Greenwood Boiler 100

  • Active since 1995, Hearth.com is THE place on the internet for free information and advice about wood stoves, pellet stoves and other energy saving equipment.

    We strive to provide opinions, articles, discussions and history related to Hearth Products and in a more general sense, energy issues.

    We promote the EFFICIENT, RESPONSIBLE, CLEAN and SAFE use of all fuels, whether renewable or fossil.

JSeibert

New Member
Feb 3, 2022
5
Milaca, MN
My wife and I just moved into a home with a Greenwood hyrdonic furnace (100 series). We had moved into the home in December 2021. This is our first experience using this type of system to heat the home. The first 3-4 weeks we had been burning dried oak and it had been working fantastic to where I couldn't have been happier. Our issue that arose is that I started to notice that the wood wasn't really burning and started to build a very hot coal bed. When working properly the system was pretty easy to keep between 160-180. Once this coal bed started to form the heat dropped to 120 and I noticed that the fire had really changed. I decided to let this sit and clean the ash out, which I had been doing previously as well. This wasn't a situation where the ash had built too high. I pulled all of the hot coal from the stove and decided to try and clean this out. Using a wire brush I cleaned everything I could access. This allowed us to burn for about another 4-5 days before I started to notice the same hot coal bed. When you open the door, the fire rages and smoke just pillows out of the door. The minute you close the door the fire just disappears until you open the door again. Again, I can't get the furnace about 120 even though the hot coal bed that forms is plenty hot.

I cleaned the air intake with a wire brush, although the intake was not plugged. I cleaned the exhaust collar and chimney to where there is nothing built up. While there was certainly some ash and buildup in these areas it was nothing to suggest restricted air flow. I then checked the damper motor and everything seems to be operating as it should.

I have searched websites and watched videos. There isn't a lot of information out there outside of when Greenwood was still in business.

I was able to get in touch with the company who's number was on the furnace, but I am assuming they were just the supplier of said furnace and not necessarily who may have installed it. They confirmed for me that they themselves use similar furnaces and have to periodically clean this out. They suggested that I "pop" the sidewall off and clean out the area as I am probably restricting air-flow to the manifold. They specifically mentioned not to take the back of this off as there was too many pipes in the way to deal with.

My issue is that I cannot determine just how this would come apart. The sidewalls of this furnace are welded to the front. The only (easily) removable walls are the back.

Does anyone have any experience performing and cleaning or maintenance on the Greenwood Hyrdonic Furnace? I am currently running propane but we are experiencing -20 degree temps overnight and we wake up to a home at 58 degrees. I'm afraid with these temps that I am just flying through propane now that the furnace is out of commission. Again, I've cleaned the areas that I can reach and the air intake, exhaust collar, chimney, and damper motor seem to be ruled out from the issue. I feel as though the issue is behind the paneling that does not look removable.

Thank you,
Jeff
 
Any idea what the moisture content of the wood currently is? Did the type of wood (moisture) change?
 
Any idea what the moisture content of the wood currently is? Did the type of wood (moisture) change?
I do not specifically know the moisture content, but we bought kiln dried oak from a business I would trust. The wood I stored indoors so I hope it wasn't gaining any moisture content.
 
Thank you for the responses here. I'll be sure to check the moisture of the wood being used. I do not personally think my issue is deriving from the moisture content in the current wood stock. I understand I can check the moisture content going forward. I'm not new to burning wood, but I am new to the specific type of burner. I'm wondering if anyone else here has experience removing the panels or experienced anything similar with their Greenwood 100 and how they were able to resolve it.
 
I hope you get some decent feedback from someone familiar and experienced with a Greenwood. That's not me, but seems to me from memory of peoples postings, they were somewhat of an odd design and had their certain particular maintenance requirements. And I think they were messy. It sounds like a breathing problem to me. Which could be either intake path, or exhaust. I don't think you mentioned about cleaning the exhaust side except at the exit. I think I am fuzzily remembering people talking about creosote buildup around fire tubes? Googling should find something.
 
I hope you get some decent feedback from someone familiar and experienced with a Greenwood. That's not me, but seems to me from memory of peoples postings, they were somewhat of an odd design and had their certain particular maintenance requirements. And I think they were messy. It sounds like a breathing problem to me. Which could be either intake path, or exhaust. I don't think you mentioned about cleaning the exhaust side except at the exit. I think I am fuzzily remembering people talking about creosote buildup around fire tubes? Googling should find something.
I did find some information about cleaning the creosote buildup on the fire tubes. I cleaned these to the best of my ability with a wire brush and scraper as others have. These are also difficult to fully clean without removing the top, which par for the course it doesn't look like it was designed to remove easily.

I was only able to access the exhaust from the exit. I think you are right that I need to clean the rest of the exhaust, but there lies the issue. I can't seem to figure out how it actually comes apart without having to really break some welds to access this. I can remove the back panel, but again it requires taking a lot of piping apart. It may be my only option.
 
Watching
A friend has a green wood boiler,it was working good.
But he was used to a CB and was burning subpar wood,using plastic bags of paper to start the fire,
I haven't seen his but it ended up plugging up.Then he did a modification to get some heat out of it.
I would love to be able to give him some pointers
 
I can't say I have been around a Greenwood boiler but if you use the search box and put in cleaning the greenwood a lot comes up. In 2008 a posted with pictures cleaning a model 300. Lots of posts on the Greenwood. Might help you with your 100. Its hard to believe the previous owner didn't have the same problem. Usually you can see were covers have been off in the past. It does sound like they have air tubes that like to plug up. Good luck getting it going. I know how you feel I had to switch to propane last winter when it was minus thirty four because my Garn went to leaking.
 
  • Like
Reactions: clancey
Hi Jeff,

Unfortunately, the heat exchanger on your Greenwood may be plugging up. I don't own one, but have followed the posts about them over the years.

As you're finding out, they're not easy to take apart. This post probably has the best information about it that I've seen (and I think it may be one of those that Hedge Wood is referring to above), post #6

Also, later in that thread, they talk about the importance of keeping your return water coming back to the Greenwood at a high enough temperature to prevent condensation (could be a cause of why the heat exchanger is becoming plugged)

Here are more pictures of the before and after cleaning of a Greenwood, post #44

This person talks about using a camera, compressed air, some long brushes, and a lot of patience to clean the back of his Greenwood, post # 13

Good luck on getting your Greenwood working better again.
 
  • Like
Reactions: Highbeam
Hey everybody,

I was able to get the Greenwood working for now.

I had taken everything apart that I could and cleaned everything out. There really was nothing obstructing air flow, but there seemed to still be air flow issues. After I put everything together I decided to watch the damper to see if it was ever actually opening. The damper motor seems to be working fine, so this limited the problem to the auqastat. I pulled the motor off the damper door and adjusted it so that it stays open with a small gap. Once I changed this position the fire started to return to normal. I have been able to burn all weekend after making the adjustment and again being able to heat my home. My remaining issue is that I have basically found a work-around to get this working for now. I still need to take some time for a permanent repair but I am going to wait until the burning season ends.

Thank you everyone for their inputs. I'll be looking at the permanent repair and posting the results at that time.]

Jeff