is steam boiler undersized

peterweiner

I just had my Weil Mc boiler replaced from EG75 to EG50 plumber says old boiler was oversized.All radiator estimated BTU <= 100,000 The pipe off the boiler goes to a tee with 2 pipes feeding front and back of house. The first pipe off the T goes to all the radiator in the back of the house and the second pipe to all radiator in front of house Now all the rad coming off the second pipe dont heat up properly it takes 45 min for living room or bedrm rads to heat up and they are directly above boiler The rad on the other sides of these rooms ( fed by the first pipe off the T)heat upinstantly) My daughter room further downstream doesnt heat up even if boiler on for 1. 1/2 hr and room on 3rd floor no heat :Its as if not enough steam reaching the second pipe?Plumb er say boiler not undersized and its a redistribution issue but they havent fixed it They checked pipe pitch puti n a new #1 main steam vent This never happened when I had larger boiler
with old boilerCould it be undersized

ChrisJ

We need a lot more information.
Is this a two pipe or single pipe system?

Can you give us pictures of all of the radiators and the new boiler with it's piping?

Could it be undersized? Sure, but I wouldn't assume that at this point. If your estimated btu/h is less than 100K even an EG-50 seems a bit oversized honestly. Your old boiler may have been oversized and covering up other issues.

But let's see the pictures and see what we can do to get your system working well.

peterweiner

tryin g to add photo wont allow m,e to add it

peterweiner

peterweiner

one riser of boiler then header goes to two takeoffs
problem is the. second takeoff ot filling with radiators with steam for a LONG time first take fills all radiators alm,oist immediately

peterweiner

there are also 2 tankless coils that supply hot water off boiler to baseboard radiators in basement and kitchen( you can see circulator pump in picture) BUT I have the thermostats turned off --they are not in use right now

STEAM DOCTOR

Boiler piping is not good. To put it nicely. Single 2-in is undersized. And that second "header"  might be trapping water. 

realliveplumber

aah the old single header into a double header trick.......

first, open the installation manual, and have it piped according to the instructions.

then report back if there is still a problem.

dabrakeman

Check the pitches of the pipes. Not theoretically correct but will call it two headers upper and lower for now for simplicity. The upper header should be counterflow in your case thus pitched so condensate can run back to the boiler. Otherwise water can get trapped in the 90. Bad piping arrangement here resulted in an unnecessary counterflow setup near the boiler. IF you look in the WM installation manual (available online in WM site) you can see how the piping should have been arranged.

KC_Jones

I doubt you are undersized, but the piping they installed appears to be, which will restrict flow and cause excess carry over.

Weil Mclain specifies a 2 1/2" (2 7/8" OD) riser pipe with similar sized header. For me it should be 3" because the tapping is already that size, but given what the contractor did already getting anything above spec would be a pipe dream.

Contractor needs to come out and repipe the boiler properly, on their dime. This includes bringing each of those mains into the header individually. You are trying to feed the entire house through a single 2" connection off the header.

Keep in mind, it doesn't matter if it's been like that before, the boiler was changed and when a system component is changed, the entire thing needs to be looked at.

After that is resolved, need to skim the boiler to remove the oils due to new piping and new boiler. After all that the boiler should be running correctly and you can address the balance issues you are having.

I'd also suggest you need to insulate those pipes as that will definitely slow down the distribution, especially with all the copper I see.

So for main venting, how long are your mains? Venting needs to be size according to how long the main is, and unless you have a very short main, a single #1 vent isn't enough. Also, need to make sure you have main venting on both mains.

Intplm.

@peterweiner

There is a term called "near boiler piping" that is required for a steam system to work at its best.

You do not have that.

As @realliveplumber says above. look at the directions.
For starters,
The boiler needs to be piped as the directions state.

peterweiner

i want to thank you all
Plumber is coming back today
I will show him your comments

ChrisJ

peterweiner said:

i want to thank you all
Plumber is coming back today
I will show him your comments

At this point, my recommendation would be have him replace this with 3". Exactly what he did there, but in 3".





a single 3" pipe is more than twice the volume of a single 2" pipe and it makes a huge difference in this application.

peterweiner

but is the rest of it piped correctly tot the two takeoffs?
im looking at install manual is the riser dirctly from the boiler to go to a header and then go back down at a 90 degree to anothe header?

Waher

It would be better for the plumber to add the 3” header and have the two 2” risers off separate tees on that 3” header rather than what’s there now sharing a single riser which probably is getting filled with counter flowing condensate the way it’s piped now. It would be easy to do a drop header up high, over to the left, down under the two risers, and into the equalizer 

SgtMaj

Near boiler piping is wrong, regardless if you didn’t have the issue with the old boiler. It needs to be piped according to the installation instructions. Call back your installer and have him fix it.

ethicalpaul

Sorry to be a wet blanket, but keep in mind that even if the near boiler piping is all made good, there could be other issues preventing areas of the house from getting heat such as bad pitch on a main, etc.

ChrisJ

ethicalpaul said:

Sorry to be a wet blanket, but keep in mind that even if the near boiler piping is all made good, there could be other issues preventing areas of the house from getting heat such as bad pitch on a main, etc.

One step at a time.

peterweiner

thanks
yes that was looked into
they tried to pitch that takeoff as best they could
still all radiators taking inordinately long time to heat
and didnt happen with older larger EG 75

peterweiner

although many of you refer to Weil mclain installation manual the only thing i see in installation manual is that riser off header has tobe 2 1/2inch not 2inch
there is nothing else about piping beyond that point
where do i find that

delcrossv

Each main should be connected to the header individually. Although the manual shows one connection, that implies if you have one steam main. Going to the largest available size (3") for the riser and header wouldn't hurt either.

KC_Jones

peterweiner said:

although many of you refer to Weil mclain installation manual the only thing i see in installation manual is that riser off header has tobe 2 1/2inch not 2inch
there is nothing else about piping beyond that point
where do i find that

There are industry accepted best practices with piping, so not everything is in the manual. The fact that the installer here is short cutting on even the pipe size specified in the manual, for me, shows how much they care about best practices. By the looks of what they did, they are primarily concerned with getting in and out as fast as they can to maximize their profit margins. I believe there are manufacturers that spec each main tied in individually, Weil Mclain isn't one of them, but it is still an industry accepted, best practice that the contractor should do.

The 2 1/2 is a minimum and you will definitely have issues until at least that much is resolved. As @ChrisJ above stated, I'd push them to just get that to 3" and be done. It's probably the most you can expect from the company you are currently doing business with.

I'd also say, given the amount of copper I see, this isn't the first time an uneducated contractor has worked on that system. So you probably have a compounded problem.

The issue, often times, is that a contractor at some point replaced the original boiler, and just followed what was there. The problem with that is, new boilers are made different from the old ones. Smaller steam chests, possibly different fuel etc. In that situation the educated contractor knows to look at the system, and all the piping and ensure they are installing the new boiler not only to manufacturers spec, but with best piping practices in mind. It appears your home has had several in that did not do this, and now you are stuck with trying to resolve several contractors poor practices, and are finding it out after the fact.

SgtMaj

Just make sure that all the pipe sizes are in accordance with what is spec’d in the install manual, and that includes the equalizer. I’m still amazed that some installers can’t decipher a drawing of near boiler piping.