Good afternoon Hearth community. Looking for a little insight on why my Tarms solo 30 wood boiler keeps overheating. It just started with the last two years so I reached out to Scott at Tarms Bio Heat in Orford, New Hampshire. We went over some of the problems we thought could be the issues, and we narrowed it down to replacing the tamover mixing valve. so I fired up the wood boiler And overheated within the first hour with very little wood in the firebox. I know this is a longshot, but does anybody know of a service tech that knows how to install or work on these particular boilers from what I’ve been reading there isn’t any. Could use the help. Please advise.
Tarms Solo 30 boiler over heating
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?? It’s right next to my existing house furnace. For the first 14 years it worked fine not too sure what the problem is.
Just a wag but I know on my 40 after the fan shuts off the temp continues to climb a bit, maybe your fan shuts off at too high a temp. But thinking about that you can always turn it down a bit unless you already have tried that.
If you get him to answer the phone, Kevin Rines in Gorham (K&R heating) has installed Tarm wood boilers in the past. He is trying to retire and picks what he wants to work on. I took out one he installed in Randolph a few years ago. My guess is your Thermovar unit is not working correctly, what it is supposed to do is recirculate all the water coming out of the boiler back to the inlet of the boiler when its cold and then slowly start to open up third port on the valve to send hot water to the heating system as its warms up over 130 deg F. I have never messed with a Thermovar as my Burnham boiler does not have one. I think that Thermovar valve has a rebuild kit as it operates off of an internal component that expands and opens an outlet valve when hot water is run through it. If that internal component has failed, the valve will fail in the recirculating position making the boiler overheat. I think the internal parts are pretty complex and there could be crap inside it. Tarm in Orford sells a couple of varieties but they may not be able to get a kit.
Make sure that there are no hand valves closed on the inlet or outlet of the boiler. I always use ball valves if I can as the standard globe valves with handwheels on occasion break in random position. BTW, Tarm have not been sold for awhile so my guess is the unless its a used unit that has been moved around its an older installation and needs attention.
The one I took out was piped up very simply with no thermal storage, it definitely needed a thermovar but once thermal storage is added the need for a thermovar is far less important.
A general observation is that in most areas a home owner is on their own on working on wood boilers. Tech schools crank out burner techs for natural gas, propane and heating oil. They are clueless on wood boilers. The other aspect is that there are many ways to install a wood boiler and over the years many were installed poorly. Even Tarm sold a lot of boiler without Storage until the figured out that the gasifiers just do not run right without it and they stopped guaranteeing installs without storage like the one I took out in Randolph. There are just not that many wood boiler installs these days and the people who did specialize in them are mostly retired. Since the installations are all different it sometimes takes a few hours to figure out what the original installer was thinking so service calls on a new system will be expensive and usually will mean a second visit after parts are tracked down. It comes down to if you dont become your own technician you are probably going to be waiting a long time to get someone competent to work on them.
Make sure that there are no hand valves closed on the inlet or outlet of the boiler. I always use ball valves if I can as the standard globe valves with handwheels on occasion break in random position. BTW, Tarm have not been sold for awhile so my guess is the unless its a used unit that has been moved around its an older installation and needs attention.
The one I took out was piped up very simply with no thermal storage, it definitely needed a thermovar but once thermal storage is added the need for a thermovar is far less important.
A general observation is that in most areas a home owner is on their own on working on wood boilers. Tech schools crank out burner techs for natural gas, propane and heating oil. They are clueless on wood boilers. The other aspect is that there are many ways to install a wood boiler and over the years many were installed poorly. Even Tarm sold a lot of boiler without Storage until the figured out that the gasifiers just do not run right without it and they stopped guaranteeing installs without storage like the one I took out in Randolph. There are just not that many wood boiler installs these days and the people who did specialize in them are mostly retired. Since the installations are all different it sometimes takes a few hours to figure out what the original installer was thinking so service calls on a new system will be expensive and usually will mean a second visit after parts are tracked down. It comes down to if you dont become your own technician you are probably going to be waiting a long time to get someone competent to work on them.
Yes I’ve try that. It blow my mind that you can find someone that has worked on these in the past in the whole north country!!
LIke Peakbagger says got to do it yourself. Maybe with a hand held thermometer that you could point at the piping you could figure out what's going on.
Thanks for the info. The tarmover was just replaced last week. Very pricey $140.00 with rings. I've had this unit since 2014 on its run flawlessly. Just in the past couple of years it’s started acting up. I really don’t think it’s anything serious. I had the guy who put the boiler install the new tarmover. It odd that it ran fine for 12 years. I’m going to touch base with him in th AM. The problem is he’s extremely busy. Just need someone who can possibly troubleshoot. I’ll see if Kevin is interested in taking a look.
When I look on the woodboilers.com website this boiler could be one of several models, they all seem to be a variation of the same concept with different details. It would help everyone to help you if you were specific on what model and date as some of the models seem to have variations based on the date of manufacture. Timing wise if it was new boiler when installed it was into the Innova era when Tarm was no longer building them and just acting as the distributor. Hearing that it ran flawlessly for 8 years and then seems to have become a problem in the last two or three years is the key. Has the heating demand gone down in the last few years?. Has the use of the home changed?. Anyone recently retire ?
One other question is this a typical close loop boiler system with an expansion tank?. Boilers and their pumps will not last long if the system is run open loop where hot water is being taken directly off the boiler. There is automated feedwater valve on the boiler but it should be closed nearly all the time. Relief valves and pump gaskets can leak on occasion and that is what the feedwater valve is intended to cover but if there are lot of leaks, it can lead to internal corrosion of the boiler and sediment build up.
Given the age, the folks in Orford reportedly did not guarantee installations without thermal storage for a reason. This design really only wants to be on/off. Sure, its got thermal mass which hides it but once its in gasifier mode it wants to run at high heat output and there has to be somewhere for the heat to go nearly all the time, if it doesnt have that heat demand its going to have a tough time. But the question comes up what has changed that it was running great for 8 years and then started acting up?
Do you know why the thermovar was rebuilt?. Were you having the same overheating issues, what were the symptoms? Same question about the circulator pump, why did it get swapped?. Circ pumps run a long time if they were installed correctly, if they were sized wrong or piped wrong they dont last long and are normally noisy. In some rare occasions usually related to corrosion the pump impellers will corrode away but that is pretty rare on closed system.
Tarm's have an overheat system that dumps heat to a dump zone, as long as the circulator was properly sized and the dump zone is working, the boiler should never overheat, if the dump zone opens up, the boiler has already tried other things like shutting of the air supply so it would be helpful if you could describe exactly how "it overheats" Does the pressure relief valve open up? Does the dump zone come on?. Does the air shut off so you have an unburnt load of wood inside?.
IMO, most wood boiler overheating issues are usually external to the boiler and it usually comes down to either the hot water generated by the boiler is skipping the house and going right back into the boiler or the pump is not moving the water fast enough to take away the heat. If the pump was sized correctly when installed and ran fine for several years then its probably not the pump selection. If the system is full of air, the pump will be quite noisy and will eventually destroy itself due to cavitation in matter of weeks. In rare occasions the zones cold be air bound so that the heat does not get out to zones and recircs back to the boiler without heating the house and ultimately overheating the boiler. This is usually apparent early on when boiler is first being run or later on after major repairs to the boiler. My parents had an oil boiler with that issue and once I put in air purge on the zone returns the problem went away.
One other question is this a typical close loop boiler system with an expansion tank?. Boilers and their pumps will not last long if the system is run open loop where hot water is being taken directly off the boiler. There is automated feedwater valve on the boiler but it should be closed nearly all the time. Relief valves and pump gaskets can leak on occasion and that is what the feedwater valve is intended to cover but if there are lot of leaks, it can lead to internal corrosion of the boiler and sediment build up.
Given the age, the folks in Orford reportedly did not guarantee installations without thermal storage for a reason. This design really only wants to be on/off. Sure, its got thermal mass which hides it but once its in gasifier mode it wants to run at high heat output and there has to be somewhere for the heat to go nearly all the time, if it doesnt have that heat demand its going to have a tough time. But the question comes up what has changed that it was running great for 8 years and then started acting up?
Do you know why the thermovar was rebuilt?. Were you having the same overheating issues, what were the symptoms? Same question about the circulator pump, why did it get swapped?. Circ pumps run a long time if they were installed correctly, if they were sized wrong or piped wrong they dont last long and are normally noisy. In some rare occasions usually related to corrosion the pump impellers will corrode away but that is pretty rare on closed system.
Tarm's have an overheat system that dumps heat to a dump zone, as long as the circulator was properly sized and the dump zone is working, the boiler should never overheat, if the dump zone opens up, the boiler has already tried other things like shutting of the air supply so it would be helpful if you could describe exactly how "it overheats" Does the pressure relief valve open up? Does the dump zone come on?. Does the air shut off so you have an unburnt load of wood inside?.
IMO, most wood boiler overheating issues are usually external to the boiler and it usually comes down to either the hot water generated by the boiler is skipping the house and going right back into the boiler or the pump is not moving the water fast enough to take away the heat. If the pump was sized correctly when installed and ran fine for several years then its probably not the pump selection. If the system is full of air, the pump will be quite noisy and will eventually destroy itself due to cavitation in matter of weeks. In rare occasions the zones cold be air bound so that the heat does not get out to zones and recircs back to the boiler without heating the house and ultimately overheating the boiler. This is usually apparent early on when boiler is first being run or later on after major repairs to the boiler. My parents had an oil boiler with that issue and once I put in air purge on the zone returns the problem went away.
Hi
My guess is the water isn't moving as it should.
When i fired up mine this year for the first time it run till the high limit aquastate shut down the fan.
I assumed since it was fine in the spring while it was running that it should be fine in the fall as well.
It turned out to be airlock due to being down about a gallon of water.
My guess is the water isn't moving as it should.
When i fired up mine this year for the first time it run till the high limit aquastate shut down the fan.
I assumed since it was fine in the spring while it was running that it should be fine in the fall as well.
It turned out to be airlock due to being down about a gallon of water.
Do you have storage? Because I don’t. How did you determine that you were down a gallon of water
? When I talk to Scott at Tarms, Bio Heat he said most likely it’s not the circulating pump. He mentioned to me to make sure the fan door when the fan shuts off that it is fully closed as well as the damper door to make sure that’s not sucking any air but I’m curious how you figured out that you were a gallon down. Please advise.
? When I talk to Scott at Tarms, Bio Heat he said most likely it’s not the circulating pump. He mentioned to me to make sure the fan door when the fan shuts off that it is fully closed as well as the damper door to make sure that’s not sucking any air but I’m curious how you figured out that you were a gallon down. Please advise.
Yes i have storage
The sytem pressure was still at zero while it was warm. I have just enough pressure tank for when the system is hot.So i added some water and it was fine after.
The sytem pressure was still at zero while it was warm. I have just enough pressure tank for when the system is hot.So i added some water and it was fine after.
Just wondering as it seems no one has asked is it heating your house? If so it would be circulating fine. Plus we talked about the fan and what temp you have it set at, what temp does the fan shut of at? Maybe the temp control on the furnace is screwed up as nothing lasts forever. Just a couple ideas.
Just doesn't seem to me that it could overheat if the fan shuts off say at 180 unless there's some pretty big air leaks. That fan should shut off at whatever you have it set for. But I'm far from a boiler expert.
I have a Tarm Solo Plus 30 also. Because your boiler worked ok, check to make sure the draft fan flapper is closed when the draft fan is off. It's under the top front jacket panel. this flapper can get stuck open when the boiler has a large blowback. A good thing to do when cleaning the ( one's a year ) is to take your wife's tooth brush and clean the fins on the draft fan. Ok something else to look at is the temperature gauge is that the actual temp of the water, the gauge reads in celsius. The last thing that I can think of is the operating thermostat on the front of the control panel that you can adjust. I use a portable temperature gauge on my boiler to make sure the temp that you are seeing is really the temperature. You could use a infrared gun to check your temp. Hope this helps. You should hear the draft fan shut off when the temp is close to 170 or 180 degrees.
Thanks for your advice on Solo 30. I would like to inform everybody that I finally figured out the problem! Through process of elimination and help from all the good folks out there I believe the problem was one of the three doors heat exchange, firebox, and the clean out door. I replaced all the gaskets. I believe one of though doors was sucking air and causing it to over heat. I checked the fan door and that was working properly. So last month I change the time over and then purchased all the gaskets. Roughly $400. But well worth it. Thanks again for all your help.
Does your boiler have a gasket for the cover where the tubes are? Mine doesn't and it seems like it should have.
It does. That makes sure it’s airtight. Is your boiler overheating at all? It should have a little little seam gap around the outside of the door. That’s where that rope gasket would go. If you can send me a picture I can tell you definitely if it should have one or not.
Maybe we're not talking about the same thing. I'm talking about the cover that has 4 wing nuts that have to be removed to get access to the tubes for cleaning. It's a flat plate that sits on a ridge around the opening, just metal to metal. No place for a gasket. Maybe yours is made different, I just thought they'd be the same
brenndatomu
Minister of Fire
I have the same plate with the 4 wing nut actually my boiler is a solo 40. Same thing as a 30 but made put out more BTU’S. Can you take a picture and send it to me so I can see? I just cleaned my he exchange tubes last week. And it’s the same thing as mine. There should be a gasket in there. I replace mine three weeks ago. Mine has gaskets on all my doors. Clean out where are you? Clean the heat exchange tubes and the firebox. All mine have gaskets. If you want to talk here’s my contact info
Doug Capute, 603-361-5765. Up to you.
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