Another oversized steam boiler question

pm124

I made the mistake of reading up on this too late. I received a number of quotes to replace my 40 year old Weil-McLane. All wanted to replace the old boiler with the same BTU rating as the new one. I live in a house with a newly closed cell spray foam insulated roof and just 2400 SQFT of heating space, but the boiler is 175,000 BTU. The calculators suggest I need about 78,000 BTU-120,000 BTU. It is a steam system that is gas fired. The job is half done now, and the new boiler is ready to be installed downstairs. Do I ask him to replace it with a smaller boiler?

Paul48

What is the combined EDR of all your radiators?

EzzyT

I'd have the company whose doing the work to hold off on the work. And just as Fred mentioned find out what the total combined EDR is

kcopp

Spray foam and insulation has no impact on the boiler size..... All has to do w/ the radiators.
You need to measure out all the radiators to properly size the boiler. A competent installer should have known that.....

pm124

All the candidate plumbers save for one wanted to just replace like with like since the system more or less worked before. I will attempt to calculate the EDR and re-post. Thanks so much. The higher efficiency of the new boiler is also not a consideration? That is, the newer 175K boilers simply use less input than the old ones? Both were rated as 140K out, 175K in. Very similar. 40 years apart. The pipes didn't even come close to fitting.

Fred

Size the new boiler based on the connected total radiator EDR. Compare that total EDR to the Sq. ft. of steam rating on the new boiler plate. That number will have the piping and pickup factors already factored in so Total radiator EDR matched as closely as possible to the Rated Sq. Ft. of Steam on the boiler plate.
Don't let them bush down the riser tappings in the boiler. The risers work best (less steam velocity) if they are the size of the boiler tappings.

Jamie Hall

It's all in the EDR for steam systems. The efficiency doesn't count (except to make running it a little cheaper!). The insulation doesn't count (except to make running it a lot cheaper). The installed boiler must match the installed EDR, plus or minus about 10 percent. No other way to do it right.

Paul48

Please don't tell us they are re-piping with copper.

PinkTavo

If the envelope has been upgraded with insulation, then do a room to room heat loss calculation. Then you may be able to eliminate some radiation or down-grade the EDR by replacing with smaller radiators to make the new total EDR match the loss. Still match boiler to EDR, but it will be a smaller boiler. I did this and it worked perfectly. I eliminated two radiators (the floor plan changed) and downsized two.

ChrisJ

I would also recommend sizing the boiler smaller than typical for the radiation in such a house.

For example, use a 15-20% pickup factor rather than the typical 33%. You could even go smaller, but all of your piping needs to be well insulated, pitched and venting must be spot on.

First step is still calculate your current EDR. Also share pictures of the radiators and all of the piping with us, especially the boiler. Boiler piping is critical.

pm124

Thanks so much everyone. What a wonderful community. Calculations and pictures forthcoming after I return from the office today.

JUGHNE

Is this one or two pipe steam? Some pictures of your typical radiators would be appreciated.

pm124

pm124

This is one of the radiators.

ChrisJ

Wow that's some ugly work. That's the new boiler!?

pm124

I can't seem to find an EDR calculator that matches these radiators. I feel like an idiot. This post is basically just for public consumption at this point, as the radiator is in and working well. It's just that there seems to be less posted online about sizing steam boilers than other boilers.

Steamhead

The header looks like it's only 2-inch. Those
Weil-McLain EG-series boilers have 3-inch steam outlets. What is the exact model- probably PEG-something?

pm124

Here is a link to the entire album.

pm124

It is an EG/PEG-50. Thanks much!

KC_Jones

Certainly looks like 2" pipe, which means it's wrong. The manual clearly states 2 1/2" at minimum. And (IMHO) minimum means the lowest quality install you can get. So you didn't even get that. Did you make final payment to this contractor?

New England SteamWorks

The link doesn't work?

Very ugly work, right down to the furnace cement...

Don't make final payment on this one until we see more. You at least deserve the minimum standards.

Paul48

I'd like to see a better photo of the Hartford loop to the sight-glass.

pm124

Whoops. Sorry, I think I fixed the link, here. I will post the picture of the Hartford loop.

KC_Jones

They cheaped out and reused the piping from the old boiler. That header doesn't look like it's the correct size. As I said it is supposed to be 2 1/2" min. so they didn't pipe to manufacturers spec. I guess another contractor that can't read? Did they even pull the manual out of the plastic before doing the work?

ChrisJ

There's also no skim port and judging by how much dope they used you're really going to need to skim that boiler, a lot.

The entire thing is a sloppy mess.
Is this a licensed contractor or a handy man install?

pm124

He was a licensed contractor. I will call him back to install a skim port and correct the undersized piping. Anything else I should do? Is this thing going to be less efficient?

KC_Jones

Just out of curiosity, where are you located?

pm124

I did a lot of looking online. It is almost impossible to find a good boiler installer. There are no criteria to judge by. I tried two 5 star, multi-review contractors on Yelp. One seemed very knowledgeable, but wanted to charge 4 times as much for the install. The other didn't seem to know answers to some of the basic questions I asked. (I asked various questions that people on this forum thought were important to ask.) This guy came in at the lowest bid and knew the answers to basic questions.

In total, I looked at 5 contractors. Two gave quotes over the phone without even showing up. This was one of the two who showed up.

EzzyT

Wow what a mess. Personally I wouldn't of piped that boiler with no less then a 3" drop header with King and return valves.
Make sure that boiler is skimmed really well just like others have mentioned. Plus make sure they do a combustion analysis with a combustion analyzer

EzzyT

We don't discuss pricing here

ChrisJ

pm124 said:

I did a lot of looking online. It is almost impossible to find a good boiler installer. There are no criteria to judge by. I tried two 5 star, multi-review contractors on Yelp. One seemed very knowledgeable, but wanted to charge $******for the install. The other didn't seem to know answers to some of the basic questions I asked. (I asked various questions that people on this forum thought were important to ask.) This guy came in at $***** and knew the answers to basic questions.

In total, I looked at 5 contractors. Two gave quotes over the phone without even showing up. This was one of the two who showed up.

We aren't allowed to discuss pricing here and I would edit your comment to avoid upsetting anyone, but I can tell you as a DIY homeowner, it cost me literally double to install my own stuff properly than what you paid someone.


Sadly, you got what you paid for and I'll be honest, as a homeowner you have no way of knowing what you're getting ahead of time. This was a big part of why I did the work my self. I honestly have no idea how someone is supposed to find a good contractor without word of mouth.

Please edit your post and remove the pricing though.

pm124

I'm New York City. If anyone know who can come and fix this mess, it would be appreciated.

pm124

I'm so sorry that I forgot about that rule. I have edited the post!!!

ChrisJ

pm124 said:

I'm New York City. If anyone know who can come and fix this mess, it would be appreciated.

@JohnNY Could.
@EzzyT May go out there too, not sure.
@Dave0176 May as well, not sure.

EzzyT

Send me a private message

Fred

Oh my gosh. That contractor should be banned from the trade. My priority wouldn't be on skimming, at this point (even if you had a skim port). It would be on getting that mess properly installed. He definitely should have used a larger header and both riser tappings out of that boiler. Why all that dope on those joints? Did he fire that boiler up and find small leaks that he assumed he could resolve with pipe dope? It looks like he took some tin snips and hacked away on that side panel. What's that about?
BTW, go to the store tab at the top of the page on this site and buy the book "Every Darn Radiator" by Dan Holohan. It will give you the EDR ratings for just about every style/brand radiator by section.

EzzyT

I'm going out there tomorrow morning to assets the damage

pm124

OK, buying the book! Any others I should read.

ChrisJ

pm124 said:

OK, buying the book! Any others I should read.

Greening Steam is my favorite.

But I'm weird.

pm124

Weird is good. I bought his other book The Lost Art of Steam.

Fred

EzzyT will take great care of you! Get the job done right.