20 Most Recent Bosch PowerStar AE115 Tankless Water Heater... Questions & Answers


Tankless heater are a little frustrating sometimes but this is generally an issue of waterflow I believe. The fluctuations are do probably to the amount of water and rate of water going through the heater. If you have a shut off valve on the cold side of the heater, shut it back about half way. This will slow the water going through the heater and allow the heater to heat it up more efficiently. Then go to the shower, turn the hot on all the way (no cold) and allow it to heat up. Once it has heated up, test it by hand for a good temperature that you like. If it is too hot, turn the cold on just a bit until it comes to the temp you like. If it is too cold turn the hot down just a little (still no cold) and it will warm up. Ideally you should be able to turn the hot on full blast and then just turn on a little cold to get the right temp. Once you learn how these work then it makes it easier. You really cant run the water like you do with conventional hot water systems and expect to get the same results. Also, wanted to give you another little tip. Every 6 mos to a year, you should flush you heater with vinegar for about 30-45 minutes using a small cheap submerible pump like for a water feature in a garde. Just put in a bucket of vinegar and and run a hose to the "in" side of the heater and another from the "out' side of the heater and then back into the bucket. This will circulate the vinegar inside the heater and clean all the deposits that will DOA your heater. Funny how the manufacturer wont tell you this but these deposits will ruin the connectiosn on the heating elements. You can make your heater last for a long time if you do this.

Bosch PowerStar... | Answered on May 31, 2017


9:10 times the control board is bad. You are wise to suspect as much.

Bosch PowerStar... | Answered on Mar 31, 2017


The left canister probably has a grounded element in it, which will keep power going after the water is off. Either that or you have a bad triac on your control unit

Bosch PowerStar... | Answered on Mar 23, 2017


Increase your flow, sounds like you are right at your activation rate.
1 way is to turn down the temp on the machine, so you dont have to mix in so much cold at your shower. Check to see if your mixing valve is bad, or your showerhead has restriction/scale built up in it.The other way is to turn on your lavatory fixture full hot before showering(which will keep hot water flowing through the machine as you adjust your temp to be comfortable.

Bosch PowerStar... | Answered on Nov 01, 2016


make sure you have the water connections right. the inlet goes on the blue side. Also, your pressure must be a minimum of .8 psi. If not there will be no hot water and the neon will be off. other possible causes might be a crossover in your plumbing or a stuck flow transducer. Here is a link to a guide to explain how to check these items. http://efficientelectricwaterheaters.com/Tech-Support/PowerStar-Tech-Support.asp

Bosch PowerStar... | Answered on May 28, 2014


The PowerStar AE115 unit replaces the PS19T model which has been discontinued. Now's the time to upgrade...

Bosch PowerStar... | Answered on May 22, 2014


Light flashing while water is flowing means you have a bad control board. Needs to be replaced. They can be purchased online

Bosch PowerStar... | Answered on May 06, 2014


Can you be a little more specific...?

Bosch PowerStar... | Answered on Feb 15, 2013


Problem might be crossover from failed single-handle faucet cartridge:
http://waterheatertimer.org/Crossover.html

If you need further help, I’m available over the phone at https://www.6ya.com/expert/gene_9f0ef4df2f9897e7

Bosch PowerStar... | Answered on Nov 26, 2012

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