Bosch - Tankless Waterheater ???????

[Lunker]

So I lost hot water and went to check on the 4 yr old Bosch Tankless water heater what could be the problem.

I come to find out that that the heater is running full speed ahead, so I go back upstairs and try the hot water again...nothing! So I go check another faucet figuring it was something wrong at this location... No hot water. I go back down stars and the tank-less water heater is still running, and it is getting hot and smelly down in the basement, the pipes are starting to bang/knock...

I touch the water outline from the heater and it is ice cold...the supply line on the other hand is boiling hot.

I turn off the gas figuring this can't be good...

Water is now starting to drip below the heater...

I take off the cover and the heat exchanger is black and several wires are starting to melt...

What the heck happened? Anyone got any insight into this and Bosch tank-less heaters in general...

I figured it would be a good investment, but 4 yrs later it seems I completely wasted my money having this installed...

[TheOak]

What is the warranty like?

I just purchased a Rinnai tankless unit. I've got 12 years on the heat exchanger, 5 years on parts, 1 year on labor. Assuming a similar warranty, you would obviously have to pay for labor, but the rest should be covered.

Your home owners insurance might even flip the bill once you have paid your deductible too depending on what type of coverage you have.

If things are melting, I would definitely turn off the electricity, natural gas, and water to the unit and get someone in to look at it. I would start by going to Bosch's tankless website and calling in someone they recommend. This would insure that the people looking at it have expertise in this type of water heater.

Good luck ...

Edit:

When you say "no hot water" and "nothing" does that mean there is water coming out, but it is cold, or you are getting no water at all?

Does the Bosch have an inbound water filter? Perhaps it got plugged, end result is your unit was not getting any water. Have you "flushed" the unit lately for build up? Hind site is 20/20 ...

Either way, I say get an expert in ...

[hj]

Your description is completely puzzling. The burner is running wide open, you have water flowing from the hot water faucet, and it is cold? On the surface that seems to be an impossible scenario, since if water is flowing through the heater and the burner is on there should be NO way for the water not to be hot. The burned wires and the black heat exchanger may be relevent to the problem, but again, on the surface, they appear to be a different problem.

[Lunker]

I removed the water-heater and will take it apart and see if I can find out what what happened...

This was a 125 Model with no electric hook-up, just natural gas and water.

I'm figuring I must have had two failures at the same time.... maybe it clogged and stopped the water flow..AND the burner switch failed at the same time...

Weird stuff...

I went out a bought a different brand, we'll see if that works better...

Tried calling Bosch customer service Friday night... they are available 9-5 M-F of course.... :(

[Lunker]

Your description is completely puzzling. The burner is running wide open, you have water flowing from the hot water faucet, and it is cold? On the surface that seems to be an impossible scenario, since if water is flowing through the heater and the burner is on there should be NO way for the water not to be hot. The burned wires and the black heat exchanger may be relevent to the problem, but again, on the surface, they appear to be a different problem.

Sorry if it was confusing, the hot water stopped flowing from the bathroom faucet upstairs. I initially figured it was just that faucet because when I went to check the heater it was running. At that point I did not touch the pipe to see if the water coming out was hot... 20/20 I should have of course.

[TheOak]

I am curious, what brand and model did you purchase? Did you stick with tankless?

[Lunker]

Rheem-Ruud. Hopefully it will last more than 4 yrs.... :)




I am curious, what brand and model did you purchase? Did you stick with tankless?

[TheOak]

I have heard that the Rheem's are relabeled Paloma's which have a pretty good rep out there. You should at a minimum get a better warranty ... ;)

[Gary Swart]

Help me do the math. You have a tankless water heater that I assume you paid considerably more for that a standard water heater. It lasted 4 years and will either cost a great deal to repair or even more to replace. Here's where my math skills are weak. I can not figure out how a tankless water heater saves money over a conventional heater.:confused:

[TheOak]

See this thread (http://www.terrylove.com/forums/showthread.php?t=23477).

If it is all about money, then you are probably looking at a 10 year payback minimum. With that being said, I have heard of installation costs coming down a little. Perhaps costs are coming down ... perhaps it is a sign of the times too.

If you ignore the installation costs however ... the main reasons a tankless saves over a tank are:

1. There is no pilot light that is always on as with a tank.
2. It is not heating water when you are not using it. A tank will use fuel to keep the water warm during the night, when you are not using it for example. With a tankless, it only heats water when you turn on the hot water tap.

Remember though, there are other forms of "payback". For me, a HUGE payback is the endless hot water. My family can have shower after shower after shower after shower (concurrently too) and then do a few loads of laundry and then the dishwasher ... I still have hot water coming out of my ears ... ;)

[Lunker]

No need for math-skills with this equation. In my situation it didn't, and it wasn't really the reason why I got it, I was just tired of running out of hot water. On the other hand, I was sort of expecting to last 15+ yrs as a added bonus. I though Bosch was a decent brand, needless to say I'm pretty disappointed.



Help me do the math. You have a tankless water heater that I assume you paid considerably more for that a standard water heater. It lasted 4 years and will either cost a great deal to repair or even more to replace. Here's where my math skills are weak. I can not figure out how a tankless water heater saves money over a conventional heater.:confused:

[Gary Swart]

I have a 50 gallon power vent Richmond (Rheem) 50 gallon heater. This has an electronic igniter so there is no pilot light. It is true the heater will operate anytime the water temperature drops in order to keep the water ready for use. The unit is 12 years old and I have had to replace the ignition control module twice in that time. The last time about 2 months ago. The module costs just over $100 and is an easy DIY job. I also had to replace the dip tube a couple of years ago at a cost of about $10. A new Rheem power vent runs $600-$700, which although is about twice the price of a conventional vented heater, but that is far, far less than a tankless. We never have run out of hot water even if we happen to run the dishwasher, shower, and clothes washer at the same time.

My point is, I am not at all convinced that when the costs of installation, including gas or electric service upgrade, unit purchase cost, unit installation cost, repair costs, and life span will be off set by the higher cost of operation of a conventional heater. I believe tankless is a great idea that just hasn't been developed to the point of being truly economical. I also believe that it probably is just a matter of time until technology solves the problems and makes tankless worthwhile.

[hj]

The pilot light is almost insignificant as far as gas usage is concerned. Unless you have a very poorly insulated water heater, it will NOT turn on during the night. In fact if no water is used it might not turn on for a day or so. But if you are running the heater continually for hot water, you are not saving money.

[Lunker]

I'm just happy the house is still standing. If this had happened when I was not home, who knows what would have happened.

Scary stuff....

[TheOak]

Totally ... I have not heard a lot of good things about the Bosch units ...

It could be though that because they are sold at the DIY stores, more people have them and hence you hear more people complain about them.

Whenever I "surf" the general impression I get from posters is to stay with the "big guys"; that is, Rinnai, Tagaki, Paloma. The reason I went with Rinnai is that I heard they kept their temperature better from a few posts. The rest were a bit more expensive too ...

[Ladiesman271]

So I lost hot water and went to check on the 4 yr old Bosch Tankless water heater what could be the problem.

I come to find out that that the heater is running full speed ahead, so I go back upstairs and try the hot water again...nothing! So I go check another faucet figuring it was something wrong at this location... No hot water. I go back down stars and the tank-less water heater is still running, and it is getting hot and smelly down in the basement, the pipes are starting to bang/knock...

I touch the water outline from the heater and it is ice cold...the supply line on the other hand is boiling hot.

I turn off the gas figuring this can't be good...

Water is now starting to drip below the heater...

I take off the cover and the heat exchanger is black and several wires are starting to melt...

What the heck happened? Anyone got any insight into this and Bosch tank-less heaters in general...

I figured it would be a good investment, but 4 yrs later it seems I completely wasted my money having this installed...



Sounds like you skipped the scheduled maintenance that is required for most any tankless unit.

What is the model number of your old unit?

[Ladiesman271]

If the model is a 125FX, read the last page for the maintenance schedule. Water filter need to be cleaned every year. Water valve needs to lubricated year 2, and needs a rebuild in year 3 to 5. Warranty is invalid if you skip that routine maintenance.

Sounds like the water valve is stuck on. Not sure why water is not flowing, but it is related to the water filter and / or the water valve.

Maintenance parts are pretty cheap. I keep a spare water valve, valve rebuild kit and lube in my plumbing kit!


http://www.boschhotwater.com/Portals/7/TechManuals/125FX_English_12_yr.pdf


Better check out the routine maintenance requirements on your new unit!

[Ladiesman271]

We never have run out of hot water even if we happen to run the dishwasher, shower, and clothes washer at the same time.




Just wondering how many people have needed to do that even one time in their lives.

My clothes washer is set for cold / cold operation, so the water heater is barely used for washing clothes.

I don't know anyone who ever runs the dishwasher while they are taking a shower.

Now some families may "need" to take two showers at the same time. That would probably be a killer for my tankless, but that is easy to work around!

[Gary Swart]

I did not mean to imply that there would be any time that hot water would be used that way, I wanted to point out that a good 50 gallon water heater will supply continuous hot water for as long as you could possibly want to be using it even if it was for multiple uses. I'm sure that larger families might use more hot water at any one given time that we do, but for a normal household, it just isn't a problem.:)

[jadnashua]

A good tank WH can have as little as 1/4-degree per hour loss in temp. Standby losses are an issue with a tank one, but will never come anywhere near the extra cost to install and maintain a tankless. If your incoming water temp doesn't vary (you live in a mild climate) a lot or you are certain you'd never need to use multiple fixtures at the same time, and you will do the required maintenance, they may serve you well for awhile. It will cost you more. Thinking you'll save the difference in standby losses is totally false. Yes, many of the parts are replaceable in a tankless, but they aren't cheap and who knows if they'll be available when you need them. Where I live, the incoming water temps in the middle of winter are barely over freezing (I've measured it at 33-degrees). That will play hell with a tankless, either restricting the output flow radically, or lowering the outlet temp radically. Not something I want to deal with.

[master plumber mark]

If the model is a 125FX, read the last page for the maintenance schedule. Water filter need to be cleaned every year. Water valve needs to lubricated year 2, and needs a rebuild in year 3 to 5. Warranty is invalid if you skip that routine maintenance.

Sounds like the water valve is stuck on. Not sure why water is not flowing, but it is related to the water filter and / or the water valve.

Maintenance parts are pretty cheap. I keep a spare water valve, valve rebuild kit and lube in my plumbing kit!


http://www.boschhotwater.com/Portals/7/TechManuals/125FX_English_12_yr.pdf


Better check out the routine maintenance requirements on your new unit!


all of these units are nothing but trouble, and now that gas prices have tanked down to 62 a barrell they are less cost effective than ever.........

and you can only get along with them if you are capable of "un-conditoinal love"....

I cannot show that kind of love towards somenthing that expects me to kiss its butt every 6 months or so...with scheduled maintaince ect......


you are very very lucky that your house did not burn down,

you are very lucky that you were not scalded with steam when you poked your nose around the innards of the unit....

steam scalds are not a pretty sight especially around the face.....



but you are capable of "unconditional love" that I cannot
show ........and have gone out and bought another one...


turn the other cheek..... and hope that this one dont ruin your home....


good luck with the Rheem unit.


e

[Ladiesman271]

all of these units are nothing but trouble, and now that gas prices have tanked down to 62 a barrell they are less cost effective than ever.........

and you can only get along with them if you are capable of "un-conditoinal love"....

I cannot show that kind of love towards somenthing that expects me to kiss its butt every 6 months or so...with scheduled maintaince ect......
[



Better stay away from 90% + rated gas furnaces if that is your attitude!

Cleaning the water filter once a year is no big deal. Rebuilding the water every three years is no big deal either. Hardly maintenance every six months.

I installed my tankless years ago, and I am out only about $600 installed. Bought the heater at a bankruptcy sale, and installed it myself. It is a B vent unit with standing pilot, so no high tech crap to go bad.

A gas fireplace now sits where the old tank water heater was located. In my case I needed the floor space rather than needing to have the tankless!

[Ladiesman271]

Don't all tankless water heaters need some type of scheduled maintenance? Just wondering if anyone who owns one knows what the maintenance requirements are for their own unit.

[TheOak]

Just wondering how many people have needed to do that even one time in their lives.

My clothes washer is set for cold / cold operation, so the water heater is barely used for washing clothes.

I don't know anyone who ever runs the dishwasher while they are taking a shower.

Now some families may "need" to take two showers at the same time. That would probably be a killer for my tankless, but that is easy to work around!

Yes, you are right as far as an impossible scenario ... you missed my point though.

I have a large family. It is common to have two showers going at the same time, followed by other people wanting to shower, brush teeth, etc. This is a typical scenario in my home.

Thus far my tankless has run without a hitch under that load. Prior, when I had a tank ... I would be out of hot water in the middle of the third shower.

With the tankless ... it is like the Energizer Bunny ... it keeps going and going and going (bong bong bong bong) ... ;)

[TheOak]

I did not mean to imply that there would be any time that hot water would be used that way, I wanted to point out that a good 50 gallon water heater will supply continuous hot water for as long as you could possibly want to be using it even if it was for multiple uses. I'm sure that larger families might use more hot water at any one given time that we do, but for a normal household, it just isn't a problem.:)

I agree with this statement. I am not saying that tankless water heaters are the be all end all of water heaters and that everyone should have one.

With my family however (2 adults, 5 kids), I needed something that could keep up. My 50 gallon basic (no special venting, etc) natural gas water heat could not keep up. Thus far the tankless is running like a champ ...

[TheOak]

Don't all tankless water heaters need some type of scheduled maintenance? Just wondering if anyone who owns one knows what the maintenance requirements are for their own unit.

My Rinnai recommends you flush the unit out with vinegar at least yearly. I do not think it even mentions the inbound water filter, but at a bare minimum I would do that yearly too.

My furnace is right by my tankless. I have made a personal rule that whenever I change the air filter on the furnace, I will check the inbound water filter for the tankless. That should get it checked 2 to 4 times a year. Every third air filter replacement, the tankless will probably get a flush.

Prior to installing my tankless, I asked my installer for a reference. The person I spoke to was quite nice. He did make the comment that after about 6 to 9 months they noticed their hot water flow dropping. So they called the installer. The first thing he did was look at the inbound water filter. Sure enough, it was all plugged up. He simply gave the filter a rinse and a tap and reinserted. The unit ran like new again.

[TheOak]

all of these units are nothing but trouble, and now that gas prices have tanked down to 62 a barrell they are less cost effective than ever.........
...


I am not sure if there is a link between natural gas, propane and petroleum prices.

I will say though that my natural gas just went up about 20% from $0.97 to $1.16.

[Furd]

I think it is unfortunate that tankless heaters are getting all the R&D. In my opinion tank-type heaters are better able to meet the needs of most people and they have far less required in the way of maintenance.

The power vented tank-type water heaters are a step in the right direction. I think a tank-type heater with a flue damper, electric ignition and even two-stage burners (using dual thermostats like an electric water heater) would be the best of both worlds. After those improvements would come multiple flues to increase heating surface and better tanks that would not rust out. Final cost would probably be near that of a tankless but with lower installation costs and much longer (and more trouble free) life.

Just my opinion. ;)

BTW, there most assuredly IS a link between the prices of natural gas, propane and petroleum. Propane is a byproduct of refining crude petroleum and natural gas is often found in petroleum fields. Furthermore, the so-called petroleum companies, which are in reality ENERGY companies, control most of the production of all three fuels. The fact of your natural gas price having recently been raised has more to do with the time involved in getting rate adjustments through the state regulating commissions.

[TheOak]

Do they really get all the R&D though? Tankless heaters are not new. They have been around 20+ years (if not longer) in some parts of the world ... They are just "new" in North America ...

[gregsauls]

I looked at most brands out there, Bosch included, and found Bosch had some serious support issues. We settled on the Rinnai R75lsi and have loved it for our active household of 6. Down south, we don't have quite the same low inlet water temp issues to cope with.

I did install valves to allow easy descaling once a year.

Greg

[TheOak]

These were my findings too with regards to the Bosch units too unfortunately :(

What led me to Rinnai initially was when I was house hunting. I was shown a house by the builder himself. He stated he used Rinnai all the time and absolutely loved them and his purchasers too. Positive internet searches and local references sealed the deal.

With that being said ... if ... this Bosch unit had been serviced regularly (it sounds like it was not) ... we probably would not be discussing this now ... ;)

Just like cars ... a little service will go a long way regardless if the car is a Kia or a BMW.

[burleymike]

Years ago when we lived in the city and had gas service I thougt about a tankless, bosch to be exact. The price was soo much higher I just could not justify it. I sure am glad I did not.

Now living in the country we don't have gas service. The 10 year old electric 50 gallon water heater is probably full of scale. One bath and it is out of hot water for 30 minuets.

When I replace the rest of the galvanized plumbing I will install the new 50 gallon heater. I am thinking of keeping this old one and setting the temp to 80 degrees to pre heat the water for the new tank. In the winter when the incoming water is nearly freezing this will surly ensure a long hot shower or bath and shower.

I could buy several tank type heaters and still not spend as much as I would on a tankless.

[master plumber mark]

When I replace the rest of the galvanized plumbing I will install the new 50 gallon heater. I am thinking of keeping this old one and setting the temp to 80 degrees to pre heat the water for the new tank. In the winter when the incoming water is nearly freezing this will surly ensure a long hot shower or bath and shower.

I could buy several tank type heaters and still not spend as much as I would on a tankless.


If you use your old heater as a pre heater for your new heater , your new heater will probably last about 30 years...

I have run across that a couple of times
The pre heater tank warms up the water and takes the
stress off the new one...

better yet, take the outer jacket and insualtion off the pre heater



http://onsmartpages.com/weilhammerplumbingco/nss-folder/pictures/si_UEw80h80_DSC07866.JPG (http://onsmartpages.com/weilhammerplumbingco/pictures/view_alone.nhtml?profile=pictures&UID=10289) here is a 50 gallon electric tank
being used as a pre heater to the gas unit...

its 48 years old and was still working.

[varmint]

FWIW, about 10 years ago I installed an Ecotherm propane tankless unit- a friend, who'd been a dealer years ago, had one laying in his barn that had been sold, never installed, and returned to him around 1986 or so. I paid him $150, and plumbed it in, since our hot water was coming from an oil-fired steam heat boiler's coil, and I didn't want it running all summer (we are in Maryland, and don't need the heat from the basement). The most expensive part was buying the powervent kit from the distributor- CEC in New England- a good company. I have used it every summer, with minimal fussing, though I did have to replace the heat exchanger several years ago- which they sent me, under warrantee! Maybe I should have a filter, but our water seems clean and low-mineral, until now, anyway. (well water, and thanks to Exxon and a 26,000 gal. underground gasoline leak, our ground water is changing). It's a small heater, but fine for the two of us, and our low flow rate requirements. I think it makes sense to only heat water as you use it.

[houptee]

I installed 3 Takagi TK Jrs. I paid $600 each with free shipping from a company on the internet. The first year my gas bill went down $700, so they will pay for themselves in less than 3 yrs (since I installed them myself and hunted the web for lowest price). They have not required any parts yet in 2+ years so I am very happy with this brand, knock wood.

[SewerRatz]

I installed 3 Takagi TK Jrs. I paid $600 each with free shipping from a company on the internet. The first year my gas bill went down $700, so they will pay for themselves in less than 3 yrs (since I installed them myself and hunted the web for lowest price). They have not required any parts yet in 2+ years so I am very happy with this brand, knock wood.

Houptee, you wouldn't happen to work for Takagi or a sales rep?:D

Tankless water heaters are a hit or a miss thing. Lots of variables will determine if it will be reliable and how frequent maintenance must be preformed. So what may work for you just fine, will be headaches for the guy a few towns over.

[Dana]

Houptee, you wouldn't happen to work for Takagi or a sales rep?:D

Tankless water heaters are a hit or a miss thing. Lots of variables will determine if it will be reliable and how frequent maintenance must be preformed. So what may work for you just fine, will be headaches for the guy a few towns over.

The most common issues are related to water hardness & scaling, addressable by a de-scaling rinse every coupla years (more often in extreme hard-water cases) and annual filter cleaning.

The second most common seems to be freeze-control on the heat-exchanger in very cool climes (addressable with exhaust backflow prevention at time of installation- particularly important on side-vented units with short mostly-lateral venting.)

Nothin's perfect, but in real-world use tankless heaters are far more efficient than their tank-brethren. In many applications much more so than would evident in mere EF test numbers alone. To hit a tank's EF numbers you need to use over 60gallons/day- it's all about volume: NG & propane tank heaters have VERY high standby losses- a 0.66EF tank heater typically only delivers ~45-50% actual efficiency at daily volumes of 30 gallons, falling ever further with lower volumes.

With tankless heaters it's primarily about the length of burn in each draw. A tankless with 0.82EF may only deliver ~75% true efficiency if the bulk of the draws are less than 2 gallons, but it'll never be much below that. A single-person household who takes quick showers may only get 25% efficiency out of a tank, but will always get better than 70% with a tankless.

The only time a tank-heater approaches tankless efficiencies is the family of 8 that runs 3+ loads of laundry every night after the kids go to bed (and never goes on vacation.)

Payback periods are still highly dependent on fuel costs though. In the land of $0.60/therm NG it can take quite awhile... (especially if installed by a profe$$ional with an attitude. ;-) ) Installation isn't rocket science, but in many places DIY is strictly disallowed (or won't be indemnified by the property insurer unless installed by a licensed professional.) It's more akin to installing a wall-hung boiler than installing a tank heater. Combustion air requirements, gas plumbing size/lenghts, venting lengths & materials differ pretty dramatically from a typical tank install.

But compared to the cost of marriage-counseling about who gets stuck taking the cold shower when the tank runs out professional installation is a bargain! (Even installaion by an attitudinal-plumber!) The endless hot water aspect has it's charms- never met anybody who went back to tank after living with a tankless for awhile, even if they DID run into problems with the tankless or were annoyed by their quirks (the "cold water sandwich", etc.)

Still, for those with hydronic heating systems nothing quite beats the convenience & performance of a indirect-fired hot water tank running off the boiler. The summertime performance of an indirect won't often beat the tankless, but the annual performance usually will. Installation will usually cost less than a standalone tankless too. Without the central flue conducting heat out of the stored water 24/7 the standby losses of an indirect are quite low, and the combustion-efficiency is whatever the performance of the boiler is on delivering the tank recovery load (it'll be less than the AFUE number in summer, but adding the tank most often improves the average system-efficiency during the heating season.)

[FloridaOrange]

The only time I will specify a tankless heater on my plans is if directed to and there is a sever space issue, otherwise I'll push to spec a tank unit.