plumbing to the front of an EFM 520?
- Scottscoaled
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What are you talking about????? Not talking anything about gravity flow. Talking about colder return water coming into the bottom of the boiler, distributing all the way around the bottom of the boiler because it is colder(heavier) and rising as it gets heated. That is how every boiler that I know of works. It works the same from the front as from the back. When it is piped from the back, less water flows to the front because not as much heat transferred at the front. When it is piped from the front, more water flows to the back, before it rises. On the deal with the taps on the front being "mud legs"only, that isn't right either. The term mud legs, refers to steam boilers and the sediment created by steam causing corrosion and it settling in to the bottom of the boiler . You would want the cold water coming in the front if it was a steam boiler.
- Rob R.
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It will work better with the majority of the flow going through the area with the majority of the heat exchange surface area, but feel free to hook it up any way you like. Like I said earlier, it was my opinion.
My comment about converting a gravity system was in regards to the changes you need to make to balance the flow. When setup for gravity, the radiators at the top of the system require restrictions in the piping, since the hot water is lighter and wants to go to the top. As soon as you put a pump on it, the radiators closest to the pump get most of the flow, and the top floor gets cold. A boiler would be the same way, you put 10-12 gallons per minute through it and most of the water will take the shortest path. I am not sure how much of a difference it makes in the overall operation, but it seems to be enough that EFM doesn't bother to include an alternate piping diagram in their manual.
My comment about converting a gravity system was in regards to the changes you need to make to balance the flow. When setup for gravity, the radiators at the top of the system require restrictions in the piping, since the hot water is lighter and wants to go to the top. As soon as you put a pump on it, the radiators closest to the pump get most of the flow, and the top floor gets cold. A boiler would be the same way, you put 10-12 gallons per minute through it and most of the water will take the shortest path. I am not sure how much of a difference it makes in the overall operation, but it seems to be enough that EFM doesn't bother to include an alternate piping diagram in their manual.
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Who said anything about "mud legs"? I called them "flush plugs" because that's what they are called in the installation manual. The manual also plainly identifies the return tappings as being the ones on the back, and recommends that both be used, whether for hot water or steam. I don't see a rationale presented in the manual, but it is certainly consistent with Rob's earlier explanation.Scottscoaled wrote: ↑Wed. Feb. 28, 2018 8:50 pmWhat are you talking about????? Not talking anything about gravity flow. Talking about colder return water coming into the bottom of the boiler, distributing all the way around the bottom of the boiler because it is colder(heavier) and rising as it gets heated. That is how every boiler that I know of works. It works the same from the front as from the back. When it is piped from the back, less water flows to the front because not as much heat transferred at the front. When it is piped from the front, more water flows to the back, before it rises. On the deal with the taps on the front being "mud legs"only, that isn't right either. The term mud legs, refers to steam boilers and the sediment created by steam causing corrosion and it settling in to the bottom of the boiler . You would want the cold water coming in the front if it was a steam boiler.
Mike