I called Fred Seton today, and asked his thoughts on why my boiler is kettling and he told me the problem is not what he would call kettling. he basically told me the problem was too much flow thru the HX ? he told me the excess flow was causing all the banging, thumping and boiling sounds, even tho as soon as the fire dies down the noise goes away? However, 5 minutes after I hung up, he called back and said he thought the problem was that the flow was too fast only thru the middle water tubes, and that water was not going thru the outside tubes and that was causing the kettling. LOL
here are a few other things he said about the Seton boilers.
1) Seton boilers are capable of reaching 200%+ efficiency on a long hot burn. According to Fred, the Seton 180 (180K btu) can reach up to 500K btu output ! Very impressive don't you think !
2) Seton boilers are "made to idle"
3) Seton boilers are more efficient the LONGER they idle
4) Seton boilers reach firebox temps of almost 3K degrees (even tho the Kaowool on the inside is only rated for 2300 degrees)
4) Seton boilers never develop any creosote on the water tubes, even with long periods of idling, because once the unit re-fires the super high combustion temps just burn up any creosote leaving the water tubes nice and clean
Now, personally I disagree with every one of those claims.
According to Fred, most of his boilers run either 1" or sometimes 3/4" line with average distances of 100' or more one way. the longer the distance, the bigger the pump he recommends, with a Taco 0011 about as big as he would use. for shorter runs he would use something like a Taco 008. Now according to Fred, even with a long run and a system head of 10-15 feet, a Taco 0011 should be pushing about 20 GPM thru the HX and he says the HX delta T would be about 15 degrees, 25 degrees maximum. So when I told him about my system, with way less than 10 feet of head, why am I getting a delta T of 25-30 degrees, with the circulator on high, and a lot of banging during the process, he said it was because the flow was too fast ! According to the pump curve for a Grundfos 26-99 on high speed, i should be pumping enough water to fill a 55 gallon barrel every 2 minutes ! Thats more water than my well pump will move, and in no way would result in a delta T of 30 degrees in the HX unless perhaps my flu temps were 1000 degrees or more ! he suggested I go with a smaller pump. I told him that would result in an even greater delta T and much more idling. he said thats good, the longer it idles the more efficient it is !! i kid you not, thats what he said.
he said even if one or more of the water tubes in the HX were plugged up somewhat, it would not cause any kettling, even tho he did admit that too low of flow in the HX could in fact cause kettling.
Well, I will humbly admit I have no clue what is causing the kettling, and I think its clear that Fred doesn't have a clue either. The one thing I do know is that I'm taking the HX out next spring to see if anything is plugged or corroded. That is the only way i can eliminate that as not being the problem. But for whatever reason, the problem as I see it is that the heat is not being removed from the HX fast enough.
Pat
here are a few other things he said about the Seton boilers.
1) Seton boilers are capable of reaching 200%+ efficiency on a long hot burn. According to Fred, the Seton 180 (180K btu) can reach up to 500K btu output ! Very impressive don't you think !
2) Seton boilers are "made to idle"
3) Seton boilers are more efficient the LONGER they idle
4) Seton boilers reach firebox temps of almost 3K degrees (even tho the Kaowool on the inside is only rated for 2300 degrees)
4) Seton boilers never develop any creosote on the water tubes, even with long periods of idling, because once the unit re-fires the super high combustion temps just burn up any creosote leaving the water tubes nice and clean
Now, personally I disagree with every one of those claims.
According to Fred, most of his boilers run either 1" or sometimes 3/4" line with average distances of 100' or more one way. the longer the distance, the bigger the pump he recommends, with a Taco 0011 about as big as he would use. for shorter runs he would use something like a Taco 008. Now according to Fred, even with a long run and a system head of 10-15 feet, a Taco 0011 should be pushing about 20 GPM thru the HX and he says the HX delta T would be about 15 degrees, 25 degrees maximum. So when I told him about my system, with way less than 10 feet of head, why am I getting a delta T of 25-30 degrees, with the circulator on high, and a lot of banging during the process, he said it was because the flow was too fast ! According to the pump curve for a Grundfos 26-99 on high speed, i should be pumping enough water to fill a 55 gallon barrel every 2 minutes ! Thats more water than my well pump will move, and in no way would result in a delta T of 30 degrees in the HX unless perhaps my flu temps were 1000 degrees or more ! he suggested I go with a smaller pump. I told him that would result in an even greater delta T and much more idling. he said thats good, the longer it idles the more efficient it is !! i kid you not, thats what he said.
he said even if one or more of the water tubes in the HX were plugged up somewhat, it would not cause any kettling, even tho he did admit that too low of flow in the HX could in fact cause kettling.
Well, I will humbly admit I have no clue what is causing the kettling, and I think its clear that Fred doesn't have a clue either. The one thing I do know is that I'm taking the HX out next spring to see if anything is plugged or corroded. That is the only way i can eliminate that as not being the problem. But for whatever reason, the problem as I see it is that the heat is not being removed from the HX fast enough.
Pat
