Weil-McLain EGH ratings lowered

Dave in QCA

I just wanted to call everyone's attention to the fact that the EGH series atmospheric boiler by Weil-McLain has had all of the ratings lowered. For example, the EGH-85 used to fire at 349,000 BTU and now if fires at 315,000 BTU. There has also been the addition of baffle plates that slide in between the sections. It appears that the combination of adding the baffle plates and lowering the firing rate by roughly 10% results in a higher efficiency. It no doubt will result in a longer life for these boilers too.





Of note is the fact that the old numbers are still on the "Specifications tab" on the first link for the EGH boiler. However, the new correct numbers are in both the Sales Brochure and the Installation Manual.



I called WM technical service to point out that they have conflicting information on their website. It is supposed to be corrected soon.

Rod

Adding Baffles to a Pin Boiler?

Hi Dave- As far as longevity is concerned, I'm wondering whether the baffle plates are all that good of an idea on a pin boiler. Would this greatly increase the temperature of the casting above the waterline?  I was thinking about this the other day when MarkS mentioned that he had installed "T" baffles in his boiler. (See the attached brochure and patent which Chris J found)   Thoughts?

-Rod

Dave in QCA

Lacking Information

Rod, you make some very good points. However, as far as Weil-McLain EGH series, there is not discusion or information that I have been able to find that talks about the new baffles. In fact, I found another place in their documentation that has not yet been updated, and that is the EG installation manual which also covers the EGH commercial range. That portion is out of date now.



My assumptions, and I may be foolishly optimistic, are that they improved both efficiency and longevity by combing the two changes. First, they reduced the firing rate by 10%. Then, because down firing an atmospheric boiler tends to increase the excess air and reduce the efficiency, they installed baffle plates to slow down the flue gasses rising between the sections. It seems to me that this would have the effect of keeping the temperature of the flue gases high at the lower portion of the passage and reducing the temperature of the flue gasses at the upper portions of the passage, because of course, because the speed of the flue gasses would have been reduced. But... this could all be wishful thinking on my part.



I am quite interested in ECR/Utica modifying their sections to specifically address poor water corrosion, and while they don't say so, they are talking about rotting at or slightly above the water line, as we commonly see. Very interesting that the boiler shown in the attachments you posted, has no pins above the water line. In addition, they are adding baffles that appear to create a barrier between the flue gasses and the portion of the cast iron section that is above the water line. VERY interesting. That brings up the topic of the Burnham Megasteam. What I find interesting about this boiler is not its very high efficiency and its 3 pass design, but that 100% of its heat transfer surface is below the water line. And... they warrant it against corrosion. I makes one wonder why all boilers are not designed this way!



H. B. Smith had a commercial atmospheric that they have discontinued, but the interesting thing about the sections on that boiler is that there were NO pins above the water line at all.



Hopefully there will be more information coming regarding the changes on the WM EGH series.

Rod

Pin Boilers

Hi Dave - I brought this subject up as I thought you might be considering retro fitting your boiler with the baffles. The increased efficiency is nice though one hope’s Weil McLain has also considered any possible downside to the changes. If the baffles are only installed between the pins below the waterline, what this does temperature wise to the pin area above the waterline I have no idea.

     I too noticed the Utica SF doesn’t have any pins above the waterline. The I&O manual doesn’t show that model boiler block as a dual use (steam & water) so unless the block shows up somewhere else in the company’s boiler line, it seems dedicated to steam only. That makes one wonder about the dual use boiler blocks that do have pins above the waterline. Is using that type of boiler for steam detrimental to the overall longevity of the boiler?



   On the Megasteam - If I was Burnham, I’d give MarkS a free Megasteam block to play with. One of the rumors that was floating around as to why Burnham  wasn’t offering the Megasteam with a gas option  was that the efficiency numbers were lower with gas power burner.  It would be very interesting to see what a Megasteam  with the Midco burner would do.

- Rod

Dave in QCA

Reply

Rod, I agree completely. I may have been part of the converation on Megasteam efficiency. On oil, it is high enough to get the Magic Energy Star rating. On gas, it most likely would not. I think that is the krux of it. But, I still don't see why they don't just give it another name. Or... The could go back to the drawing board on the Independence and figure out how to make an atmospheric where there is not heating surface above the water line. I'm sure it can be done. Hell. of course it can. I just imagined it in my mind.



No, not planning on putting baffles in my WM 680. I'm getting pretty good performance and reduced the consumption when compared to the old ECR/Pennco by 30%. I'm happy about that!

JStar

Baffles

We rip out a lot of 60 year old boilers with bricks in the flue baffles above the water line. Maybe 60 years isn't long to satisfy every consumer, but that's a long enough life for me.



With such a small amount of space inside all of these residential boilers, the temperautres really won't change that much to cause stress by adding baffles. In fact, every time an oil boiler gets dirty/restricted, it effectively adds its own "baffles" and traps heat in the boiler. As long as the combustion numbers are in line, it can do a lot to raise efficiency. Every system, and every boiler is different and needs to be field tested. They will need to provide an easy method of removing or adding these baffles.

ChrisJ

Baffles

I found a bunch of cast iron baffles from an old 3 pass boiler in one of my crawl spaces.

Dave in QCA

new design

Utica has redesigned the heat exchanger. See the files that Rod attached. The Patent application clearly shows the pins stopping at the water level and additionally, there is a shield that slips over that upper part of the section that has no pins.

butlermog

EGH-85

Dave and Rod (or anyone else),

Could you please tell me what these changes to the EGH-85 mean for me - a homeowner with an EGH-85.

Are there things that I could/should be doing now that WM has made these changes?



Secondly, and this could be a separate topic if it needs to be: I have seen a few posts here that talk about "downfiring" a gas boiler, or "lowering the firing rate" (specifically Gerry Gill said the following in 2004 about Mouat systems: "by the way, with mouats you need to downfire the gas...mouats boiler simmered"). Is "downfiring" a result of modifying the amount of fuel getting to the burners? And if so, how is that accomplished on a boiler like the EGH-85?

Dave in QCA

Pre-Change EGH-85

What it means for you as a homeowner is that you own and EGH-85 that came out of the factory before it was redesigned. While we know that there are 2 changes, lowering of the firing rate and the addition of baffles, there may be other changes to the design of the block and the combustion chamber that we do not know about.



Since we do not know what all of the changes are, it would be unwise to attempt to make field changes to your boiler unless those were approved by Weil-McLain in writing.



As for lowering the firing rate, it can be done by changing the orifice in each burner or slightly lowering the pressure to the manifold. I would not recommend either of these unless you determine that your boiler is oversized. Also, while lowering your firing rate by 10% might not have an effect on the efficiency, lowering more on an atmospheric boiler often has the effect of significant drops in efficiency. The reason is, in an atmospheric set up, you can regulate the primary air to each burner so it is burning at optimum mix, but the secondary air, that being the air that comes in around the burner flame and mixes with it in the combustion area, cannot be controlled. If you reduce the size of the fire, the proportion of the fuel fire / air mixture changes and it takes engineering, not adjustment, to balance it. On a power burner, you have the ability to tune the total air and thus can tune in efficiency at whatever rate you decide to fire at.



So, as an owner of an old version of the EGH-85, the fact that the new ones coming out of the factory are different means nothing for you.