I started losing efficiency a day or two ago (thankfully just post the back to back -17 and -8 degree nights) , so I spoke with Darren at AHS and he pointed me right to the issue. There is an approximately 1.5" x 2" channel that runs from the inside wall of the cyclonic separator across and into to the main swirl chamber of the boiler. As this channel gets plugged up it causes a sudden loss of efficiency and it also causes the sight tube (flapper) cover to not get strongly pulled in when the fan comes on. I had this happening also all at once in conjunction with losing efficiency.
Last night I emptied out the coal hopper and I woke up this morning to a cold boiler. Let me be clear that you can't see this channel if you do not remove the cyclonic separator tube, as it is behind it. I pulled the cyclonic separator out and worked (OK, forced, it took some effort) a boiler brush through the channel from the cyclonic separator end until it finally broke on through to the swirl chamber (at which time the brush head was in the channel by what felt like nearly a foot, and then it suddenly fell on through into the large swirl chamber indicating success). I worked the brush to clean this area, and I cleaned the cyclonic separator area (which otherwise was pretty clean), and I also cleaned the flue pipes and the baro damper while everything was out.
Got it all back together and as soon as the fan was initiated the sight tube cover slammed closed with good force. This was the first indication of success. Loaded it with some ash (2 scoops) and with roughly 320 lbs. of coal, and repeated the flapper cover closing test successfully. The sight tube cover slammed shut immediately. Darren at AHS had led me right to the problem area. Needless to say I'm in my 3rd winter season and until I spoke with Darren I didn't know that this all important channel was there at all, so despite cleaning the swirl chamber and the cyclonic separator and the flue pipes I had never before cleaned this all important channel. Now it will be a part of every cleaning. I also greased the pillow block bearings for the fan and oiled the chain and bearings for the ashing motor.
When I do my summer cleaning I will pull the back side apart for a full and major cleaning and clean the swirl chamber proper. I will also clean the formerly missed channel, etc.. from, now on.
Presently firing back up and so far all is going quite well. Lesson learned. Thank you Daren Bricker!
Last edited by lsayre
on Sat Feb 01, 2014 11:13 am, edited 3 times in total.