Summer has arrived in Maine at long last. Temperatures have risen into the 80’s and all is well, but the pellet boilers need to be “summerized.”
As temperature differences between my basement and the outside air have converged, I’ve begun living with a continuous “low chimney flow” condition and the associated red indicator light on my Janfire NH pellet burner. I have cleaned the breach of the boiler and the flue pipe, and I always keep the boiler free of excess ash. I have the boiler on an independent chimney, which, as our technician puts it, “would suck your hat off.” The chimney rises well above the house. (June 1, Alas, the “low chimney flow” error was a legitimate problem, my baffles had fallen over the burner bowl. Realignment of the baffles resolved the low chimney flow condition. The baffles tend to “gain weight” as combustion by-products adhere to them; they are scheduled for redesign by Bosch.)
To confirm that the light was indicating an actual overheat condition at the drop shaft sensor, I checked the setting. Its default is 158 degrees, or so, and, sure enough, the sensor was reporting 156, 157 degree temps as the boiler was running at low fire. I advanced the temperature 8 degrees to see if I could eliminate the fault light, but I couldn’t; the light continues to indicate a high temperature at the dropshaft sensor from time to time. There are no negative impacts of this situation on my boiler’s performance; it makes all the hot water we need, spending most of its time in “keep alive” or shut down.
As the summer demand for heat changes to domestic hot water, only, systems with very little heat loss in the piping might need to have their minimum boiler temperatures reduced to avoid unnecessarily high boiler temps. In my own case, about 60′ of 1 1/4″ copper tubing leading to and from my oil system “wastes” heat into the basement eliminating any such need. In the winter, I appreciate that extra pellet heat in the basement; now, I’m likely to put insulation around the pipes to keep it out of the basement.
Dutch is a Director of Maine Energy Systems in Bethel, Maine.