Questions and Answers for Bosch 4 Gal. Mini-Tank Electric Water Heater (3-Pack)

A:  Manny, The model ES4 maintains hot water as long as you have the unit turned on. If you have the unit turned off for an extended period, you will want to winterize it. Instructions for winterizing are in the manual that is linked to in the product description on this web site.

A:  It keeps the water hot but use it as an on demand heater. We have an light switch conveniently located under our sink. When we need hot water to wash dishes we flip it on. It takes about 10 minutes to heat up the tank.

A:  This is a tank type not on demand or point of use. You can always switch it off during the winter. I have mine installed in my outdoor kitchen.

A:  I believe it has a 4 gal tank that keeps the water hot. Works great in my shop.

A:  It keeps the tank hot all the time that it's plugged in. It's fairly efficient but for that application I would you could build an insulated box to put it in to help keep it from losing too much heat from being exposed. I guess technically you should see if there's any minimum spacing requirements in owners/installation manual but the ventless design should be very safe even enclosed. Hope this helps!

A:  Manny, this is a 4 gallon water storage hot water tank- it heats up water and holds it at a set temperature. After you use about 4 gallons it takes about 30 minutes to heat the water back to your set temperature. So it comes on periodically to keep the water at the set temperature. You can unplug it if you are not going to use it for a long period of time. If temps are below freezing you would have to take precautions to keep if from freezing. It is NOT an "on demand" water heater only turning on when water is running.

A:  I am not sure parts would be available for a low cost item like this unit.

A:  Doug47- I have never replaced the anode- when heater stops working I replace the heater. I believe the 4 gal model anode part number is 574305. I could not find this part on Home Depot web site- but if you put the part number into you web browser- you will see other folks sell them for a reasonable price. One of the large on line retailers has many reviews on replacing the anode- which folks say is pretty easy to do- there are also some good photos included. .

A:  It is not simple to replace the rod and heating element which are often covered in calcification after a few years; depending on your water quality . Plus you have $80 in parts. Almost easier to just replace the whole thing.

A:  Did not replace the anode ,as a result it start leaking after 3.5 years,which is not covered by warranty. Should not be difficult to replace it, but heather need to be drained and heating element needs to be removed as well.

A:  We have never had a problem

A:  It’s relatively easy if you have good access to the front of the unit.

A:  omg... YES replace the anode annually. Hardest part is draining the water. Use a shop-vac to suck the water out the cold side after turning water & electricity off. Use common sense. Open the relief valve or faucet when sucking the water out. U-Tube

A:  Carlos, "Technically" yes. However, "practically" there are limitations that may suggest doing something different. Many customers find that they can get an adequate shower with this ES4 unit. This will be a much quicker shower than one may be accustom with a standard size tank. Plus, if the sink is also pulling from the tank at the same time, then the duration of the hot water shower will be reduced even further. You may want to look at stepping up to our model ES8 which has a 7.2 gal. reservoir vs. the ES4 at 4 gal. Another option for you is to consider using one of our tankless electric solutions that have no reservoir and never run out of water. For your application our model US12 will certainly work and our model US9-2R is an option if you are in a relatively warm climate (such that your ground water temperature is warmer tan say in Maine). The tankless electrics do require direct wiring and will have greater electrical needs in regards to the circuit's amperage and wiring. All that are mentioned here are available on this website.

A:  Probably not. Your hot water lines for your sink and shower likely split before any available place to insert this connection. Your shower hot water line is (probably) contained in the wall. If you have a basement beneath this bathroom, you may be able to install this before the hot water line splits. Even then, 4 gallons of hot water is not a very long shower.

A:  I have seen no change in electric bill for the past month since installation.

A:  Depends on use, temperstures, and cost of power. It seems to heat water in about 1/2 hour at 1440 watts. At 13 cents per Kilowatt hour that's about 10 cents per full use. Then it has to remain hot, so there is an ongoing heat loss to ambient that will demand additional power even when not in use. The amount of that loss would increase with the unit thermostat setting.

A:  Abe, There are too many variables here for us to answer this correctly. The number of times used, how much water is used each time, your ground water temperature, and the ambient temperature around the unit are all factors.

A:  Not 100% sure. I have it on a 30 amp breaker.

A:  That probably depends on your water quality. If you get sediment or have very hard water it would probably be smart to install a filter or water softener to protect the hot water heater (and all other appliances and valves in your house). Hope this helps!

A:  We have a well and have had no problems at all.

A:  pkb, if you have clean water from a pressurized system-when you turn on a spigot water runs out- then this will work. As with any electric hot water heater the quality of the water could effect the life of the heater.

A:  No mind is on a well system with no noticeable issues

A:  No problem here

A:  Entirely depends on how the piping runs from the outlet of this tank. If those pipes also feed the other sinks' hot water connections then yes, it will deliver heated water to them. If it is only connected to one sink then no, it will not "back feed" other sinks in the system.

A:  No, it will only provide hot water to the sink it is connected to. It should not backflow in to the main hot water line which is pressurized.

A:  JP5050, This will work as long as the model ES4 is installed such that your Hot lines to all these mentioned locations are fed from the ES4. Also, the assumption is that this is being used as a booster and not as the only source of hot water for these locations.

A:  I imagine it could provide hot water to other faucets, but it would depend on the connections. If the outflow is connected to one sink, it will supply hot water only to that sink. You would need to connect it to the hot water supply line leading to the other faucets, showers, etc.

A:  In a typical installation the answer would be no. In a typical installation you would mount the heater under a sink- connect the hot water supply line to the heater and install a new supply line from the heater to the hot water spigot. Only that sink would get hot water from the heater. If you wanted the heater to temper the water for all three hot water sources in you bathroom you would need to find the supply line feeding the bathroom and cut into it and install the heater. This could be difficult depending on how your water lines are installed. Personally I would not attempt to do it in my home.

A:  See my product review Feb 18 2021.

A:  The water heater is not designed to work outside exposed to the elements. It is designed to be installed in a dry location. If you mean outside in a shed or garage that is okay. If you mean outside exposed to the weather the answer is no. You also need a proper electrical outlet near the water heater.

A:  Not sure if it can be installed outside. I have installed two under two kitchen sinks and so far no signs of rust.

A:  No, the electrical connections aren't in a rain-proof enclosure.

A:  No. I would not recommend installing this outside unless it is covered on top and all sides from rain.

A:  I wouldn't suggest installing it upside down. If you use fittings that are easily unscrewed from the input and output it would not be that hard to unplug, disconnect and pour out the water.

A:  Camperdude, The model ES4 should not be installed upside down. The installation/operation manual is available through a link on the product page. In the manual there are three different methods listed for draining the unit.

A:  In my opinion all lines should be blown out with a compressor set at no more than 45 psi, doing that and opening up your taps one at a time will get rid of all water in pipes and heaters, you could also use rv water anti freeze

A:  No, it can't be installed upside down, its supports are meant to hold it upright.

A:  The instruction manual does not show an upside-down installation diagram. Suggest you call Bosh and ask an 'application engineer' the question! Bosh Technology Corp. 866.642.3158 boshheatingandcooling.com. Good Luck!

A:  Camperdude I would not install the unit upside down- it is not designed to work that way- with the placement of thermostat and heating element, or bracket to mount it. I suggest you make final connections to your plumbing system with flexible sink supply lines. So when you leave- you unplug the heater from the electrical outlet, undo the two lines with a turn of a wrench and remove the heater, turn upside down and empty the heater and store it for your return visit. It would take less than 5 minutes to remove and drain and you could reinstall just as quickly.

A:  Tommy, specifications says it uses 12 amps. It plugs into a normal household outlet. It would draw about the same amps as an electrilc space heater or a large hand held hair dryer.

A:  I am not sure exactly, but I'm running it off a 15amp circuit, so less than 15Amps probably less than 10Amps! I would ask Bosch if you think you don't have enough Amperage going to the outlet.

A:  12 amps at 120 volts

A:  15 amps if it is the only item on the circuit. I have mine on a 20 amp circuit, along with a dishwasher.

A:  It draws under 12 amps so can be plugged into a 15 amp circuit.

A:  You can hook up the old water lines to the new heater yourself. If your old hot water heater has a connection for the Emergency Release valve (I call it the pop-off valve) that is vented to the outside of your home, you can also hook this up yourself. If it doesn't, you will have to have a plumber install a line.

A:  I suggest you call your local store and ask their customer service people. Most stores work with contractors that do this type of work.