Bosch Hot Water & Heating Electronic Highflow 21e

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

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.

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,

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.

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 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 50...

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 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.?

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.

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 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 a...

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

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 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 t...

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.

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 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 ...

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 .

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 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...

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.