Customer Reviews

Bosch 125B-NG AquaStar Natural Gas Tankless Water Heater

5 star:		(11)
4 star:		(2)
3 star:		(3)
2 star:		(4)
1 star:		(3)

 

 

Well, looks like my prior review on 4/22 has been deleted. I highly suspect that the complainers here, or one of them, "reported" me because I referred to their reviews and that probably violated policy, yada yada yada.

Ain't it the way of the world? Wonder how long this one will last.

In any event, if you are at all interested in the AquaStar, just listen to the positive reviewers, hook it up properly, and you'll be very happy with it I'm sure.

I suspect that the most common problems folks have are twofold:

1) They probably don't use the required 3/4" gas supply pipe and try to get by with the old 1/2" pipe that supplied their old tank-type hot water heater. Most 30-40 gallon tank types have a BTU input specification of 40,000 BTU's. The 1/2" supply line is adequate for that number of BTU's, but the AquaStar requires 117,000 BTU's and that's three (3) times as much. Thus you DO need to use the 3/4" supply line or you're just not feeding the thing enough fuel.

Don't give it enough gas to burn and what do you think is going to happen?

2) A lot of folks might try to get by with the old 3" vent pipe their old heater used. Again, that's not going to work. You NEED to vent the AquaStar with the proper-sized vent pipe or it's not going to breathe properly and thus not going to work properly.

Other than that, there's not much to worry about with the installation of this unit.

Install it properly and it will perform well for you and meet your expectations fully for many, many years to come.

Also, as I noted in my amended review previously -- now deleted of course -- this model here has changed from when I bought mine a few years ago. This new 125B has a standing pilot. If you want one like my old 125B, you now need to get the Model 125HX, which has the electronic ignition, as does mine. The difference between mine and that one is that mine uses 2 D-cell batteries, whereas the 125HX uses a water-powered turbine to supply the necessary electical power to fire the unit. Neato.

Also note (as I mentioned previously) that the former manufacturer, CONTROLLED ENERGY CORP., has been acquired and thus is no longer the current manufacturer. Try going to their former website and see for yourself.

I doubt this has compromised the quality or service, but it's something you should know.

After reading several reviews on the Aquastar, I was coinvinced to write a review after reading W. Youngs' review. From personal use of the water heater in my own home and installing seveal higher priced competitors models in customers homes, I am happy that I installed the Aquastar for myself. First of all, the Aquastar cost at least half of most other models. Second, it does not require any electrical supply saving one less thing to do during installation. Third, Mr. or Mrs. Young must not have done a correct installation because these water heaters definitly work. They may have accidently crossed a cold water line with the hot line allowing cold water to enter through the hot water side of the faucet. Or, maybe they didnt have the right size gas supply to the unit. Overall, this unit performes with the best. I recently moved and already have installed one in my guest house and plan to install one in the main house during upcoming construction. There's nothing like a hot shower after a long, dirty day on the job site.

I have installed two of these units and have found them to be excellent water heaters. They are easy to set up, the pilot (if you have one that uses a pilot) lights easily, and they instantly deliver water so hot you will need to adjust it with the cold water tap to not scald yourself. Also, they never run out of hot water and you will save money on your utility bill because, unlike a typical (boiler) water heater the water does not need to be maintained at a constant high temperature whether or not you are currently using it. The water is only heated at the time of demand.

I just finished my review on the 250SX-NG model before the New Year's Eve and I like to comment on another reviewer's review, W. Young's in particular. I agree with David Wood, these tankless water heaters do work wonderfully if installed correctly. I had an old 40-gallon water heater (almost 20 years old) died on me on New Year's Eve (read the story from my review on the 250SX-NG), so I had to replace it. I picked up a Bosch 250SX-NG from a local store along with the venting kit made for that model, 4 hours later I was in hot shower on the second floor (the Bosch is in the basement). It does take 30-40 seconds for the hot water to get up on the second floor, but when it does, it will get scalding hot if turned up. I just don't see how cold water goes in, hot water comes out can be messed up. Some people mentioned that it takes thousands of dollars to have it installed. Natural gas tankless water heaters have been very popular for many years in Asian countries. I just don't see how that would be possible if the installation cost is that high. And I don't see why Bosch requires extreme expensive installation either.
Cold water between uses is expected with tankless water heater. It's just the way it is unless you want your house be like a hotel or you can have a in-line hot water buffer tank that is heated all the time.

Our Aquastar 125B NG is older, manufactured prior to the Bosch purchase of the name, and though everything looks the same I do not know what design changes Bosch has made. It was already installed in our house when we bought it, so I have no information about the savings relative to a traditional tank water heater. However, I can offer some information about general use of this unit.

It is true that you can only fill demand for one hot water activity at a time. If the dishwasher kicks on while you are in the shower, both of them go cold. Your dishes will have spots and you will be shivering in the shower. Another reviewer suggested buying the unit with larger capacity (greater GPM) than what is recommended for your square footage, and perhaps this is a good idea.

I've found that in the winter time my Aquastar is extremely sensitive to variations in water flow unless I crank the gas knob all the way to the right on the front of the unit. This means it's basically "off" or "on", i.e., luke warm or scalding hot. During the summer I tune the knob back just a bit without issues, but if I leave it that way, I find that my water heater will randomly shut off or have trouble maintaining a constant temperature during the winter. It was irritating before I figured this out, as showers would suddenly go cold and the only solution was to turn off the water and turn it back on, which is no fun when it's already a little chilly in the house in the morning.

I do not fully understand this issue, but it seemed to me that the combination of cold pipes and changes in water flow played tricks on the flow switch and caused the heater flame to shut off. While this problem was occurring, I also noticed that the pilot light would go out frequently, which is also irritating. I downloaded the manual and went through the troubleshooting, which described this problem exactly, and the suggested solution was to turn the gas flow knob up. This didn't occur to me before because I had it just a tiny bit backed off from the maximum - I assumed any more adjustment would not offer any significant performance changes.

With the knob all the way to the right, hot water is nice and hot. Really fricking hot. Also, in the shower the slightest change in the knob leads to huge swings in water temperature. So it's a little too sensitive at this setting, but I'd rather have a hot shower. Despite this lack of adjustability, it is very nice to have an indefinitely long hot shower.

I also learned that it is expected that one perform periodic maintenance such as replacing pieces related to water flow. Perhaps mine is due for a replacement and may be causing my issues with inconsistencies related to temperature and flow. Nonetheless, while the water heater is functional and I have all the hot water I want, it appears that the technology is not yet seamless and transparent, and I'd prefer a bit more refinement. Again, my model is older and perhaps improvements have been made since it was manufactured. Also, my attitude may change after I perform a few maintenence items. But so far this requires more attention than any traditional tank heater I have seen.

I have used a tankless water heater before in my last home and really liked the ease of installation . The money saved from using this type of water heater can't be ignored either. I would recommend this product to anyone installing a new water heater as I have already done with friends. The extra expense on purchase will be recovered in a smaller gas bill in the long run.

Just installed my 2nd unit in an apartment owned by my family and both are performing awesome. Unit arrived in a timely fashion and is relatively easy to install has plenty of energy transfer for operating a single fixture at a time. Would have given 5 stars but controls, although completely functional, are a bit cheap.

I bought 2 of these units from Home Depot. One has been working pretty well for about 5 years. In the winter the wife has to use the other side of the house for baths as bath flow allows water to go through too quickly to be heated adequately. There is supposed to be a flow valve to control this but I think it failed a year ago. Other than that the unit is still working fine and works well for showers. The other unit has been miserable. It keeps sticking in the On position and auto shuts off when it over heats. I have replaced the parts to supposedly fix this with no luck. The only solution was to replace the entire lower unit which costs about $125.00. This fix only lasted 6 months. The new unit was the new plastic one that is supposed to be smoother than the original Brass one and should last longer. It didn't, I only got 6 months out of it. I just rebuilt it this evening and it didn't improve anything.

The biggest problem is you can't find a plumber anywhere to repair these things. You may be lucky enough to find one to install them but repairing them costs as much as buying a brand new unit. No one ever talks about these issues. They are great when they are running and completely spank when they don't. I love the concept but hate the faulty technology. Upon reading the Bosch site they state they may need to be rebuilt every 6 months in areas with hard water. Consumers need to know this prior to purchase. Regular tank water heaters may build up sediment but don't have to be rebuilt every 6 months.

Technical specifications from the company are at [..]
It lists the gallons/minute expected at various degrees you have to heat your water--for example, you can expect about 2.5 gal/min of hot water if you have to increase water temperature from 50 deg. to 130 deg., which is about the highest an antiscald faucet will let you go. If your incoming water is colder than 50 deg., you will get less hot water flow. The 4.3 gallons/minute quoted in Amazon's description is listed only for a 45 degree increase in the water, which would require your incoming water to already be at 85 degrees if you want 130 degree water out. I don't think water coming out of the ground into the house is not going to be this warm. The site also discusses minimum gas line size, something another reviewer mentioned as important. Also important is your total water pressure and what water flow you typically get. I live in a rural area and can get only about 2.5 gal/min of water period due to my low water pressure. So, 2.5 gallons of hot water/min doesn't sound bad to me, as that's all I get anyway!

Bear in mind that the %savings often quoted are the savings on the energy used to heat your hot water, not total % off you monthly energy bill.

I find it useful before any major purchase to consult a manufacturer's site for technical specifications.

Update: Check not only your total amps into the house, but amps other stuff draws--in my case the heat pump and water heater together would push total amps to the limit and would need new (bigger) breaker box installed. I found this out only when I talked to an electrician; my total amps in met the stated requirements, and if I had a furnace instead of heat pump, might be OK.

I'm an American and so help me God I want a shower that will peal the skin off my back and scald me at the same time. Ok, that's a little over the top, but still, I like a good shower and this water heater is decidedly wimpy.

The good features: Installation was a snap since it uses common off-the-shelf class "B" vent and it does work. Also, it can produce enough hot water to take a weak shower and it hasn't froze up in subzero weather.

On the negative side: There's no automatic damper, which means you have a gaping 5" hole open to the winter sky, letting in a draft of ice cold air. Second, it produces pretty weak "hot water," even on the highest settings (admittedly the incoming water is not much above freezing). Along with that, doing laundry takes F O R E V E R. The hot water flow is so sluggish the washer waits an eternity to fill.

Finally after 3 months of pathetic showers, I ordered a second tankless water heater to serve as a booster. Now with 117,000 BTU's of gas backed up by 15,000 watts of electricity. . . all is well with the world. :-)

In summary: "there's no substitute for fire power" and it takes a lot of energy to heat water on demand.