Review by D. Vance:

We bought this water heater for our guest house. After major rewiring and plumbing changes and drywall repair from the rewiring and plumbing, we were finally ready to install. The installation went well and at first it seemed the system was working. However, after a short period of time, the water was not staying hot. It fluctuated in temperature when taking a shower and trying to do dishes in the kitchen sink, it actually went cold. We thought something was wrong so we called CPO (where we bought it) to see about getting this unit replaced, and they referred us to Bosch. After troubleshooting with Bosch on the phone, changing settings, water flow, etc., over a period of a few hours, we were not getting the improvement we had hoped for. To get hot water, the water pressure had to be turned so low that you could not reasonably expect to take a bath…it took forever to fill the tub. We continued to try different settings for a couple of days, but we had guests coming and needed hot water (which we had tried to explain to Bosch) so we went to the big orange store and bought an identical unit for 9. That one worked much better and proved to us that something was wrong with the first unit. Trying to return the unit to CPO, they required an incident number from Bosch. Called Bosch to get an incident number (why didn’t we get one in the first place?) and had to call back several times due to long waits on the phone. They will not give an incident number unless they determine the unit is defective. If the board needs to be replaced, they will replace that, but will not give us an incident number to return the unit. So now we have a paper weight that cost 0. CPO will take it back, but not without charging a restocking fee and shipping. Why would we want them to restock this and sell it to someone else? Our only recourse at this time is to get back on the phone with Bosch and try to have them determine whether or not this item is defective. Never mind that they would have us go without hot water the whole time. This has been frustrating and expensive. Also, even though we have one that works, it is not really robust enough for a whole house water heater. Better as a point of service heater, but then you better make sure you have a big enough electrical service in your house to manage everything else you need to use. We have 200 amps, but if we needed two of these units, we’d have to upgrade our service in order to accommodate the huge amount of power these things need up front. Don’t buy one of these unless they get the technology more stable.

Review by Ernesto Perez:

Great product. Will give you enough hot water even for the new england cold weather area.

You will need to fine tune the water flows and consider the anti-scalding faucets to reduce cold water intake, because you might get too much cold water flow. Once you balance the flow you will get a very nice hot shower!!

something worth to install.

Review by DoItYourSelfer:

EDIT – 1/11/08 ————————————————-

I’ve been having trouble with the Aquastar lately. It still works but doesn’t like to work when the furnance is running. I assumed the furnance was drawing down the gas pressure in the line but after having the gas company out and an HVAC technician they both concluded the pressure is steady and sufficient. Contacting Bosch technical support has proven to be an exercize in patience to say the least. Each phone call (there have been 3) has taken a minimum of 50 minutes on hold. I’ve spoken to three different techs and have been given three different solutions. First call, very nice lady, apolgized for the wait, I told her the problems and she sent me a new control box (didn’t work). The second time I called, the tech told me it was my problem and not the Aquastar. He said I had insufficient gas pressure (I didn’t), said I had a vent back draft (tested, I didn’t) basically he blew me off. He gave me the phone number of a local tech (wasn’t local-40 miles away) that I’d have to pay for (because it was my problem) to come and diagnose my Aquastar. I decided to call back because I was very unhappy with the technical support I had just received. My intent was to make a complaint, but on my third call I talked to yet another tech who diagnosed yet another possibility. He sent me another part to replace, which still hasn’t solved the problem. Which is where I’m at at the moment.

I’ve done some more research on the internet and it seems that Bosch Hotwater tech support is reknown for poor service. Unfortunately that’s something you only find out when the unit isn’t working.

I’ll have to change my recommendation from a buy to a don’t buy at this point based solely on customer service. Hot water is not something you can readily do without for any period of time and if you do have a problem with the Aquastar, waiting days to have it fixed is not a solution.

Another curious observation, why is there such a wait for tech support? Must be a lot of broken Aquastars out there.

END EDIT ————————————————

I installed the Aquastar 1600H myself in about 3 hours. I bought it at Lowes and like the other reviewer, had to go to HomeDepot to buy the 5″ class B ducting. I gave the Lowes sales ppl an ear full about that but it just went in one ear and out the other.

If you’re comfortable with sweeting copper and plumbing your own gas lines its really not that difficult. My biggest problem was positioning the unit so I could vent the exhaust gases. If you don’t have a straight vent stack and have to feed the exhaust into the chimney like I did, it required placing the unit really low on the wall. You are required to vent straight up for the first 12″ before you can elbow the vent. Along with the minimum run vs. rise of the vent pipe, it forced me to place the unit just barely a foot off the ground. Your situation may be different but keep it in mind. Also, it requires a minimum of 3/4″ inside diameter black iron gas pipe. In some cases if you’re tapping into the same gas line as your furnance, you may have to install 1″ gas line. This unit requires a lot of BTU’s and if you choke down below 3/4″ it will not run properly. So that means no yellow flexible line to make the last connection. You’ll have to hard plumb the iron pipe all the way to the unit.

There are both benifits and negatives to this unit. First the benifits. Long, long, long showers. Literally, you can take a shower all day. Then the next person in line doesn’t have to wait for the water to heat back up. It’s ready to go. Great for a family getting ready in the morning. Second, big savings on the gas bill. My bill dropped the month after I installed this unit. I figure it will pay for itself in less than two years after the tax credit.

Now for the negatives. Low hot water pressure. That takes some getting used to. The unit has a maximum 4.3 gpm, but that’s really unreasonable.(Take into consideration that I’m in the Northern USA and the water in coming into the house is at 50 degrees.) At that flow rate the water doesn’t heat up above 90 degrees. That makes it warm not hot. You have to turn down the flow rate to 2.3 gpm to heat the water to 120 degrees. At that flow rate / pressure, if you open two hot water spigots anywhere in the house at the same time it becomes a trickle. There is no way you could run the shower or any other appliance like the dishwasher or washing machine at the same time. If you turn the Aquastar back up to 4.3 gpm you could, but you’ll be taking a warm shower not hot (in my case).

Also, at 2.3 gpm, it takes a long time for the hot water to actually get to the faucet. It probably takes 4 to 5 times longer than it used to for hot water to flow from the tap than it did with the old tank system. For example, if I’m washing my hands, by the time I’m done lathering up and rinsing, the water is just now starting to get hot. I’ve come to realize its not even worth turning the hot water on for short burst of hot water like that.

It takes adaptation to get use to this, like this trick I use in the morning. I turn the hot water on and brush my teeth while the water is slowly making it’s way to the tap. Once it’s hot, then I turn on the shower. Otherwise I have to let the shower flow for what seems like a very long time before it starts getting up to temperature.

Would I recommend this unit. It depends. If you really need the ability to run two showers or two appliances at the same time, then no way. You’ll have to go with the next unit up that has a faster flow rate. There’s no way this unit can handle that.

But if you think you can adapt to the low flow rate and really enjoy taking all day hot showers while saving money on your gas bill then this is the unit for you. I really enjoy the savings and long showers.

One more thing. The manual says you have to clean the unit once a year to maintain its efficiency. That means disassembling some parts in the unit. Clean them and put it back together. I haven’t had to do this yet, but its just one more thing to consider before you switch to tankless hot water.

Review by Macs R We:

I installed a Bosch 1600H-NG in a small (900 SF) home a little over a year ago. Installation wasn’t tough, and hot water flow was adequate for a small home in our warm climate.

I bought this unit because its piezo ignition feature would guarantee us hot water even if power to the home went out. There were battery-driven units, but I figured if you had a choice between having to change batteries regularly or not, why sign up? Trouble is, the turbine in the ignitor is insanely sensitive to small particles of grit and rust, which jam it and shut down the heater. I have had to disassemble and clean this turbine three times in the past year (twice in the past three weeks) which is a messy job (the plumbing attachments on the bottom of the unit ensure that all spilled water is generously dispersed over the floor). This is despite my having put a whole-house grit filter on the water feed after the first instance. Right now, changing batteries looks a lot more attractive. I wouldn’t buy this unit again.

Update, 9/09: After the first problem with grit and the installation of the whole-house grit filter, it appears that the subsequent problems were caused by the improper reinstallation of the turbine rotor. The instructions are completely unclear on this step, and it’s possible to install the rotor reversed and have it work, at least for a little while. Once I installed the rotor in the proper direction, I have had no more issues with this heater. I’d like to upgrade my review to four stars, but it appears that it’s no longer editable. The basic point stands: don’t install this heater without a grit filter on your water system.