I would rather store excess heat in the boiler than just dumping it to a zone. Assuming the expansion tank is large enough, I would raise the dump zone setpoint and fail-safe high limit to 220 degrees (but that's just me
). You may also want to try reducing the operating temperature of your boiler...if you can heat the house with 160 degree water there is no need to run the boiler at 180 all the time. I'm running my EFM at 150 degrees...longer circulation times, less pipe expansion noise, and a cooler basement is the goal.
For me it's like this
Boiler Control Settings
Make sure the HI limit aqua stat is set to 190? degrees (N/C) of L4006A this shuts down the blower and is the high safety limit
Is the operating aqua stat set to 150? degrees. HI side (N/C) of L4081B this is low.
Is the operating aqua stat set to 200? degrees LO side (N/O) of L4081B this is the DUMP ZONE.
Thanks Guys I'm going to bump the dump to 210, I do have two expansion tanks a new 90 extrol and a old 30 extrol.
Do you know why the blower kicks on at 165 even if the setting is 150. Is it picking up -10 SV or is it -10 boiler temp?
Also seems the blower will run until the boiler water temp is 185. Not sure if it runs for x amount of time or +20 degrees?
Mark do you run your EFM between 150 and 170 now? I'm running it between 160-180 somewhere I read that it's the most efficient delta for heating water, maybe on this site or a link of this site.
Mark I have 3 hair handlers 1 in basement, 1 in second floor, 1 in attic. They all have a L4006A type control that is set to 140 to keep them from blowing cold air. The attic zone always seems to be cold, my psi is 18-22psi and i'm running 1 TACO 007 between the coal and propane and 3 tacos 007 (1 per zone). I don't know if it's an issue with the Lenox handler, bad circulation (been looking into variable speed delta T circulators). One of the problems is that if I keep the water at 160 and the temp drops 20 in the loop it gets to 140, so towards the end of the cycle when just idling at 160 the blower is not blowing so I was thinking running it 10+ between 170-190. I'm a noob at this so any feedback or comments are appreciated.