Converted to Gas from Oil last year and I REGRET IT BADLY!!

Just to be clear. Was the whole boiler replaced or only the burner?

If you can determined the actual delivered cost of the two fuels, this calculator crunches the numbers.

Perhaps the old oil burner was running 80- 82%, maybe lower?

. A new gas boiler properly sized and installed should run 85-87% efficiencies. Maybe use those numbers in the calculator.

https://coalpail.com/fuel-comparison-calculator-home-heating

The NYSERDA website has historical data on various heating fuel over many years. This shows heating oil costs in you area over a 20 year period.

You can do the same with NG

you’d have to tell us the $/therm and the $/gallon to make any judgements.

Any other appliances on gas? You mentioned a dryer. Stove or outdoor barbecue?

An improperly installed boiler or oversized boiler can cause excessive fuel consumption also.

A look at the gas bill would show how much you pay monthly just for the privilege of being connected to the grid. And any other bendover fees.

What size is that boiler?

It literally has no piping and no flue connector.

Don't blame the boiler. or the fuel. it's looks like an installation issue.

It looks like your Hartford loop is too high and the condensate return should have been piped down below the Hartford loop tee then back up and connected to the tee to create a trap. this will prevent a bouncing water line from sending steam into the return. The way it's piped you are getting steam in the condensate return. Hard to tell exactly the level of the Hartford loop water level.

I agree with pedmec, it is piped wrong. With all that they should have piped in a double drop header too in my opinion.

The riser from the boiler to the header looks smaller than 2-inch- might want to verify that.

@KeefWeef , there are plenty of Steam Guys on LI. Go here:

https://heatinghelp.com/find-a-contractor/state/NY/

I just looked at the installer's website and sent them a message about how poorly the workmanship is in that photo. I wonder what will happen when the people read that message?

I sent the photo link, and I send a link to https://www.heatinghelp.com/store/detail/the-lost-art-of-steam-heating-revisited/ and said they need to read this book… Then go back and make it right.

Your piping should look more like this

So I guess natural gas isn't the villain in this story after all?

This is what I am sending them:

The near boiler piping looks almost as specified by the manufacturer.  It appears that there are two steam main risers from the old boiler photo.

  It also appears that one of the risers to the main is connected to the header behind the vent connector pipe (incorrectly called smoke pipe). If your pipe size is 2” as it appears to be, I believe that your header is correct, although a better steam boiler fitter would have used both boiler tappings and even used a drop header.  But you are fine with the minimum requirements.  

Where I see a problem is in the return piping.  With the old boiler the water line was higher and a tee fitting on the return from the end of the mains would have been below the water line and therefore have trapped any steam from one main from affecting the other main.  (see the Tee with pipes A, B, and C) Now that the tee fitting is above the water line, there is a possibility that you will get “water hammer".  Sometimes “water hammer” can be violent enough that old pipes can start to leak where they would otherwise have been just fine for another 20+ years or so.  

So the first thing you need to do is to get the two dry returns that used to be wet returns to be piped below the water line and then the Tee fitting to connect them should be near the floor. (since the new water line is much lower).  The next error is the fact that there is no Hartford loop. 

This is an arrangement of piping that the Hartford Boiler Insurance folks required over 100 years ago in order for boiler owners to get their boilers insured.  This piping configuration has been adopted as a standard for all low pressure steam boilers used for heating systems in residential and light commercial installations.  

Your boiler’s Hartford loop area is piped as a dry return connecting to the equalizer (the pipe that lets condensate from the header drain into the return)  from above (see green pipe in the illustration) , not from the floor up to the Tee on the equalizer using a close nipple as required by the boiler manufacturer diagram (see the blue pipes in the illustration).  This is another possible water hammer and noise location.  

And one other item that I see that has nothing to do with the near boiler piping but shows that there needs to be some training for the installers is the fact that they used metal duct tape to connect the vent connector (often called smoke pipe).  That is an improper use of metal duct tape and the flue connector pipe should be fastened with screws only since it is a category 1 vent system.  Any leaks in the piping will be from the boiler room into the inside of the pipe so there is no need for an air tight seal.

I hope that when the installing contractor sees the error of their ways that they will offer to make the proper piping changes at no charge even if you do not elect to have that same contractor do the repairs on the leaking sections of the steam pipes.

As far as the rest of the system and the leaking steam main pipes that are not near the boiler, since it can not be verified that the leaks were a result of water hammer as a result of an improper boiler install, or the fact that just putting a wrench on an old pipe can cause it to leak. and since the contractor did not include replacing any system piping past the near boiler piping, I  believe it to be the homeowners responsibility to pay for any leaks that are present in the system piping not near the boiler.  Those pipes are close to 100 years old and are subject to consequential damage from anyone working on them. That is what you should expect in a 100 year old home.  If you want a guarantee on all the pipes in your home then you need to purchase a new home with a home warranty. 

@KeefWeef

From all the comments above you surely will notice that the near boiler piping is incorrect. It is thought that the boiler is also too large.

Get a hold of the owners manual/installation instructions and work your problem from there.

It might just get you some satisfaction. I hope things work out. See @EdTheHeaterMan 's good advice.