Anyone out there repaired or rather replaced the firebox of a Tarm? In February we holed our Tarm 2000. That was after 16 seasons, but I was hoping for 30. Actually bought from Craig in 1992. It developed leaks in the back wall. There is general thinning of the wall. Originally ¼” plus, now about half of that. The leaks were at the weld-through “Stays”. Air inclusion in the welds. The side walls are in better shape but do not trust the welding of the stays and there is metal loss there too. Nichols Hardware has offered me a reasonable price on a replacement – the Solar Plus but I am loath to throw out a good old heat plant when everything else works pretty well. And the new Tarm is an add-on boiler so does not have the electric stab heater package that we use (at low setting) to keep things from freezing up in the winter when we are gone. Not to mention cannot ship to Washington State (or California) due to some air quality reason. I digress. To the original question: Has anyone replaced a Tarm firebox that could share some details? Think that I would probably go back in with some stainless, a bit of a shortcoming on the original in my view. Any thoughts? Thanks
Tarm Repair?
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I think it could be difficult to track down all the possible thinning and leaks. You can often get away for a couple seasons with boiler stop leak and very local repair. But if you get a good deal on a new one.....I'd take it!
The boiler will last much longer if storage can be added, because the worst acids are produced in the idle mode. This is something that was learned back then, as competitors boilers (Eshland, etc.) were giving out in 4-5 years. Tarms were built better and used superior steel, so they tend to last longer in any case, but nothing can stand up to those heavily corrosive acids.
In a real pinch, it might be possible to repair such a boiler and convert it to non-pressure (or extremely low) pressure use (with a HE) and thereby get a bunch of more years out of it.
The boiler will last much longer if storage can be added, because the worst acids are produced in the idle mode. This is something that was learned back then, as competitors boilers (Eshland, etc.) were giving out in 4-5 years. Tarms were built better and used superior steel, so they tend to last longer in any case, but nothing can stand up to those heavily corrosive acids.
In a real pinch, it might be possible to repair such a boiler and convert it to non-pressure (or extremely low) pressure use (with a HE) and thereby get a bunch of more years out of it.
Sounds like your leak is the tip of the iceberg. Usually that's the way it goes. Most welders won't touch an old boiler.
Do you have any low temp return water protection plumbed into the boiler? They say that when the return water temps drop below 120 or so, it allows moisture to form on the inside of the firebox, which mixes with the acids Craig mentioned and over time, will flake off enough metal to get the kind of thinning you mentioned.
Do you have any low temp return water protection plumbed into the boiler? They say that when the return water temps drop below 120 or so, it allows moisture to form on the inside of the firebox, which mixes with the acids Craig mentioned and over time, will flake off enough metal to get the kind of thinning you mentioned.
As Eric suggest, there are two ways the leak can be caused by - from the inside and from the outside. One (inside) is the result of return water that is too cold, while from the outside it is the acids.
Thanks for the interest in my problem. Did think about welding a plate over the back wall but the stays actually in the way, and they protrude in from the side walls too. Gave up on that idea. My thought was to cut out the boiler top (cutting the top stays through the domestic water heater hole). Then move right down into cutting out the firebox. Have good thickness lower down in the area of the ceramics, so that is were one could build back up from. But I was hoping to find someone that has done this before. My original thought was that Tarm would have a repair procedure, but that thought was quashed by Scott at Nichols Hardware. The US market is little more than an afterthought with Tarm so would have no luck talking to Tarm.
To some other questions, comments. The thinning was from the inside the firebox. Probably trying to run too late into the spring. Sometimes didn’t shutdown until May or even June, weather is so variable around here. Nice day today but who knows tomorrow. So probably too much idle time in the early days, but who knew. The last few years have been shutting down about April and just running the boiler electric heaters for the back of the house which is well insulated and putting a fire in the stove in the living room when we needed it. But damage was probably already done and having faulty welds on the Stays didn’t help.
I was going to attach some pictures, but the file size is several times the 350kb allowed. Is there some software that shrinks the picture file? Will attach on the next post. To Eric’s comment on water temperature. Generally 180-190F unless for some reason run out of wood and that was very seldom. Probably only restarted the boiler 3-4 times in a winter. The boiler was plumbed into a 4-way mix valve, boiler water circulating on one side and water to the in-floor heat circulation on the other. Water on the house side probably 80-90F varied inversely to outside temperature by 4-way valve controller. Will attach a picture of that too and the boiler in happier times. Would expect boiler return temperature to be just a few degrees under the boiler supply temperature due to water circulation rate. No more than a slip stream going to the house and coming back.
Quite a write-up here. A picture is worth a thousand words as soon as I get that figured out. Later.
To some other questions, comments. The thinning was from the inside the firebox. Probably trying to run too late into the spring. Sometimes didn’t shutdown until May or even June, weather is so variable around here. Nice day today but who knows tomorrow. So probably too much idle time in the early days, but who knew. The last few years have been shutting down about April and just running the boiler electric heaters for the back of the house which is well insulated and putting a fire in the stove in the living room when we needed it. But damage was probably already done and having faulty welds on the Stays didn’t help.
I was going to attach some pictures, but the file size is several times the 350kb allowed. Is there some software that shrinks the picture file? Will attach on the next post. To Eric’s comment on water temperature. Generally 180-190F unless for some reason run out of wood and that was very seldom. Probably only restarted the boiler 3-4 times in a winter. The boiler was plumbed into a 4-way mix valve, boiler water circulating on one side and water to the in-floor heat circulation on the other. Water on the house side probably 80-90F varied inversely to outside temperature by 4-way valve controller. Will attach a picture of that too and the boiler in happier times. Would expect boiler return temperature to be just a few degrees under the boiler supply temperature due to water circulation rate. No more than a slip stream going to the house and coming back.
Quite a write-up here. A picture is worth a thousand words as soon as I get that figured out. Later.
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