Boiler over sized, do I need a 2 stage gas valve?

nier01

Hello guys,

My boiler is Weil Mclain EG45.
I found out thru this good site that my near boiler piping is under sized and re-piping is on the way.
The boiler also cycles before satisfying the thermostat.
The vents hisses almost quiet on 1st cycle but 2nd cycle hisses loud.
I already have 2x Gorton #2 on the 25 feet 2 inches main.
I'm trying to figure out how big or oversized my boiler is and if I need to install 2 stage gas valve.

I dont know to size actual boiler size needed but I have calculated the total EDR of all radiators.
The radiators EDR total is 213.25 no multiplier yet.


Thank you very much.
Nier

ethicalpaul

Here are the sizes of the WM boilers: https://www.weil-mclain.com/products/eg-gas-boiler

Compare your radiated EDR to the Net sq ft steam number. You’ll see the 45 is too big for your stated EDR.

If I recall correctly from my reading on this site, you can turn a 45 into a 40 by getting a new burner/orifice set. You’ll probably want a tech to install it for you and do a combustion test/adjustment.

I think @KC_Jones has a two stage burner on his WM, maybe he’ll tell you about it

ChrisJ

You need a new burner manifold, rear burner support and draft hood to convert it to an EG40.

This should of course only be done by a professional.

Dave0176

nier01 said:

Hello guys,

My boiler is Weil Mclain EG45.
I found out thru this good site that my near boiler piping is under sized and re-piping is on the way.
The boiler also cycles before satisfying the thermostat.
The vents hisses almost quiet on 1st cycle but 2nd cycle hisses loud.
I already have 2x Gorton #2 on the 25 feet 2 inches main.
I'm trying to figure out how big or oversized my boiler is and if I need to install 2 stage gas valve.

I dont know to size actual boiler size needed but I have calculated the total EDR of all radiators.
The radiators EDR total is 213.25 no multiplier yet.


Thank you very much.
Nier

An EG30 would’ve suited your needs just fine.

nier01

Thank you guys for the replies,
Would converting this eg45 to eg40 more economical than completely replacing it with actual eg40?
Or should I just install 2 stage burner.
Again thank you!

KC_Jones

If you change the components to the EG-40 it is an EG-40 at that point as the blocks for the 40 and 45 are the same.

I take no responsibility for this, but I fired my previous 45 with the 2 outer burner tubes removed for 10 years with no adverse effects that I am aware of. Boiler died after 32 years of service. Even with 2 removed you would still be over sized, that’s how far off you are.

If you are contemplating another boiler, as Dave said a 30 would have been the proper choice.

nier01

Thank you @KC_Jones, @Dave0176, @ChrisJ, @ethicalpaul,

I found out many things thru this site! Truly this is the go to when you need help with anything about heating system. Thank you all.

My boiler install is all messed up from boiler sizing to near boiler piping. That said, I'm thinking of how to correct this properly. I know re-piping is needed but the boiler is still over sized.

Option 1 - Is to replace it with proper boiler size and pipe it properly. But the cost I already put up money on the WM EG45

plus
what Im gonna do with WM EG45?
Can I sell it ?

Option 2 - Re-pipe , convert to EG40.....
maybe install 2 stage burner?? And I can keep the EG45.

The current boiler actually heats up the all radiators
BUT the noise from vents and the banging at night is terrible.
AND the faint smell of rust I think because of high velocity.

I know replacement is best but economically wise would Option 1 be the almost same cost as Option 2?

Thank You Again
Nier

ChrisJ

In my opinion reducing it's output is also going to reduce it's efficiency.

The correct thing to do is have an EG-30 installed with the proper piping.

The cheapest option may be to have it converted to an EG-40 and do what you can with the piping to make it work. I don't know how bad your piping is, and I don't think I've seen any pictures of it.

Personally, I'm against reducing the output of the burners for the simple fact that excess O2 will go up resulting in reduced efficiency. It just doesn't make sense in my mind. But, I've been wrong before.

nier01

Thank you @ChrisJ.
I will consider replacing it with EG30.
I will call a pro to weigh in my options.

If I go with re-piping the near boiler.
Will 3 inches riser and 3 inches drop header enough to lower velocity and produce dry steam?

ethicalpaul

If it were me, I'd fix the piping (you were going to do that regardless anyway I think), throw a Big Mouth on the main vent, make sure the boiler is skimmed and is cutting out at 1.5 psi, and then see what happens.

If it was dramatically short-cycling on pressure after that under normal operation (not including setbacks), then I would get a quote to have it converted to a 40 to see what that would run.

Then I would see about more drastic measures after that *if needed*

ChrisJ

A 3" header may help.... aside from that the piping isn't terrible.

Danny Scully

The header is reduced on the horizontal, that’s terrible @ChrisJ

nier01

Thanks @ethicalpaul,

I'am going to have the pipe fixed, (that's my first plan before learning that the boiler is too over sized)
I called a pro.
He suggested 3 inch riser and 3 inch drop header.

I'm thinking to make it 2 risers and drop header if that makes drier steam and lower velocity. But I don't know if he will agree yet.

With regards to boiler psi. My pressuretrol is not reliable.
I set the cut in to 0.5 and cut out to 1.0 But actual is cut in 0.5 and cut out 2.8. I tried to calibrate the pressuretrol using @Fred 's procedure the lowest cut out I can do is 2.4 but cut in goes down too about 0.1 the actual difference between limits is always 2.3.
Right now on cold start 1 deg F difference on thermostat, the boiler cycles about 15 mins not less.

The all radiators heats, I just can't deal with the venting hisses and banging
and hint of rust smell (daughter too sensitive to smell)

ChrisJ

Danny Scully said:

The header is reduced on the horizontal, that’s terrible @ChrisJ

No,
Terrible is no header at all with an "equalizer" coming out of the side of it.


The piping in the picture still drains and the tall 3" riser likely doesn't pull a huge amount of water out of the boiler.

ethicalpaul

> @ChrisJ said:
> The header is reduced on the horizontal, that’s terrible @ChrisJ
>
> No,
> Terrible is no header at all with an "equalizer" coming out of the side of it.
>
>
> The piping in the picture still drains and the tall 3" riser likely doesn't pull a huge amount of water out of the boiler.

Or does it?

> The all radiators heats, I just can't deal with the venting hisses and banging

ethicalpaul

I think if you get a working ptroll and get a Big Mouth vent that will help your hissing

nier01

The header is undersized and the producing wet steam and high velocity steam.
Is a 3 inch single riser and 3 inch header will be enough to slow down the steam?
and boiler is oversized.

nier01

Thank you @ethicalpaul ,

I'm, thinking vaporstat 0 to 4 psi. But with oversized boiler could setting 0.5 cut in and 1.5 cut out would make it cycle more?

My main is about 25 ft and already have 2x gorton #2.
I would add a 3rd one if it will help the silencing the vent hissing.

ChrisJ

nier01 said:

The header is undersized and the producing wet steam and high velocity steam.
Is a 3 inch single riser and 3 inch header will be enough to slow down the steam?
and boiler is oversized.

If it was mine, I'd pull that elbow off of the top of the riser and put a 3" x 3" ell, with a 3" header. I'd then point a 3" x 2" ell straight down at the end and run that into an equalizer.

You can come over at an angle with the equalizer if you have to, but pipe it so the header drains down into it well.

If you want to get a little fancier, use a 3x3x3 tee in the header and run a 3" stub up a few inches and reduce it into the main. This will keep speeds in the header lower and reduce the chances of pulling water up into the main.

nier01

Thank you @ChrisJ,

I will try to propose what you said to the pro.

ethicalpaul

nier01 said:

Thank you @ethicalpaul ,
I'm, thinking vaporstat 0 to 4 psi. But with oversized boiler could setting 0.5 cut in and 1.5 cut out would make it cycle more?

My main is about 25 ft and already have 2x gorton #2.
I would add a 3rd one if it will help the silencing the vent hissing.

My thinking is that with your situation a vapor stat will give no benefit over a regular pressuretrol.

And yes, setting the cutout to 1.5psi will result in more cycles than if you set it at 4 psi, but you are just pushing steam into your system that already has steam in it, burning fuel $$ for no gain except for more hissing and spitting.

But see how it performs after fixing the pipes and getting the pressure down...there are worse things than cycling on pressure

nier01

Ok then, I will ask it to repipe and see how will the system behaves. Hopefully better and quiet. Thanks everyone.

ethicalpaul

Don't forget to get the pressure down too and let us know how it goes!

JUGHNE

Can't see above the main riser, is there only one main in the house or another main tied in that we do not see in the picture?

Dave0176

I’d go with two three inch risers drop it into a 3” header, install a vaporstat and two stage gas valve, and get the components to drop it down to a EG40. This will all help not correct the problem, the correction is a proper sized boiler.

nier01

@JUGHNE
The main riser is slanting from the header and there is only one main.
Thank you.

nier01

@Dave0176 ,
I agree with you Dave,

from my reply to @ethicalpaul I said:

I'm thinking to make it 2 risers and drop header if that makes drier steam and lower velocity. But I don't know if he will agree yet.

I will ask the pro to design the near piping like that.

My question with the 2 stage valve is CO, should oxygen increase be a concern for me? or It will be fine as long as the conbustion test is ok.

Thank you
I appreciate everything.
Nier

nier01

@ethicalpaul,
Don't forget to get the pressure down too and let us know how it goes!

Yes thank you!