Boderus Condensing Gas Boiler GB-142 with indirect hot water tank problems

LKC

Help! My high efficiency boiler and hot water system has been nothing but problems. (long post)
(long post)

I have a 2010 Boderus High Efficiency Boiler with an integrated 40 gallon hot water tank in an old house. It has radiators upstairs that probably date to the 1920s and baseboard heat on the main floor that date back to the early 1960s--three zones total, one up, two down--and quite a bit of excess piping in the basement covered in asbestos insulation. This system has a long history of different issues, and fails once every 1-3 years, despite annual maintenance. Some of them were installation problems, and the whole thing looks like a Rube Goldberg device. I am wondering if fancy technology is a poor match for an old house.

I recently did a lot of repairs to the system to fix areas that burst when the boiler control panel shorted out when I was away tending to a family emergency, and I also added heat to the kitchen, and enlarged and reconfigured a vulnerable zone.

In the past week the gas pressure control sensor failed and it took 2 days to replace, and then 2 days after that the hot water boiler failed. It is sending water the wrong direction, so water is pouring out the condensation tube right down the floor drain. So I had 2 days without any central heat at all and heated my whole 1,900 sq. ft. house with 8 space heaters, and now I have a house with heat, but no hot water. Thankfully no pipes burst this time. And the I am getting very little heat at the end of two zones and am still supplementing with space heaters there.

Anyway, now I am faced with an array of very expensive choices. I live in a rural area, so any company I pick only installs certain brands and there isn't any overlap. I am not terribly mechanical and have no idea which brand is best. Boderus invented the high efficiency furnace, but I've found German technology and American technicians don't always mesh.

I have to choose between 1) disconnecting the Boderus tank and forgoing the efficiency of a combined system to install a separate water heater (electric, power vent, tankless) or 2) getting a Boderus replacement for for about half of what we paid for the whole system 9 years ago, or 3) Replacing the whole works, for a different high efficiency combined system. High efficiency systems last only 12-15 years on average--mine might be less. Plus 4) I haven't yet checked, but maybe new separate systems of somewhat lower efficiency (and higher reliability?) is an option.

How do you tell if the tank itself has to be replaced? Can it be flushed out too? Can I replace just the tank and not all the other stuff connected to it? Does the tank have to be a Boderus? They are telling me installation is going to cost a bundle and take all day because they have to reroute water lines, and maybe replace or increase the size of the gas line. Only one guy I have talked to so far seems to really know about these things.

I posted this on another page and it was suggested that I need a system-wide acid flush (probably--don't know if they did that when they modified 2 zones 1 month ago), perhaps the 3-way valve to the boiler needs replacing, and maybe I can put another zone on the system just for the water heater. I read through the Archives here, and to top it off, maybe the existing system could have problems with bacteria because the water supply is shared. The guy who worked on it a month ago said that there was antifreeze in the system, but I was told before there was not and I would need a heat exchanger type device to keep the water in the heating system separate from water in the boiler. We had problems for years with inconsistent hot water temps, the colder it was outside the hotter the water was. After many complaints, I finally asked them to check the hot water pump and it was found to not to have any control over the water temps. Is the water in the heating pipes the same as the water in the tank? Now I am really confused and worried.

What should I do. All options are really expensive and I wonder if I am being sold a bill of goods. Any other suggestions or recommendations?

To top it off, I am dealing with lots of other building issues, and I really want to sell this place next summer. I really want to have no heating problems the rest of the winter, and I don't want to hand off a problem to someone else. Thanks!

EdTheHeaterMan

You can get any brand of water tank. In the industry we call that tank an INDIRECT water heater. There are several holes (Tappings) in the tank. 2 of the holes are the boiler supply and boiler return. They connects to the same pipes regardless of brand. There are 2 other holes. Cold water IN and Hot water OUT. Those holes are the same on every brand. Now the other holes are where the relief valve might go and the temperature probe might go. A competent installer will figure that out. With the Buderus control system, you have an electronic temperature sensor at the end of a wire that connects to the boiler control. there should be a hole at the bottom to drain the tank, unless you are unlucky enough to find an old Weil McLain Plus-40. (don't worry, they were discontinued). Depending on the brand of tank your installer selects, you may need a well adaptor to plug up the temperature control opening and have a place to insert the temperature probe.

You might want to check with a supply company that sells Buderus Boilers, You might have warranty coverage left on the tank.

Ironman

If the system has anti freeze in it, and if it's not the specific type that's compatible with aluminum, then that could be the cause of your aluminum heat exchanger failure.

Ironman

if you have cast iron rads and fin tube baseboards, they should never have been setup together on the same SWT zone. CI rads require a much lower SWT due to their high mass; BBs require a high SWT due to their low mass.

Seeing this indicates that the people that installed this, as well as those who serviced it, didn't have the level of competency needed for this type of system and that may well be the cause of a lot of your woes.

Everyone blames the equipment when 95% of the time it's the "technician".

lchmb

so it sounds like the coil in your indirect has failed. Has anyone checked on the tank warranty? If it is not under warranty any tank can be used to replace it. It's not inexpensive but it should be a simple in and out job. The boiler is not the issue, at least not yet.. I'd do the tank if it were my house. Get a tank with a lifetime warranty..

LKC

Thanks for your input. The upstairs with the radiators and the downstairs with the baseboard heat are in separate zones. The downstairs is two zones and one zone has a new hydronic toekick heater.

I know what you mean by the thermal mass. Last year the wiring went out on the thermostat upstairs and it was awful to have the zones combined. Blazing hot upstairs and freezing cold downstairs. Then when they replaced the wiring a month ago, the zones were still connected until I complained about it.

Yes, I get the feeling that the people servicing this don't really understand it, but in an emergency, you take what you can get. I used to ask for the one guy who seemed to know this system, but he no longer works there. This has been one problem after another.

The gas pressure sensor and unit went out less than a year after it was installed and we were charged for its replacement even though it was under warranty. I found out later it was covered and it took a year of phone calls and emails to get the refund. That put a pretty bad taste in my mouth, but I'm stuck because they are the only company to service this brand here. Two years after that, I finally got the water system pump replaced so we didn't have boiling hot water coming out when it was cold, even if we reset the temperature of the tank. The next year it started to cut off without warning, and it took a service call to start it up again. Then the Boderus trainer came to my house and spent most of the day trying to figure out what was wrong and ended up replacing every sensor in the system. Then two years ago, the control panel shorted out. The following year, the thermostadt wiring went. Has been OK since then until last week.

I was quoted thousands of dollars to replace the tank with a Boderus tank, and that sounded really high to me. I'll ask if they can use a different tank, but I don't know if anything else is wrong. It is 9 years old, so I doubt it is still under warrantee.

If I sell the house, is a lifetime warrantee still valid?

EdTheHeaterMan

Limited lifetime warranty had limitations. Check the fine print. It might end in 20 years to a new owner. Lifetime may also be pro-rated to the original owner.

Ironman

I think you're misunderstanding what I meant by two supply water temp zones. You have two zones, but they are supplying the same water temp to both of them. You need to have a cooler water temp supplied to the cast iron rad's. This requires an additional mixing device beyond the boiler. The cast iron rad's probably don't need more than 150* on the coldest night of the year while the BBs probably need at least 180* SWT on the coldest night.

Regarding the shorted control panel: it was probably caused by the shorted thermostat wires.

The life expectancy of the Buderus indirect, or any other indirect, depends on the condition of your water and if the anode rod has been checked and maintained.

I'm very familiar with that boiler, but I don't know what you're referring to when you say the "gas pressure sensor".

LKC

They told me the sensor was to detect the incoming gas pressure because this unit, unlike American boilers, is really finicky about that. Maybe I misunderstood, that is what happened when we first got it, so maybe the sensor was for something else. This time, if replacing the "pressure sensor" didn't work, the next step was to replace the UBA 3. The error code was CO 288.

I was told a piece of metal detached and shorted out the system. I was out of state when it happened almost 2 years ago. A friend was checking the house everyday and her heroic actions saved my house from a total catastrophe. The thermostadt wire failed a year after that, after I had drywall installed over the plaster around it.

Now I see what you mean about water supply temperature (is that what SWT means?). I should ask about that. More $$$. We keep the upstairs a little cooler than the downstairs and it hasn't been a problem until recently. But I had to do a full mold abatement upstairs in less than ideal conditions and air it out with open windows and the temps soared downstairs. I knew it was because the thermal mass is so much greater upstairs and I had to completely seal it off from everywhere else in the house (I turned everything down as low as possible, but high enough to keep the water circulating, and closed the windows at night and when temps dropped below 40 degrees, and only cracked them when it was that low). That was about 6 weeks ago.

The tech was unsure which pipe went upstairs--it is buried in a chase behind a wall in front of the house I think. It is quite a maze in the basement. I assume they can figure it out, but the old pipes are wrapped in asbestos and they won't touch them. The nearest abatement company is 3 hours away.

I really have no confidence in this company and this boiler. But I'm stuck with it. Do you think I would be better off installing a cheaper but less efficient boiler and hot water heater (with another company)? That is what we had before, but it was very old. Like I said, I think a lot of this has been installation and technician issues because the system is too complicated, and now I don't think they even get training for it. Now they are recommending a Bosch for big bucks. The guy who was OK with my system is no longer with the company. What I hear depends on who I talk to.

My house in only worth maybe $120,000 once I repair everything, (I've got structural damage from a failed roof plus other stuff) and I really don't want to spend 10% or more on the heating system! Especially since I only want to live here for another 6-9 months!!!

We have tried so hard to be good homeowners but have had problems with the most expensive repairs we have done--the roof was installed improperly, and I think the heating was too. Both companies were recommended to me by the previous owner's daughter and her husband, who had lived in this town their whole lives and used them in building their own home. What a mess!

Ironman

LKC said:

They told me the sensor was to detect the incoming gas pressure because this unit, unlike American boilers, is really finicky about that. Maybe I misunderstood, that is what happened when we first got it, so maybe the sensor was for something else. This time, if replacing the "pressure sensor" didn't work, the next step was to replace the UBA 3. The error code was CO 288.

I was told a piece of metal detached and shorted out the system. I was out of state when it happened almost 2 years ago. A friend was checking the house everyday and her heroic actions saved my house from a total catastrophe. The thermostadt wire failed a year after that, after I had drywall installed over the plaster around it.

Now I see what you mean about water supply temperature (is that what SWT means?). I should ask about that. More $$$. We keep the upstairs a little cooler than the downstairs and it hasn't been a problem until recently.

The gas pressure sensor is a new on me for a gb142. We've installed many on LP and never had the problem of the unit being "finicky" about incoming pressure. In fact, quite the opposite is true: the gb142 is one of most forgiving units concerning incoming pressure. If your gas lines are properly sized, and the regulators are set correctly, there should be little or no fluctuation in incoming pressure.

Here's a link to Buderus' instructions for converting to LP. There's no reference whatsoever to installing a gas pressure switch.

https://s3.amazonaws.com/s3.supplyhouse.com/product_files/Buderus - 76687 - Install Instructions.pdf

As far as creating two SWT zones: if you selling the place, I wouldn't be concerned about it.

woobagooba

We have the same boiler and looks like the same indirect tank. Though your boiler does have the newer design primary manifold underneath.

Mine are about 10 years old. Indirect has failed, boiler is on its last legs.

Might be helpful info here ...

https://forum.heatinghelp.com/discussion/170834/buderus-gb142-multiple-corrosion-issues

https://forum.heatinghelp.com/discussion/170930/buderus-s120-indirect-tank-not-looking-good