam busting open full of hot water. We bought… Read more

our unit 2nd hand from a demolition recovery yard for $200 and it has worked flawlessly in the 18months we have owned it.

I went out and bought 2 remote temp control pads and fitted to the bathroom and kitchen @ around $70ea off ebay. There is nothing better being able to step into the bathroom and turn up or down the temp based on how you are feeling and then just turn the hot water tap on and the water is streaming out everytime at the temp you selected.

It also makes it very safe for kids in the bath coz you don't have to mess around wondering if the bath is too hot or cold for them.

Another function is bath fill where you can set how many litres dispenses before it cuts off automatically, good for those feeding time hectic times of night when you are multi-tasking you can turn the tap on and walk away.

The only CON with this and I suppose all new units are they a factory preset to MAX temp of 50oc to prevent scalding which is good, but when it comes to cottons in the washing machine you need 60oc + and 50oc is too cool for the laundry and melting grease off pans in the kitchen.

not a right answer – as I said my 21e problem was, when I opened cold water the system turned on, finally I found the right answer, because I did bathroom renovation there was some air on the pipe and the air pressure on the new pipes caused the system turned on even when I opened the cold water tap. solution: easy, open the new taps connected to the new pipes and let the air leave pipes, and then every thing back to normal. Thanks  Show details

Design flaws that product support don't know how to fix – I can reinforce comments by at least one other poster on here where their unit failed to fire on cold/wet/windy morning - basically when you need it most. This started happening to me almost without fail just out of warranty. I first used one of the recommended service providers on the Bosch website who adjusted some levels on the unit, and by… Read more

that time it was probably dry enough to work anyways. Next cold morning it fails again, so I call him back, but he doesn't know what else to do. So I call Bosch who then say its better to call one of their warranty repairers rather than a service provider detailed on their own website. They end up doing a minor fix. Which again doesn't work the next cold day. Call them up again and they change the gas valve thinking that is the problem. By now i've spent basically as much on repairs as the unit originally cost. Although it came into Spring/Summer then, so I figured it was fixed. Come Winter next year it wasn't.

I had my suspicions Bosch had literally no clue how to fix it, and ended up going to Bunnings spending $5 and fixing it myself. ($2.50 of that was for a sausage sizzle). Kind of wish i'd done that in the first place as it would have saved me a ton of cash. And for two winters my fix has been rock solid. Touch wood.

Not overly impressed – Have always had temperature fluctuations. Just renovated the bathrooms and found a lot better. Unfortunately the plumber then made us install a pressure reducer at the main tap. Flow restrictors have been removed from the tapware and still shocking. Now worse than ever. Fortunately we don't live in a cold climate.  Show details

Complete Rubbish. Do not buy one – Hi, We have had nothing but trouble from this E21 hot water service in the whole time we have had it & has cost us a fortune in plumbers in the 10 years also. Our son who has just left home to move into his own home & has bought a RHEEM and has not had to buy a controller as we did which made no difference to our BOSCH & he is happy as Larry. Do… Read more

not buy one. kerr5y

June 13th 2017 Update: Hot water

We are very pleased to see the end of our 21e Bosch hot. Water system it was a rusty heap of junk. The system was illegally installed by the bosh installer and it was however nice to see the back of it. If you don't want a rotten shower then don't buy a bosch they really are the worst..

June 14th 2017 Update: Hot water

We had the Bosch for about 7 years and in that time, it was nothing but trouble nothing but cost us money. I would not be able to recommend a bosch to anybody. It finished up going rusty. On the inside and then would not work we now have a Rheem and we are very very happy.

June 28th 2017 Update: 1 star

This is most unreliable gas hot water heater you can ever buy it nothing but trouble.

It was a real heap of junk rusty old rubbish definitely do not buy 1 unless you want to waste your money. The rheem is absolutely amazing and works wonderfully. And I highly recommend the rheem for great hot water.

Money magnet – Bosch high flow 21e has cost me more money in repairs in the last ten years on parts and labour and now I find out it just cost me another $148 just to tell me I need a new one I know were I would like to stick bosch .

A disappointing product in this modern age – Have had nothing but problems with this Bosch HWS 21e since it has been installed in the rental property. As the property is managed, the ongoing plumbing fees to "reset" the unit is begininng to hurt. the numerous tenants have all had issues with this Bosch 21e unit. The plumbers go to site - i believe to reset the unit. by reset i mean just… Read more

turn the power off then on. A solenoid can be heard to be engaged, which i believe what it is....otherwise keep cyclying power till this "engagement" can be heard. (As i have experienced this problem too while taking a shower,....no hot water in winter is rather disappointing)

Today the property managers have engaged the plumbers to visit and fix the hot water problem as raised by the tennants again. Bill is nearly $200. Recomendation by plumbers is to replace the unit. It is only new as it was installed in 2013 by a major Gas supplier....

Rather disappointing product in this day and age.

never again – 21e installed at the insistence of AGL in 2013 (we wanted a gas storage unit). Have never really liked it. Especially don't like it since it fails on a regular basis since December. Today alone it has failed 3 times. Reset and it goes ok for a while before the same problem happens again. Waste of money, pile of junk. Would never buy Bosch again.

Unreliable: temperature of water - stick to a storage system if you can! – Was persuaded by Gas Works to update our old storage water service after it began leaking (over 10 years old) to this Bosch continuous flow hot water service. Gas Works were very efficient in arranging a new installation, which meant we were only without hot water for one day. However, it soon became apparent that the system only kicked in when… Read more

you had the tap flat out. There appears to be no way to have a gentle flow of hot water. Having a shower became interesting when it completely cut out in the middle of the shower. Gas Works suggested changing the shower head, which we did, and that particular problem seemed to be rectified - but now the temperature of the water is not constant no matter which tap is turned on. Having the temperature limited to 55C is frustrating as well :( I wish I had read some of these reviews before changing our hot water service, I would have stuck with the storage system.

Unreliable it wet, windy or both (weather) – Worked well for a bit over 2 years. Then for no apparent reason it wouldn't produce hot water when it was windy or raining or a combination of both. Bosch approved technician came and had a look and said moisture had entered the unit and not much could be done. (Paid him cash and no receipt). So I started closing air holes off - this seemed to fix… Read more

the problem for about 6 months until this last lot of inclement weather in Sydney. The holes I closed off are still closed and when I listen to the unit the fan starts up when the water is switched on and it the unit tries to fire (I can hear repeated click sound - maybe a dozen - as if the unit was trying to ignite) and the fan noise can be heard for about a minute before it switches off. The fan speed is not constant, sometimes louder then softer then louder. Gas meter indicates that gas did flow into the unit during this time. Anyone have a solution? Yes replace it.

The unit is position along a wall in the weather.

E21 and water pressure – Our unit is now 9 years old and for quite some time it turns off and on during showering particularly when the cold tap is adjusted. A repairer told me over the phone that we should install a new unit for approx $1400.00. No other taps had this problem such as kitchen, bath, vanity or laundry. I have removed the water saver device from the shower head and have had perfect showers ever since. Water flow can now be adjusted to perfection.  Show 4 replies

Re. Set nightmare – Was good until changing gas bottles wont reset,no hot water for two days tried power on off.tried turning water off &gas then back on as advised by Bosch to no avail.Bosch why is this so hard.?next step a plumber-will cost money-for something that should be easy to rectify.looking at emails this is a recurring problem.

How does I reset the water heater? – Just wondering if anyone can tell me how to reset the water heater? On my bosch21e system. We have only been in our house for 4 months and ran out of gas. I have a full gas bottle attached so switched system over and opened gas however still no hot water. I read the bosch 21e manual online and it says that the water heater will need to be reset.… Read more ·  1

But didn't tell me how to reset it. So I turnt off the main power and switched on again. That seemed to do the trick and we now have hot water. But I'm wondering if there a reset switch on this system somewhere? As I don't want to have to switch off the main every time we run out of gas. Thank you in advance :)

cutting out and temp fluctuations – We installed a bosch 21 e 10 ish years ago. After a few years on very cold mornings it would turn it self off with in 1 minute of starting,so you would have to reset it by turning it off and on at the power point. The water would also not stay consistent, you would have to be adjusting continuously. To solve these problems I fitted a bathroom controller and it seemed to fix both problems! Now we only need to turn the hot water tap on.  Show 2 replies

Disappointed – I have a 2 yr old Bosch 21E hot water unit which has recently developed a fault. It intermittently fails to produce hot water usually at night. I was charged $126 for a service technician to reset it after which it worked for 1 day then failed again. I have now reset the unit myself several times after which hot water is produced for a short (1/2… Read more

to 1 day) time. The unit occasionally restores itself but never for very long. This problem is occurring with increased in frequency. Very disappointing.

2 Seperate 21e's in 2 townhouses have both BLOWN theBOARD after only 7 years – I am a builder and fitted 21e units to 2 townhouses on the same block 7 years ago and both let NO WATER out of the HOT WATER taps. Turn off and on at power fixed them for a short time, but now doing it nearly all the time. Had service tech look at them and told need new BOARDS at $500 EACH SHOULD LAST LONGER THAN 7 YEARS!!!! JUNK

Hubba! Hubba! Hubba! – Everything! Looks good, performs well, and has saved me a fortune on electricity. If I could sleep with it I would but my wife gets so jealous that I am afraid to take the chance. My best friend is renting and he has been trying to persuade his landlord to put one in but so far, he is behaving like so many other landlords do. It might have been a… Read more ·  3

mistake to tell him about my wonderful heater as the relationship with his landlord is deteriorating fast, which is sad, because he fancies the landlords wife. Price, Performance, Economy.

Hopeless in power blackouts – 21e - hopeless having this unit if you rely on electricity as well - when you have a power blackout you don't get hot water - even though it is a gas unit. Bought this house 18 months ago, unit is not too old and the i am going to replace this with an instantaneous gas unit. No hot water in power blackout.

Bosch 21e – Hi, we are temporarily renting and there is a Bosch 21e unit installed, not sure how old. The problem we have is that when it rains we have no hot water. Not sure if it is the moisture in the air that causes this. We can hear the spark trying to ignite, there is smell of gas but no hot water. The only thing we're sure of is that when it rains we have cold showers.

Bosh hi flow 21e – Not happy far from it we brought a new g j gardner home two years ago and this system was already in place we are disappointed with this unit. Every time we want hot water we have to run the tap flat out for approximately up to a minute before the warm to very mild hot water comes out which is not suitable for washing dishes so we have learnt… Read more

to live with this and we boil the water when we want to wash the dishes.

I cannot believe we have not complained about this until now.

Bosch highflow 21E – We had this system installed 8 months ago, have used 4 cylinders of gas since (2 people live in the house) the water temperature is scalding, so you have to turn the tap down to colder, when you do all you get is cold water so you turn the hot on again only to be scalded. Each time the gas goes off and we change to another cyclinder you… Read more

cannot get the hot water to start again. Contacted the Rinnai tech support by mistake, they were so helpful, but then we found out it was not their system but if it had they would have helped us to fix the problem and also told us what the problem was with the system not re-starting after the gas is gone.

It was an easy fix, so we then phoned Bosch tech support, what a waste of time. basically get your plumber out to fix it, more ??? on top of our expensive gas bill and change over and get your cylinders to switch automatically.

Then you have no idea when you need to get a cylinder replaced and are likely to always need gas when they are shut and cannot deliver or pay a premium to get gas delivered over a week-end or public holiday.

Overall not impressed with this system at all. Have never had Rinnai system but based on the reponse and helpfulness of the tech support would definately recommend them.

Scalding water, very bad customer service, expensive to run

Not a good product – My Bosch Highflow e21 is dangerous, the unit turns itself on when I haven't even turned a tap, there is gas smell coming from the unit even when its not running, the last cylinder only lasted a month,and we are a two person household only using gas for the hot water. would not recommend this product

Terrible – Bought a house with 21E version in and I cannot wait to get rid of the silly thing. Very hard to keep the shower warm, it is either 50C or freezing cold. Am unable to use the water to wash the dishes in as, it is just not hot enough. Hot water is limited to 50C. Would not reccomend to anyone. System runs quiet Water goes from hot to cold. No… Read more

other taps in the house were touched and it still goes cold after a minute. Water only at 50C so useless for washing dishes in. No hot water if power goes out.

Excellent – What is wrong with the rest of you? This machine (21E) works great!!! We love it! Temp only fluctuates if another tap is turned on. We would not hesitate to buy another one! Make sure you have it installed properly by a professional, then you'll have no probs, like us! Delivers constant hot water always. Great when you have people staying, & you… Read more

never run out of hot water. Takes a while for the hot water to hit our kitchen sink (furtherest point from the heater), so a lot of water is wasted. Fluctuates in temp only when another tap is turned on.

Bad – My 21e is an $800+ enviromental disaster It has to use too much water and therefore more gas. This is totally against the principles of an instantaneous hot water. I can't find any reference to this min. flow rate in instructions, only a false statement that if run below 2.5 L/min. the temp. could be unstable (on page 15) It will be unstable… Read more

according to Bosch, when you ring them, below 9L/min. This is true. At first it appeas to save on energy use, but all models must have a water flow rate of more than 9 lit/min. in the shower-much too high for drought areas. Unless you shower is a fire hose the temperature control is a joke. This is a serious safety factor. It saves gas because the water is often dead cold.