mmeck wrote:Hello All
I bought a house a couple years ago with and EFM stoker in Northeastern Pa (right in coal country). It worked like a charm until just recently. For some reason the fire wants to go out. I found out the only time it kicks on is when triggered by the thermostat. I understand there is a timer that is supposed to periodically turn it on at a specified time. The brand of timer I currently have is Will-Burt. How often is this feature supposed to turn the stoker on? I am thinking that is my issue considering it will not fire at all until the thermostat drops below temp. Any ideas?
Your efm stoker steam unit will maintain a minimum water temperature by control of the L4006 aquastat. It's set to maintain a temperature for household hot water. When the boiler temperature falls below this limit, the aquastat will tell the stoker to start up and bring it back up to the minimum temperature. In the summertime, your timer will force the stoker to run every half hour to accomplish the same thing.
The other way for the stoker to start up is by the thermostat. On a call for heat, 24V will go from the tstat to the timer relay and cause 110V to flow to a low water cutoff, if you have one, or to the pressuretrol and then to the stoker motor. The pressuretrol is a NC, normally closed contact and will open, shutting off power to the stoker, when the pressure is above the set point, usually 1 1/2#.
Check your water level after the stoker has been at rest for a moderate period of time, NOT when it’s running or shortly thereafter. The circulator must also be OFF. The water level should be high enough at rest to cover the hot water coil. This would be 46 ½” measured from the bottom of the base.
Some other info about your steam boiler: If you are getting banging in the pipes, one reason is dirty water, causing wet steam. On the efm boiler, you can skim the water through the water glass port. Skim several times until it’s clean. You can also add an emulsifier to the water to dissolve any oils, which will then fall to the bottom of the boiler.
Periodically, open the drain to drain a small amount of water/sediment out of the bottom of the boiler.
Banging can also be caused by firing too high, causing the water to come to a boil too quickly and improperly pitched pipes, especially near a radiator that has settled.