New Weil Mclain EG 40 with near boiler pipe issues?

ttekushan_3

> that is a beautifully piped steam boiler . <BR>
> But it might be a little off-spec though . <BR>
> Like you said , 2 1/2 inch should have been the <BR>
> minimum on the header . Is this a counterflow <BR>
> system ? Are the steam mains pitched down towards <BR>
> the boiler ? If it is , the point where the new <BR>
> piping meets the old header should have been <BR>
> piped a little different . Are there any main <BR>
> vents at the ends ? <BR>
> <BR>
> I'm not sure how the <BR>
> undersize and counterflow piping will affect the <BR>
> overall performance . What might be the main <BR>
> issue is if the boiler is sized right . Did <BR>
> anyone measure up the radiators ? Can you tell us <BR>
> how many rads you have ? Are many of them big ? <BR>
<BR>

V8toilet

Weil Mclain EG40 near boiler pipe issues

I’ve recently got a new boiler installed and replaced my 80 year old snow man that still worked very well. Unfortunately the old boiler cost a little too much to run with an AFUE efficiency of about 50%. There are some pictures I posted here of the old boiler and of the new boiler and the piping job that was done on the new installation. Most of the piping looks good with the A-dimension from water line to the bottom of the header of 32 inches (manufacturer calls for a minimum of 24 inches) and the header and equalizer all seem to be right according to the manufacturers specifications.

Last year the old boiler heated the house flawlessly and all the radiators would get hot and heat the rooms evenly after I balanced them with all new venting of the proper sizes for each rooms/ radiators needs. I have a computerized Honeywell HT7400 thermostat, which learns run time and overshoot and automatically adjusts or learns your system and the old boiler worked awesome with this thermostat. I got each room within 3 degrees in the house after balancing the radiators. That’s pretty good for an eighty year old one pipe steam system even by today’s standards. The old system was a coal fired boiler retrofitted with a natural gas burner.

The new Boiler is a Weil McLain EG 40 with about 325 sq ft of radiation. Now the new boiler is running with the same equipment now and the thermostat has had time to adjust to the new boilers quicker steaming rate. Now the radiators furthest away don’t get hot or hardly hot at all before the thermostat is satisfied and the system is unbalanced compared to before. I tried balancing the radiators again but I think that if the new boiler is producing good dry steam like the old one did that nothing other than a faster system should have changed. I read the Weil McLain owners manual and checked the riser size and header size that I have compared to what Weil McLain says I should have as a minimum. What I have now is one two inch riser and the header is made up of just two inch pipe and the correct 1-1/2 inch equalizer. In the Weil McLain owners manual it says I should have a minimum of one 2-1/2” riser and 2-1/2 inch header. Now remember I have 8 more inches of rise or clearance between the water line and the bottom of the header than Weil McLain says I need for a minimum so that should help any water drawn up to separate from the steam I think. For the experts here could you please look at the before and after pictures and let me know If I should call the contractor and try and get them to change it to at least the 2-1/2” it should be? Do you think that if the riser and header were larger that I would get more even heat in the radiators and dryer steam? How do I know if I am getting wet or dry steam? I have no water hammer or spitting vents and I’ve skimmed the crap out of this thing. I’ve done just about everything I can do including taking a sample from the boiler and boiling it on my stove just to see if the water was foaming compared to a clean sample. I even called Weil McLain and they said I should have 2-1/2 inch pipe.

The old boiler had two, two inch risers as you can see in the picture; twice the volume of the new one!

Do you guys think the contractor should redo the riser and header in at least 2-1/2 inch or larger? The owner’s manual like I said before states a minimum of one 2-1/2” riser and header with 1-1/2” equalizer. Is 2 inch too small or can it work with a longer riser if 32 inches?

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rick_53

have you called the contractor back and spoke of the issues with the rooms.

Unknown

I have to say

that is a beautifully piped steam boiler .

But it might be a little off-spec though .

Like you said , 2 1/2 inch should have been the minimum on the header . Is this a counterflow system ? Are the steam mains pitched down towards the boiler ? If it is , the point where the new piping meets the old header should have been piped a little different . Are there any main vents at the ends ?

I'm not sure how the undersize and counterflow piping will affect the overall performance . What might be the main issue is if the boiler is sized right . Did anyone measure up the radiators ? Can you tell us how many rads you have ? Are many of them big ?

ttekushan_3

What Ron Jr. said and

that counterflow systems are sensitive to pipe pitch and steam velocity. Once the 2" transitions to the original piping size and arrangment everything's the same as it was including the tappings at the bottom of the mains to intercept return water. So what's different?

1) Could any of the mains' pitch have been changed?
2) Is the smaller riser carrying over entrained water into the system, and while the system is quiet for short durations, does it suddenly misbehave if it has to run for a longer period of time? The point is, does the system bang hiss or spit if it runs long enough to get the cold radiators warm?
3) What kind of vents do the radiators have? The vent proportions may be correct for the old slower steamer, but the vent rate may not be correct for the output steam volume of the new boiler.
4) Where is the pressure set?
5) Did you take your boiler water sample from a skim tap? The impurities that cause water line problems are on surface of the water.
6) Is the missing insulation on the near boiler piping causing a pulsing steam flow (or even an alternating pulsating flow between the two mains)? If so, it can delay the advance of steam from 10 minutes to ∞ depending on local conditions.
7) And then there's the dreaded combination effect. You know, the one where impure entrained water from the smallish riser carries over into system piping into a main whose pitch has been changed a bit being pushed and pulled up the main into an area that forms a sort of stationary front, moving fore and aft going nowhere because of the cyclical vacuum being created by the uninsulated near boiler piping. Ah. Do the vents on the cool radiator "pant?"

Just more things to consider to keep up the level of confusion. Seriously, though, I'm interested to see what your actual EDR is and what solves the problem in the end.
-Terry

V8toilet

Ron,

This is a counter flow one pipe steam system so yes the mains pitch towards the boiler and there is a condensate return pipe just before the header on each main. There is no old header on this installation. The riser, equalizer, and header are all new. How should it have been piped? There are no main vents as of yet (going to install those next). They did measure all 9 of my radiators to correctly size the boiler.

Ttekushan,

They didn’t change any of the old main pipes pitch except for a short section where they increased the pitch to about one inch in four feet on a 6 foot section because it was hanging after the old one was taken out. If the system does run until all the radiators get hot (it has) it does not hammer and there is no spitting of the vents or any other abnormalities. The only difference is that the radiators don’t all heat as quickly after the point the boiler starts steaming even thought the old one took twenty minutes to get to a boil from a cold start and the new one takes just 8 minutes. I took my boiler sample from the top as I skimmed the boiler where it counts. I also forgot to tell you guys that the pipes you see uninsulated in the picture are actually insulated now. I took that picture before I insulated them with 1” fiberglass. I don’t think the vents are pulsing and when the boiler is steaming and the water level bounces normally like the old one did. I can check for pulsing air with a smoking match next time the system is running. The vents are Matco Norca adjustable 180 and I have one Maid O Mist #6 on the furthest radiator from the boiler. Most of the adjustable vents are ¾ to full open especially the ones furthest away. Like I said before though with the old boiler these same vents worked fine and they are less than a year old. I’m going to recheck my EDR again and make sure it matches the boiler. The 1.33 pickup factor is already factored into Weil McLains boiler EDR ratings so I don’t have to calculate it separately.

Please see the picture of the insulated pipes I attached.

Thanks guys for the input.

V8toilet

OK I measured my Radiation and I have 276 sq ft. Weil McLain's next smaller model is a EG 35 with 258 sq ft and mine is a EG 40 with 325 so it is correct.

Steamhead (in transit)

I think you'll have to get it repiped

if W-M says to use 2-1/2-inch or larger, that's what it should be. You can go larger, but NOT smaller!

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