New boiler install Weil McLain EGH-85 (issues)

ATM

The original 1920s coal steam boiler as well as a gas boiler (360,000 btu) that was added sometime in the mid-1960s came out (along with the asbestos) and a new Weil McClain EGH-85 put in the coal boiler's space. The original system I believe is a two pipe Duhnam Vapor System located in Southwestern OH. Pictures





New boiler and piping


2 Hoffman 75 vents


Radiators begin to heat fairly quickly (about 15-20) minutes on a cold start and evenly throughout the house but I have to have the Vaporstat up to 5-6 ounces so that it doesn't shut off before steam gets to all of them. No banging or noises, not that there was previously.

Two issues I'm having since the install finished last Friday. One, the boiler is is short cycling on pressure. I had to increase the Main setting on the Vaporstat to 5oz. and that seems to get heat to all 17 or 18 of the radiators okay before shutting off on pressure. However the Hoffman vents make a lot of hissing during the initial burn cycle.

There is a single main line (2 or 2.5 inch) around the perimeter of the basement that feeds all the radiators. The house is about 3700 sq ft. and the installer calculated the EDR for all of the radiators at about 800 or 900 I believe. The EGH-85 was the smallest boiler in all the estimates we got but the others were for the EGH-95 or equivalent of the previous gas boiler. Some didn't even bother figuring out the EDR of the system.

Once it shuts the Hoffman vents immediately begin hissing again and letting in air and the boiler re-fires within one minute. The only way to slow that time is to set the differential very close to or at 5 oz. or more. I assume that means that the time for the system to allow the pressure to drop from 5oz. to close to 0 ounces is also less than a minute.

The second issue is that the water auto feeder has added water each time the boiler has been run. The boiler was skimmed two days ago and water bounce in the sight glass is now minimal.

I have a couple calls out to the installer and the boiler rep but thought I'd see what advice people have here. From what I've read my thought is to replace the Hoffman vents with 4 Gorton #2s to see if that helps the pressure shutoff issue.

Other questions; Is it worthwhile to shut off or cut back radiators in rooms that aren't used? Does doing so contribute to the short cycling? Currently only about 30% of the house is used regularly (not including the basement which is) but I'm not sure if turning them off will cut gas usage all that much. The installer said that re-insulating the mains (used to be covered in asbestos) wouldn't be worthwhile other than keep people from getting burned. Everything I read in Dan Holohan's books suggest otherwise, so we are getting estimates on doing so.

Fred

You need to make sure you have enough venting on the mains to push all the air out as quickly as possible. Your Vaporstat should be set to cut in somewhere around 4 oz and cut out at about 12 oz. Closing radiators will only make the boiler oversized and will add to your problem with short cycling and Yes, all the mains and header should be insulated to minimize steam condensation before that steam get to the radiators. You can get a ebook on this site by Gerry gill, titled "Balancing Steam Systems using a vent Capacity Chart" to calculate how much main venting you need, based on pipe length and diameter. Worth its weight in gold! It costs only $10.00 and is immediately downloadable. As to the water feeder adding water, does the boiler overfill or does it just come back up to a normal water level? If it overfills, it is possible that the condensate return is slow or the probe for the feeder is not working properly or is in the wrong boiler tapping. It is also possible that the boiler needs more cleaning/skimming. If the water level just returns to the normal level, water is leaking somewhere. Are there any buried returns that may be leaking?

SWEI

Please tell me you still have that gorgeous Dunham gauge somewhere...

ATM

Nope, the asbestos removal firm took it. Only have the doors left.

KC_Jones

SWEI said:

Please tell me you still have that gorgeous Dunham gauge somewhere...

I was thinking the same thing, but my thought was ...I would love to have that. The asbestos firm probably put it on ebay and made a mint.

Dave0176

I know the manual only calls for two 2" risers and a 3" header, but if it were me, I would run two 3" risers and a minimum of a 4" header maybe even a 5" header. Also it'd be a drop header.

With two 2" risers your steam velocity is 46.8 fps, if you had two 3" risers it cuts velocity to 21.3 fps. As you can see the steam slows down a lot and it wouldn't cycle off on pressure as quickly. Others will chime in.

KC_Jones

I have 2-2" risers and a 3" drop header on my EG-40 which is half the size of that boiler. Do you really think the drop header would make a big difference considering how high that header is now? I know they work better, but with a standard header that high I would think he would be ok. I agree that is a "by the MINIMUM book", but on what I would consider a higher end install like this one it should have been above and beyond. Just another homeowner.

Don_197

I am betting you aren't in Texas......but your gauge might be LOL!!

http://www.ebay.com/itm/MARSHALLTOWN-MFG-THE-DUNHAM-HEATING-SERVICE-INSTRUMENT-TEMPERATURE-GAUGE-/151428407556?pt=Vintage_Car_Truck_Parts_Accessories&hash=item2341d62104&vxp=mtr

Don

ATM

I thought the near piping looked pretty good given some of the horror stories I've seen on here. It's a big improvement on what was on the old gas boiler. The header is I'd guess 35 inches above the waterline with the correct slope. I wouldn't think putting 3 inch pipes on the risers would make much difference on the overall velocity of the steam through the system. The mains look to me to be 2.5 inches. We had four bids and this one left me with the best impression it would be done correctly. I'm not as worried about the auto water feed. No underground lines and the wet return lines are either cleaned out or new. I have a feeling that will work itself out as the system gets skimmed a couple more times.

The installer is going to put in an additional Hoffman 75 to see if that helps on the pressure shut off issue.

Some additional pics

KC_Jones

You are correct it looks a lot better than many on this site. The comments are basically that it is good, but could have been better. There is a general consensus amongst the pros on here that the manufacturers recommendations are a minimum and most of the "steam men" always go above that. As far as the velocity what is being described is exit velocity from the boiler. The lower that is the less chance of sucking water out of the boiler. The idea is to keep the water out of the system and only have steam going beyond the boiler. So with those 2" tappings on the boiler your exit velocity is fairly high and are probably sucking water out of the boiler. Those are the velocity's that @dave0176 is talking about. Is it a problem for you? Only the operation of your system can say that for sure. I will throw this one out to the pros. If he is losing water in the boiler and taking on make up, is it possible the wet steam is causing this? In other words with wet steam the boiler is losing more water on a cycle than it should be. I don't know just a thought that popped into my head.

Abracadabra

1 -Add more main venting. The EGH makes steam a lot faster than than the old boiler.

2 - Is the waterline surging? If so, I'm guessing there's still oil left to skim. Oil on the surface of the water will make wet steam. The surging along with a lot of water thrown up into the mains will cause your feeder to add more water to boiler.

Jamie Hall

More main vents! It's almost impossible to over vent that system -- but you are well under. More main vents will help a lot.

Second, 12 ounces is probably a good cutout pressure. You might get away with 8 to 10. You might also try adding a snubber (such as http://www.omega.com/pptst/PS_SNUBBERS.html, pick one for steam usage to fit) to the connection between the vapourstat and the pigtail. They can make quite a difference.

Third, the question was asked -- when the boiler cools off again, having added water, does the water line come back to where it was, or is it now higher? If it comes back to where it belongs, more or less, -- that is, the water line isn't steadily rising -- you have a leak somewhere, which will need finding and fixing. Skimming -- valuable as it is! -- won't help a leak! On the other hand, if your water line is reasonably steady when the system is firing, skimming won't help either. If the water level is slowly rising with each shot of the feeder, though, then you may have a slow condensate return somewhere which is causing a genuine low water condition on firing.

Dave0176

Just to add a few more numbers the steam is leaving your boiler at about 32 miles per hour, with the 3" tappings you'd be leaving at about 14 miles per hour. This is just to give you an example of how fast the steam is leaving your boiler. The faster it leaves the more violent the water line will be, and the quicker the mains will pressurize.

nicholas bonham-carter

Definitely, more venting is needed, or putting the system into vacuum operation. Probably 4 gorton 2's, or a big steam trap, will be needed.
Insulation will help to dry out the steam exiting the boiler.
A 2- stage gas valve (do a search here for current recommendations on that), would help to moderate steam production as the pressure rose to a few ounces.
Valve off the auto feeder and see how the system behaves. Does it have a constant loss of water, or will the waterline return to normal when the boiler is at rest? Weil McClain show a so-called reservoir tank piped in at waterline height to help with the low water content of their boilers. A condensate tank and pump is not a good idea.--NBC
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butlermog

I'm in southwest Ohio as well and also have an EGH-85 (although mine is 20+ years old).
I have 2 Gorton #2 vents and a few Gorton #1 vents that I'm not using - so if we are close enough to each other you are welcome to use them in your experimenting.
I would also be very interested in knowing who you used to remove your old boiler and asbestos as I have the same situation. Please e-mail me if you're willing to share that info.

vaporvac

I used Rainbow for my near boiler piping asbestos, if that's any help. I kept the rest including the massive coal boiler. I'm not using that space and find it fascinating. Did I know you were in the neighborhood, Butlermog? I think ATM managed to find the one boiler company I never contacted, although I'm not sure they would have wanted my install.

ATM

Today I experimented by leaving the pipe open where the Hoffman 75s are located. Even with that the boiler short cycled on pressure and the differential. Soon after steam starts into the system the vent pipe alternates between positive and negative pressure and the boiler shuts off unless I crank the Main setting on the Vaporstat. Where the Hoffman vents (at the end of the main returns) never gets warm or generates steam that would close them off as far as I can tell.

How exactly is this supposed to work? There appear to be four small steam traps located on the top of the small yellow pipes that connect the end of the main to the returns as well as on the returns themselves. I thought that these were supposed to be serviced during the installation, but they don't appear to be when I look at them. I don't know if that could be causing the issue.

nicholas bonham-carter

If those crossover traps have failed closed, that would make it difficult for the air to get out, and would contribute to the short-cycling.
At the end of that return, there would be or would have been a hoffman trap, (information, and diagrams on this site, which I cannot find-Dan help please). The original system would have pushed all the air out, and the hoffman trap would not let it back in-a very sophisticated system for its time.--NBC

Bio

If you are still cycling on open pipe then your tstat may be the culprit, I would make sure is set to 1cph

ATM

Thanks Nicholas (and everyone else) for your input. The guys who installed the system didn't appear familiar with how an old vapor system is supposed to work. Their Weil-McLain distributor who I met though is very knowledgeable and has been very helpful including referencing Dan Holohan's books.

ATM

This is the trap I suspect could be the issue.

ATM

I heard back that the steam trap discs were supposedly replaced during the install.

ATM

butlermog said:

I'm in southwest Ohio as well and also have an EGH-85 (although mine is 20+ years old).
I have 2 Gorton #2 vents and a few Gorton #1 vents that I'm not using - so if we are close enough to each other you are welcome to use them in your experimenting.
I would also be very interested in knowing who you used to remove your old boiler and asbestos as I have the same situation. Please e-mail me if you're willing to share that info.

Rainbow did the asbestos removal

nicholas bonham-carter

Do you see any signs of those traps having been opened, (wrench marks, broken paint)?
You could take the temperature of the outlets, as steam is being made. If the pipe is hot, then they have ailed open, and if coll, then they are stuck shut.--NBC

ATM

Would it be worthwhile to service all of the steam traps? Could a few that have failed be causing this pressure issue? I'm sure they are original to the system.

nicholas bonham-carter

I would certainly check all the traps (including the crossovers), with a IR temperature gun. If the radiator traps are working properly, then no steam will get to them to close them, and air will flow freely out, letting in the steam. If one radiator trap is bad, then the crossover trap will close, and air will be trapped in the return, slowing, or impeding the venting.
To the best off my knowledge, changing the trap disk, will be seen as a new cap, and disk, so if the cap is old, then so is the disk, although it may work just as well as a new one.
Probably, the back pressure on your gauge should be a couple of ounces as steam starts to be made. A higher pressure reading would indicate a restriction in the system.--NBC

ATM

Any ideas on what could be causing a restriction? I pulled the 4 steam traps in the boiler room including the crossover ones and that didn't help as far as shutting down on pressure. I had the main cutoff on Vaporstat up to 14 ounces and it was still shutting down and short cycling. It cut back in at 2 ounces. The time between on and off was under a minute after about the first four minutes. Eventually even with the short cycles the thermostat was satisfied after about an hour as heat eventually moved through the system.

Fred

Are you sure it is short cycling on pressure? Was the boiler ever properly skimmed? Does the water in the sight glass bounce erratically? It is possible that the water is bouncing so much that the LWCO is shutting the boiler down.

ATM

I'm sure it's on pressure since I can kick it back on by raising the main cutoff on the vaporstat. I have the boiler rep and installers coming tomorrow to take a look at what's going on.

Techman

What would happen if there was a reducing/increasing coupling at the outlet of the boiler, and the riser was sized to the elbow?

Fred

Wouldn't that likely increase the pressure in the boiler? At best, it probably wouldn't make a difference.

Jamie Hall

A few posts back up the line there you (ATM) mentioned that with the vents off the lines where they are located the openings started showing positive and negative pressure soon after the boiler started.

This indicates that somewhere in your system steam is encountering water, or possibly excessive cooling, and is collapsing -- forming a momentary vacuum -- and then getting more steam and so on. This is not supposed to happen! It may simply be that you have very wet steam. It may also be that you have a real problem with pipe insulation. It may also be that you have some sections of main which are trapping some condensate.

Whatever, that particular symptom suggests to me that you need to really thoroughly look at your whole system to be sure that you find out what is happening, and where.

On the crossover traps. They are absolutely critical to the way this type of system functions. Do get an IR gun (they aren't that expensive) and check them. The inlet -- steam main -- side should get steam hot fairly quickly (it varies with the system), and the outlet (return) side should get hot or at least warm -- but definitely not steam hot.

ATM

I'm back from meeting with the installers (including their head steam man) and the boiler rep to show them what was occurring. The conclusion they came to is that it's due to a dirty boiler. They thought once they get the oil and contaminants totally skimmed (and it may take a number of times) that the problems should cease and the system run smoothly without short cycling. The boiler rep pointed at how violently the gauge glass was going up and down when it went off on pressure.

I wasn't there when the boiler was run the first time after it was installed, but it's my understanding that it didn't cycle on pressure even at 4 ounces It was only after all the cutting oil came back after the first cycle that this became an issue. Hopefully that's the case and it gets resolved over the next few weeks. They will also replace the 2 Hoffman 75 vents with 2 Gorton #2 vents. Thanks everyone for your feedback and suggestions. I will post in update in the not too distant future.

ATM

After a number of skimmings the boiler seems to be functioning well. Insulation was put on the basement pipes last week and the low water cutoff hasn't added water nor has it short cycled in the last month or so. Thanks again for all the help I received on this board.

KC_Jones

Thanks for the update!