Flue Condensation - Solo Plus 60

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jw4984

New Member
Jan 10, 2019
11
Rhode Island
Hi all. I purchased a house with a Tarm Solo Plus 60. This is my first season using it. I have been burning for about a month now and feel pretty comfortable with it.

I have a question regarding chimney flue condensation.

Here is my set up. The Solo Plus 60 is tied into my oil boiler and indirect fired hot water tank. I have a masonry chimney on an exterior wall with three flues. One for the oil boiler, one for the solo plus and one for a fireplace. There is also a draft inducer fan attached to the smoke pipe. I do not have any water storage.

I have the boiler fan set to kick on when the temp drops below 180 F, per the instructions. When the boiler fan kicks on, the boiler temp rises to 190 F, this is also consistent with the instructions. When the wood is burning I get consistent flue temps of 550 to 600 F. This is perfect as I read in the instructions. Then when the boiler fan shuts down the flue temp drops to about 150 to 175 F. The draft inducer fan on the smoke pipe is always left on low (previous owner told me to do this).

The Solo Plus is heating my house great. However, I have been noticing condensation coming from the chimney flue servicing the Solo Plus. I see it when I open the ash clean out door which is located below the smoke pipe to the Solo Plus. Over time, I have been noticing some water pooling on the floor of my chimney ash clean out. I cant tell if the condensation is also forming above the smoke pipe or if it just drips from the smoke pipe to the ash clean out.

Is this normal? I am i doing anything wrong? Any advise would be greatly appreciated.

Also, my cord wood is seasoned. I have tested with a moisture meter and its always between 15 and 22.

Thanks in advance.
 
No, I wouldn't consider that normal. You might want to do a flue inspection of the whole thing - there could be a buildup happening up higher.

Is that inducer fan you're talking about, an extra one on the pipe and not the one built into the boiler? I am not sure why an extra one would be needed - and not sure why it would run all the time.
 
No, I wouldn't consider that normal. You might want to do a flue inspection of the whole thing - there could be a buildup happening up higher.

Is that inducer fan you're talking about, an extra one on the pipe and not the one built into the boiler? I am not sure why an extra one would be needed - and not sure why it would run all the time.

Thanks for the reply. Prior to starting up the boiler I had the glue swept. So I don’t think there is a block. But it’s a good thought, I will call the chimney company and inquire.

The inducer is seperate from the boiler fan. It’s attached to the smoke pipe. It’s on a switch that controls the fan from high to low. The previous owner told me to keep it on low all the time and raise it up when opening the load door so smoke doesn’t spill out. I ran the boiler once without the fan on and a lot of smoke began spilling out of the boiler while all the doors were shut.
 
So this is a masonry chimney on the outside of the house from the ground up? What size is the flue for the Tarm?
 
So this is a masonry chimney on the outside of the house from the ground up? What size is the flue for the Tarm?

Yes masonry chimney on an exterior wall. My house is a two story colonial. The chimney starts in the basement and goes all the way up so it’s like 3 stories high.

I’m not sure of the flue size. It’s the same size as the flue for the fireplace and these flues are bigger than the flue for the oil boiler if that is helpful.

I am also wondering if the puddling in the ash box is coming from the ground rather than the tarm. When looking up the ash clean out under the tarm flue I see a few drips of condensation after a cycle but nothing to suggest a puddle in the ash box. But on the other hand cycle after cycle might be able to produce such a puddle so I’m not sure.
 
I am thinking the extra inducing fan was put in as a bandaid for the extra poor performing chimney. An insulated liner would likely improve everything.
 
I am thinking the extra inducing fan was put in as a bandaid for the extra poor performing chimney. An insulated liner would likely improve everything.

Yes that’s a good suggestion. The instruction book does say that condensation happens and suggests to line the chimney with a metal liner. And an insulated one would probably work best here.

The chimney is a really nice chimney, very well built. But maybe with it being on an exterior wall combined with the on an off of the tarm is creating an issue. It’s really frustrating though.
 
If the flue is on the larger size that is likely the main problem. Gasses would slow to a crawl when they hit it and be well below condensing point before they get out. But at least the larger it is the easier it would be to get an insulated liner down.
 
If the flue is on the larger size that is likely the main problem. Gasses would slow to a crawl when they hit it and be well below condensing point before they get out. But at least the larger it is the easier it would be to get an insulated liner down.

The flue is definitely bigger than the flue for the oil boiler. I think I will have a chimney person take a look at this. I am not familiar, what types of tradesman is the best to look for to determine problems with chimney performance?
 
Things are different on each side of the border. I think you want a chimney sweep.

Should also dig out the manual for your boiler & see what it specifically says about chimney requirements. It might be a bit vague though.
 
What you have is a cold chimney that never warms enough to draw well and a flue tile that is too large for the amount of flow. Flue must be sized to the appliance it is serving ie fireplace flue is usually large because the incoming opening is large. The Tarm flow is minimal.