RickH said:
When the house is caling for heat the boiler runs wide open and struggles to maintain 150 degree water. I would think it should be able to cycle if it was large enough or at least maintain a higher temp. The entire stove was cleaned out about 1 month ago with the normal ash buildup. I should clarify that when installed new last year it struggled to maintain the heat and would run constantly. Filling it 5 plus times a day on a mild day is not practical or efficient. Thanks for the input.
I agree, Rick. The fact that it's running wide open and can't hold steady temp tells us that the pumps and piping are moving all the heat produced plus some. So the problem is not air bubbles, weak pump, or small lines. I think we're down to three scenarios: 1) boiler is operating inefficiently 2) heat is being lost somewhere 3) boiler truly is undersized for the application. Here's some thoughts:
1) BOILER NOT OPEARATING EFFICIENTLY - based on enerything you've said, you got good wood and fairly reasonably clean tubes, this does not seem to be the problem. Could the rear tubes badly fouled? Have you checked them?
2) HEAT IS BEING LOST SOMEWHERE: I suggest that you trace the whole boiler loop to gather current water temperature data while under full fire for
a) leaving the boiler
b) into house
c) into forced air hx
d) out of hx
e) into/out of backup boiler (if it applies)
f) leaving house
g) return at boiler
I think this is important to so you know exactly where all the heat is being given up. Maybe there's more water in the ground since you measured it last and you're losing more heat there?
3) BOILER IS TRULY UNDERSIZED
a) do you have a backup fossil fuel boiler? Do you have any data on avg btu/hr? Or can you let the house run off of it long enough to calculate some heat consumption (ie 100,000 btu/hr boiler runs 45min/hr is roughly 75,000btu/hr )
b) do you have a calulated heat loss for the building?
c) IF everything is working right, I think the boiler will probably deliver about 60,000, maybe 70,000 btu/hr max to the house. How does that compare with a) and b)?
my 2 cents