Hi Wolverine, what do you mean by firebox temp, and jacket temp??
Water temp is really what we are concerned about,, I'm assuming you mean water jacket temperature? The actual water temp thea the aquastat controlls ?
The firebox temp may be as high as 1000* when the fire is really cooking,,
Greg L
Keystoker KAA-2 Control/Set-Up
Yes, when I referred to firebox temp I was reading the temp through the draft porthole in the door over the fire. I did not attempt to read a temp at full fire, I don't think my probe could read that high. I was tring to get a feel for the minimum fire bed required to keep the jacket at just above the aquastat temp to start (160)
Ok, It's been a couple of months since the boiler was installed and I have experienced a couple of problems with the longer duration of cold weather. First with sunny days the solar gain to the house was enough to cause the fire to die down to a stand-by size, but as the sun set and the temp dropped ( mid teens) I found the unit struggled to hold room temp in the mid to lower 60's. Also if temp. outside dropped to near 0 the boiler could not keep up at all, since the house is set up with 2 zones I found that if 1 zone had no demand the boiler could recover, short term this was what I did until I was able to put some time into evaluating what was going on. The previous connection was to maintain a jacket temperture, so the boiler had a lag on the low side and an over shoot on the high side. once the boiler got behind the circulator would shut down to let the boiler catch up and I would lose room temp, the greater the demand the more significant the loss. Please keep in mind that I am attempting to keep two boilers connected paralel and the primary is coal but the oil burner is disabled.
What I have done in the past 2 weeks has seemed to correct those issues. I have a Taco 502 2 zone switching relay box, that each zone from the room thermostats connect to, these drive the circulator pumps independently to meet heating demand in the living areas, the circulator between the boilers is connected to the circulator output on the coal aquastat. The Taco relay control also gives me a common output that I was able to connect to the TT terminal on the aquastat, I added a selector switch to send this output to either the coal or oil aquastat and this gives me the signal to the "burner" selected to start. This now seems to allow the aquastat to run between the limits as the mfg's literature specifies, with a demand there is little lag and the overshoot is also greatly reduced. So with the onset of such cold weather I have upped the jacket temp to run at 190 Hi. Last thing that I have completed is for the DHW coil, I connected them in series to go through the coal boiler then pass through the oil boiler before going through a mixing or anti-scald valve. This seems to have a balancing effect during periods of hi demand .The connection of the DHW circuit included an isolation and by-pass loop for service or operation selection.
Currently, I have the settings on the coal boiler at 190 HI 170 LO, selector switch is set to Coal. The Oil boiler is set at 160 HI 140 LO and the burner has been enabled. The only time that I have heard the oil fire up was during a frigid windstorm that came through last week (20-30 mph gusts 1degree actual temp. don't even want to know wind chill) and that was during early A.M. and seem only to be a minor boost and the coal burner was able to recover and keep up since.
And finally my friend, Coldwind passed away suddenly Nov. 28 .We worked together and he was an avid reader of this forum. We had some great discussions about any form of alternative energy. He was 47, and I'm really gonna miss Bob.
What I have done in the past 2 weeks has seemed to correct those issues. I have a Taco 502 2 zone switching relay box, that each zone from the room thermostats connect to, these drive the circulator pumps independently to meet heating demand in the living areas, the circulator between the boilers is connected to the circulator output on the coal aquastat. The Taco relay control also gives me a common output that I was able to connect to the TT terminal on the aquastat, I added a selector switch to send this output to either the coal or oil aquastat and this gives me the signal to the "burner" selected to start. This now seems to allow the aquastat to run between the limits as the mfg's literature specifies, with a demand there is little lag and the overshoot is also greatly reduced. So with the onset of such cold weather I have upped the jacket temp to run at 190 Hi. Last thing that I have completed is for the DHW coil, I connected them in series to go through the coal boiler then pass through the oil boiler before going through a mixing or anti-scald valve. This seems to have a balancing effect during periods of hi demand .The connection of the DHW circuit included an isolation and by-pass loop for service or operation selection.
Currently, I have the settings on the coal boiler at 190 HI 170 LO, selector switch is set to Coal. The Oil boiler is set at 160 HI 140 LO and the burner has been enabled. The only time that I have heard the oil fire up was during a frigid windstorm that came through last week (20-30 mph gusts 1degree actual temp. don't even want to know wind chill) and that was during early A.M. and seem only to be a minor boost and the coal burner was able to recover and keep up since.
And finally my friend, Coldwind passed away suddenly Nov. 28 .We worked together and he was an avid reader of this forum. We had some great discussions about any form of alternative energy. He was 47, and I'm really gonna miss Bob.