250SX Bosch Tankless Natural Gas

Old 03-21-08, 05:28 AM
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250SX Bosch Tankless Natural Gas


I have read a lot of the prior posts on Tankless Hot Water heaters, the good and bad encounters.

Back about 2003 I bought an electric tankless for my home in Dallas Texas and never had a problem it filled my 90 gallon Jacuzzi easily. It was very expensive ($3000.00 for the electrician to install).

Now to today. Two and half years ago I bought here in Arkansas a Bosch 250SX Natural Gas Tankless.

There's lots to this thread, but our main disappointment is the kitchen sink and I saw that reported in previous emails and yesterday I got the final word from Bosch that "That's just the way Tankless work". My mom does not have a dish washer so she does dishes the way most people, she turns the hot water on to rinse some, then turns it off as she washes more, then on to rinse and so on.

The problem is, even after turning off the hot water for 5-10 seconds, it will be hot for as long as that 122 degree water is in the pipe but then it usually either turns warm for 30 or so seconds or it may even turn cold for that time. Bosch's suggestion yesterday, keep the hot water on the entire time but he said turn it halfway or only on enough to have the GPM for it to stay hot. So much for saving resources, anyway my mother is disgusted with this. The other option he gave and think is mentioned on this site by another poster, install a 4 gallon tank under the sink to solve having permanent hot at the kitchen when turning on and off.

The above is only the tip of the iceberg. I'd estimate since we've had this I, my mom and her boyfriend have about 15 hours or probably more troubleshooting this not working right, max waiting for Bosch 2.5 hours on hold average waiting 30-45 minutes before reaching someone--they always say "Well there's bad weather on the east coast". I will say Krista from Bosch over the last 3-4 weeks troubleshooting was very good and helpful, so not all bad.

Cost? I have about $4100.00 into this tankless investment to date. Unit was $1100.00 cost of plumber to install initially $1100.00 so there's $2200.00. About 2 1/2 months ago the unit quit heating it would not turn on, turns out the rain came down and flooded the gas valve. Bosch sent us one for free overnight. $230.00 plumber cost but original plumbing company paid for it because they installed it according to plumber 2 company in the valley of the roof the gas vent that is and felt that was it. We were without hot water for 7 days until the plumber got to it.

Then a month later same problem. This time the Bosch tech said we should have been told by Bosch that we needed a Bosch T Drain pipe retrofit so any water coming thru the top hat of the vent would drain down, hit the T which then would carry any excess water into the condensate drain. Cost--$600.00 for parts overnighted $200.00 in two separate overnight deliveries. Plumber cost to install--$930.00. And with a few other miscellaneous cost around $4000.00. Oh yeah this second time without hot water 13 days, we didn't seem to be a priority to the plumbing company I suppose.

But the flooded gas valve should be fixed for good now.

In all this, we've had the gas pressure measured: 9.3 at the meter, 9.2 at the tankless with just tankless running, 8.3-8.5 at tankless with all gas running, stove, oven, tankless, Central Heat so that's well above 5 which Bosch says must be at least 5. Bosch sent us new temperature sensors, that didn't do it. They sent us a new retrofit temperature overheat sensor as well, neither of these fixed it.

The tankless is above the 2 foot fit pantry and into the attic. The copper pipes are not more than 22 feet run in the attic down the wall to the sink, not a far distance. Cannot turn hot water off without it most of the time going lukewarm then cold even if off for only 5-20 seconds.

I did ask the Bosch supervisor yesterday "You mean this is desiged to work the way it does, how does a person wash dishes without it getting cold" and he said he leaves his running half way until he's done with dishes.

One other thing I've learned for anyone else, the GPM Gallons per Minute is important and ours is fine, 1 GPM at the kitchen sink in 50 seconds, about the .8 per minute required by Bosch. Shortly after buying it, the single scald proof faucet in the bathroom we had the water would not get hot enough. Turns out had about 1 GPM, he had me take the shower head off and remove the plastic restrictor and I bored the tiny hole about twice as big allowing more water and that solved the shower issue.

This has been in the end a very expensive mistake I made, but I had wanted to 1) save pantry space and 2) do a little to reduce natural gas use.

Look forward to comments.
Old 03-21-08, 12:16 PM
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Hi Perry. Welcome to the forums. I'm sure sorry to hear how much trouble you're having with your mother's tankless hot water heater.

I think the amount of money you paid is outrageous and I can't imagine how installation would be so high, but gas installation is not a field I'm familiar with.

What I can tell you is I have an electric. I paid $700.00 for it over the internet. The brand is Seisco. I had it installed by a plumber and an electrician. They worked together, because neither of them had installed one before. It took them about three hours and they charged $500.00 total. Both men were licensed, but not bonded and insured. (Couldn't find anyone willing to install who WAS bonded and insured!)

If you found one of my earlier posts, you already know, but it's worth repeating...

The Seisco quit working one week shy of the 2 year warranty. I tried everywhere to find someone to service, finally found a company who said they knew how to work on them. Called the Seisco company, asked for repair parts. (The company rep talked to the repairman who already was showing evidence of not knowing what he was doing.)

Seisco said they'd send the parts, but I had to pay for shipping, which was dear because they would overnight it.
The next day, a whole new, upgraded unit was delivered-not just the parts.

The repairman didn't return. (probably just as well) My husband,and I, plus a neighbor, followed the installation instructions and installed it ourselves. None of us are licensed plumbers or electricians.

It does take some getting used to, and perhaps some people will never be satisfied with a tankless, but I wouldn't trade mine for anything. If it broke again tomorrow, I'd go right back and get another.

Old 03-22-08, 07:14 AM
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Connie, sorry to hear about the trouble you had. I have to say that anyplace I know about, if you are not BONDED, then you are not LICENSED. A license requires a bond. And if they are not insured, then they are just moonlighting, and likely did not pull the REQUIRED PERMITS for this work, putting you and your homeowners insurance in jeopardy.

Tankless water heaters normally need extensive gas supply and flue work, for the gas models, and extenive electrical work for the electric models. Installing one for $500, well, that probably explains why you had issues.

Don't mean to throw a damper on all this, but the whole point is that tankless heaters are much more complicated than "plain old waterheaters", as evidenced by all the issues both of you have pointed out.

All the manufacturers recommend that their units be installed only by installers who have received training from the factory reps in the area
Old 03-22-08, 08:39 AM
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Hi 594 tough,

Thanks for your comments. I hope I didn't sound like I was complaining-that's surely not my intention.

The problem is FINDING someone who is authorized to install and service these tankless. I called 7 companies who specialized in water heaters, none of them did tankless. And the one company who said they COULD service, sent a guy who knew nothing. (Only one of the four channels wasn't heating...he cut the unit from the pipes to start.) So, even when someone says they know what they're doing, perhaps they just think they know.

It's a great technology, but hasn't the infrastructure to support it. I think the HVAC people need to get on board and learn how to service and install, before folks like Perry become disillusioned and give up on the whole idea.

If you read some of the back posts, you'll find other complaints similar to Perry's. I realize my replacement unit will have no warranty, since we installed it ourselves...nothing I can do about it.

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