Cleaning the Greenwood w/pics.

I started the spring cleaning of the Greenwood today. Dismantled, moved and opened her up. For those Greenwood owners that are interested, I will post some pictures and give a short description once I finish the cleaning.

Hi Pete,

Looking at your installation photo in another thread, it looks as if your unit is not easily moveable. I was able to disconnect the plumbing and chimney at the back of my unit and then lift the GW with a pallet jack moving it forward and out of the way. I did have to cut one of my small copper pipes leading to a dump zone that did not have a union, otherwise, I disconnected the plumbing at the union leading to the flat plate HX and at the base of the Greenwood circulation pump. Most of the electrics had to come off as well. When I put it back together, I will see if I can install unions on the GW on the main heat exchanger. Once I finish up the cleaning, I will write up a detailed description of how I did mine with pics.

Here is a quick step by step of the procedure that in used to clean the heat exchanger on my Greenwood 200. Please note that the accumulation of fly ash and creosote only happened on the heat exchanger. This is believed to be the result of low water return temperatures to the exchanger. I am having my system modified to prevent the cool water from entering the exchanger, thus hopefully, preventing the same next season. In addition to the previously mentioned modification, I am adding two unions at the connections to the heat exchanger so that I can quick disconnect the plumbing if required to access the back of the unit for future cleaning.

Step 1. Disconnect all of the plumbing to be able to remove both the top panel and rear panel on the unit. I disconnected at the circulation pump and at the heat exchanger as both had unions for easy removal. I then used a pallet jack to move the unit into a clear area.


Step 2. Remove all screws and eye bolts and lift off top. Note - The top may be difficult to lift if the insulation has stuck to the heat exchanger tubes as a result of creosote and/or condensation. Go slowly and try not to damage the insulation.


Step 3. Remove bottom panel on rear of unit. Pull straight back off the bolts and the air intake tubes will be free of the refractory.


Step 4. Remove upper rear panel. Note - there is a 12" deep piece of insulation that lays on the bend of the heat exchanger that is attached to the top of the rear panel. Be careful to free the insulation from the heat exchanger tubes if sticking prior to removal of the rear panel to prevent damaging the insulation.


Step 5. Start scraping off the heat exchanger tubes with, ideally, the cleaning tool being produced by greenwood. It works well in combination with a stiiff narrow paint scraper. Plan on a few hours of scraping depending on how bad your unit is. Mine took about 5 hours of scraping.


Step 6. Put it all back together and modify your system so that the heat exchanger is protected from cold water return. Be sure to put back the insulation exactly as it was when you took it apart. Pictures help.

I am hoping that the pics went in the correct position after each step. This is my first time attempting the embedding of pictures.

Hi Sparke,

I just posted a brief description on a new thread called "Cleaning the Greenwood w/pics.

Hi Be Green,

The majority of the wood was around 11%. Some went as high as about 18%. It was all beetle killed spruce and or pine. This was my first year operating the boiler and i am hoping for a much cleaner burn next year as I feel that I have climbed a fair distance up the steep learning curve. I forgot to post a close to being finished cleaning pic.

Hi Steve,

I don't have a temperature gauge on the return water pipe from the external heat exchanger going into the boiler, but I have been told by Greenwood, that this return water must not be less than 130 - 135 deg F., otherwise ,the heat exchanger will collect creosote. The worst build up is at the base of the Greenwood heat exchanger where the return water enters. The boiler output temperature does not really tell you what your return temp is as there are many variables. If you let your fire go out and have to restart, you are pretty well assured that your return water temp is too low. How clean is your heat exchanger?

sparke said:

Nice documentation Dkerley. What did you do for return protection? Termovar?

Click to expand...

Hi Sparke,

I have been told by Greenwood and by the plumber that did my installation, that there are several different options for return protection. I still have my unit's plumbing apart waiting for the plumber. I believe that he is proposing installing a couple of "T's" in both the supply and return from the external HX coupled with a pump and a temperature gauge and a few other parts. Greenwood is putting together a modification kit that should be ready very soon through their parts department.

stihlwoody said:

Doug, I will have a better idea about clean after I feel comfortable with outdoor temps, but from taking off the stove pipe and peering up inside with a mirror, I think I am pretty clean. The picture of the rear of your hx is a eye opener though. With 300 gallons of storage I didn't see return temps less than 140 most of the winter. Hope to up size to 800 gallons over the summer.

Steve

Click to expand...

Hi Steve,

I am glad that you may have burned clean. If I am not mistaken, I think that you are burning primarily birch. I was burning very high pitch wood both beetle killed spruce and pine. Not sure if that makes mine more susceptible or not. I too am looking at water storage as a potential option for the shoulder seasons but only because I would also like to add a couple of solar panels for the DHW during the summer.

roaring fire said:

Doug thanks for shedding light on the the back of those water vessels
If low water temps are causing all this creceote we are killing those boilers
during the shoulder season by doing a cold start up each day. I thought
the main culprit was burning green wood but your report of 11 to 18%
is good dry wood in my book. Fred Seton said he has sold this design for 20
years & I am hauntingly reminded of a remark by the Webmaster ... in all the time
he sold Tarm he had not heard of Seton. This design ,which is at the heart of the beast,
is not going to cut it, if the manufacturer can't come up with a user friendly way
of cleaning those vessels.
The annual regular maintenance recommended by Greenwood , Seton make
no mention of cleaning the vessel, out of sight out of mind I guess.

Click to expand...

Hello Roaring Fire,

Greenwood has issued a technical bulletin regarding cleaning of the heat exchanger. There are definitely plans to attempt to prevent the accumulation of creosote plus some form of improved access. I have no affiliation with Greenwood whatsoever, found out about them by surfing the internet after the insurance companies would insure an OWB on my property (too many trees). I believe that this is a good product that needs a little tweaking to make it a great product. Where I live, I am having to deal with temps as low as -50 in January to above freezing in the shoulder months. Even my high efficiency propane forced air furnace wasn't optimized for the extremes.