water temp

I have a efm coal stoker and I;m starting to notice that sometimes usually in the morning the temp goes anywhere from 220 to 250. I have it set to go on at 180 an off at about 195. I watch it during the day when I'm around and it seems to be working perfect, just seems to happen over nite. any answers?

Are you using both returns in the bottom of the boiler?

Reasons for Using Both Return Lines and Bypass Line

Your boiler should stop maintenance stoking whenever it reaches 180 or when the thermostat setting is reached, and then it might climb another 30-40 degrees. If you leave your high limit at 195, and the water temperature is above that, the stoker motor will not come on until the temperature is below 195 which will result in outfires in the warmer months.

Do you turn back the thermostat in the house at night ? Maybe long idle overshoot? (I'm no expert)

readjust your aquatsat: set the high limit to 180, set the low to 130, differential to 15 and see how it goes. What happens is the boiler is stoking coal into the pot full blast up to 195 degrees when it shuts off, then it simmers in there at night when nobody is using hot water or opening the front door and can shoot up quite a bit. Make sure you don't have the high and low too close together or you will pull your hair out trying to figure it out. 130/180 should be just about perfect.

Do you have a draft regulator?

Glenn

Do you have your thermostat wired to turn the stoker on when it calls for heat. I did at first and over fired so I disconnected the TT inside the aquastat and let it run on boiler demand alone. What was happening was the boiler would get to temp and then A zone would call for heat and raise the temp more and more. Has no problem maintaining temp like this, much better without thermostat turning on stoker

kevin12973 wrote:Do you have your thermostat wired to turn the stoker on when it calls for heat. I did at first and over fired so I disconnected the TT inside the aquastat and let it run on boiler demand alone. What was happening was the boiler would get to temp and then A zone would call for heat and raise the temp more and more. Has no problem maintaining temp like this, much better without thermostat turning on stoker

Thats all well and good to do it that way if you are returning a low volume of water from your heating units,but if you have castiron radiators that return a lot of water back to the boiler, its better to have the boiler start stoking so it can keep up in stead of trying to recover from a lower boiler temp.


RY

Yea, no cast iron rads here so I am not familure with that configuraton. I do have alot of radiant heat that runs 130 going in, dont know how cold it is going back. Im sure not as relevent as cast rads. I do wish I had a few in a few locations around the house. Scraped a bunch about 10 years ago Mabey Just turn down the high to 190 and run in the160 to 175 range. Thats been working for me.