I don't know what you pay for oil, or what you pay for natural gas. My guess is that gas would be much cheaper. I pulled info from your area below.

I can tell you that generally, natural gas is one of the least expensive ways to heat your home or water. Usually electric resistance (what you have) is the most expensive way to heat water (by a lot).

To move beyond these general statements would require knowing your rates for gas (per therm), electricity and oil.

I'm not an oil boiler person - but I'm going to bet that's pretty low efficiency boiler (65% or less) based on the flue and age. If true, 35 cents or more of every dollar you spend heating the house just goes up the flue.

Compare that to a condensing gas boiler which is 92-95% efficient and potentially much smaller.

I did some quick googling for rates in your area and I came up with:

Oil: $3.71 per gal

Gas: $0.448315 per therm

Electricity: average $0.233 per kwh

When you convert that to a common measure (a therm) at 100% efficiency, the cost of 100 therms of energy would be:

Oil - $267 or $360 with a 65% boiler (edited to show correct value for #2 heating oil).

Gas - $45 or $50 with a 90% boiler

Electricity: $683

Given this information, I'd be talking to some knowledgeable boiler folks about changing to a condensing gas boiler. Your existing is 60 years old, usual lifespan is 30 to perhaps 50 years. You are overdue.

As for the water heater, you could go with the indirect tank shown in the brochure or tankless.

The largest residential tankless gas water heater (199k btu/h) would heat about 6 gallons per minute if the incoming water temps were 40F (winter). That's about 2 showers at the same time (2.5 gpm each) + a little left over (again, in winter). A tub is 4 gpm. So, you could fill your tub and take a shower - but that's pushing it. In the summer when your inlet water temps are warmer, it would be no problem. If you have hard water, you will need a softener - so that may negate space savings of a tankless.

House blowing up isn't a worry.

These are general ideas to get you pointed in the right direction.

I'm considering converting to natural gas in order to gain space in my laundry room...

The primary goal for this oil to gas conversion is to make the laundry room larger. How many square feet of space do you hope gain? A gas boiler will likely be smaller than the current oil fired boiler, but not by much. A 50 gallon electric hot water heater is about the same size as 50 gallon gas hot water heater. If you really want to maximize the space increase then look into a combination boiler. It operates as a boiler and tankless hot water supply. It would be hung on the wall and free up the most floor space.

Gas runs along a street on the side of my house, so I checked and its accessible.

PSE&G LI and ask what it would cost to bring the the gas line into your basement. It may be subsidized for new hook ups.

I have baseboard heat. Oil burner with outside oil tank...

Is the tank above or below ground? If it below ground the tank will have to be removed or properly cleaned and filled.

I am VERY concerned with getting ample hot water...

Dishwashers use a few gallons of water and are not a problem. The number of shower heads and the size of your bath tub factor into this. A 50 gallon gas hot water heater with 50,000 BTU input should be able to handle this. A tankless hot water heater or a combination boiler may not be able to supply enough hot water simultaneously, but will be fine if the shower and bath are taken consecutively.

Will my NY cold weather cause me to pay more for heating with gas rather than oil?

Your heating costs will go down. My rough estimate the costs would be about half what your normally would pay. If you supply the rates you pay a calculation can be done for comparison.

If you think YES DO IT, what maker is best? what unit is best?

The brand is not nearly important as the installation. Talk to the company who currently services your oil burner. Get 2-3 quotes and ask about the combination boiler.

What size should i get? Should i keep my electric water heater tank?

The installer determines the size. If you keep the electric water heater you won't gain as much space.

@mike_home

Regarding combo boiler:

I'm admittedly not a boiler guy, but that setup looks like it's using high temp emitters - not the new low temp ones that would work with a combo boiler. I think they are looking at a cast iron boiler. Otherwise, yes- a combo boiler would save a lot of space.

Just re-doing that pipe maze would do wonders for saving space.

I agree that tank water heaters are going to be the same size, regardless. I also think a tankless is not going to be the space savings anticipated once you add in a water softener - which they may need if they have hard water.

I think the primary opportunity for space savings is to install that in a compact way with the routing of pipes and such.

Regarding size of tankless: If you go tankless, you always get the largest (200k btu/h). There's no benefit to getting smaller. You may not need the maximum gpm in the summer, but when the inlet water temps drop, the gpm goes down quickly. And a gas tankless will throttle the gpm through the unit to maintain the set temp.

I am not an boiler expert either. I have also read on this forum people having problems with combination boilers. Proceed with caution if you are going to install a combination boiler.

I don't think Long Island has a hard water problem. But this may vary depending on where this home is located.

Regarding hard water - my mistake: I had her confused with a different thread who said they had "moderately hard water". She did ask about a "descaler" though. I edited my response to reflect that.

" Gas: $0.448315 per therm "

Another example of misunderstanding and misinformation from this person. This suggested amount is nonsense.

This may be the cost for the gas itself, but I believe there's a "delivery charge" for each therm of close to $2 per therm. Add the two together to get the cost.

Stick to what you know, whatever that may be. This topic doesn't seem to belong on that list.

Aren’t there delivery charges for each kwh? Gallon of oil?

@Elmer J Fudd

Look buddy, you have an ax to grind and it's really getting old. Go do it elsewhere.

I made it very clear I don't know what the costs are and those were results of a google search.

Yes, there are various additional charges for all of the types of fuel, including oil and electric, various rate structures, etc. In addition, the costs of the fuel change by time of day (electricity) to time of year and market conditions for oil and gas. Getting to the delivered cost of each fuel type isn't possible without much more work - and even then would be a guestimate.

But the cost of gas per therm was indeed shown as 0.448315 per therm. (Nov 2024, column 1).

The delivery charge is $22 for the first 3 therms and another $4.05 for the next 47. (residential heating)

" I made it very clear I don't know what the costs are "

We can agree on this. Don't present what you've found from searches without understanding the information you have, and then pretend you know what you're talking about.

You said above that gas is $45 for 100 therms. It's likely 5 times that or more.

To get back to the issue at hand: Although the primary motivator for this project was to save space, potentially with a tankless gas water heater, it's my opinion that the 60 year old boiler is well beyond its service life. That should be a priority, with the possibility of saving space by redesigning both the boiler and domestic hot water - as well as all of the associated plumbing in that area that has sprawled over many years. That might be a condensing cast iron boiler, or a combo boiler. The water heater might be gas tankless, indirect tank, or something else . Certainly a switch from oil for heat and electric resistance for DHW to condensing gas (90%+ efficient) would be wise.

There are other things to consider, such as venting, rebates available, cost of installing gas service and decommissioning the oil tank, etc. Not to mention overall budget of such a project.

Talking about brands, sizes, etc. is way premature.

We have pointed you in the right general direction.

Talk to a few boiler folks and get proposals. They would be a good local source and can provide more specific information on what's possible and what it would cost.

thank you everyone for your wisdom. Jake, i thought i gave enough info but realized i never said my existing unit is cast iron and my oil tank is above ground, outside. I 100% know i need to do something before all the renovation as, like you said, 50 years is a long time for an oil burner, and i dont want to do all this construction and THEN have the thing die. I was hoping a wall mounted gas unit would clear me at least 3x4’ AND give me as much hot water as i get now… but im starting to think that i am just dreaming.

One gas conversion company quoted me $20k (with that ”descaler”). My oil company quoted me $7800 for a new cast iron oil burner system. I dont think i can justify 12k more for what might not be much space anyway—although everyone i ask tells me that switching to gas was “the best thing they ever did.”

Maybe reworking the pipe maze can free up a couple of feet….

The thing with gas tankless is that it provides unlimited duration of hot water, but is limited by how fast it can heat water in gallons per minute (GPM).

When we design that for tankless, we look for a 105 F output temp. It doesn't matter if that starts as 120 and gets mixed with cold to make 105 or if it comes out of the water heater at 105. We then look at the temp of the cold water going in. In my area (mid-west) that can be 40F or less in the winter. (I'm assuming similar 40 F water inlet temps for you in the winter.)

So, we have a temp rise of 65 degrees F to get water from 40 to 105. We then use that info in a chart provided by tankless water heater folks (it doesn't vary by brand, just by gas input) or we do the math. That comes down to about 6 gpm for a 200k btu/h unit (the largest residential unit), and again that's only when it's very cold.

You can do your own math on number of uses at same time:

shower 2.5 gpm

Kitchen Sink 2.5 gpm

Tub 4 gpm

Dishwasher 1 gpm

Top loading washer 3 gpm

Bath sink 1 gpm

These are all general estimates.

BTW: Generally speaking, a descaler is totally bogus.

Well said, Stax.

The purveyor of misinformation knows no bounds.

The OP is best advised to get recommendations from local contractors who know her area, what solutions others use, and who could do the work.

@Sandra Plate

You did fine.

I think we got all the relevant issues out on the table. You have a general direction and some specific things to consider. You will note that certain individuals didn't actually contribute anything, but instead sat on the sidelines throwing stones at the ones who did.

I don't know what your schedule is, but I think you are getting a little late in the season for a big overhaul. You could also probably get a better deal in the warmer months when boiler guys aren't so crazy busy. And yes, $20k for a tankless water heater is firmly into the "shyster and opportunist" territory - even for NY.

Making a change from oil to gas, or to high efficiency equipment usually only makes sense when you are replacing the equipment anyway because it's EOL. You need to replace this boiler, so get the facts and make your plan now to re-think your fuel choice, etc. However, don't wait until the boiler fails to do the work. When a furnace, water heater or boiler fails, particularly in winter, people are under the gun to fix it quickly and they usually replace it with similar equipment because they don't have the time to consider other choices. Make your plan now, and then I'd replace this next spring/summer.

One gas conversion company quoted me $20k...

What was included in this quote? Does it include:

• gas line from the street to your laundry room?
• removal of the oil fired boiler and oil storage tank?
• installation of a 90%+ efficiency gas boiler?
• tankless gas hot water heater?
• all required permits?
• parts and labor warranty?

$20K is a lot of money. However the investment could increase the value of your home. If you are spending a lot of money on fuel oil each winter, the return on investment could be shorter than you think. If the domestic hot water is also being converted to gas, then that is additional savings each month. Have you asked PSE&G LI if there is a rebate available to do a gas conversion?

My oil company quoted me $7800 for a new cast iron oil burner system.

Did they explain how many square feet of space would become available?

Is your current washer and dryer sitting side by side? If so have you considered buying a stackable front load washer and dryer to free up some space?

I did a little research on combination boilers. There are boilers which support temperatures up to 185 °F. So it is possible a combination boiler would work with your old baseboard radiators. However this is likely to drive the installation cost even higher.

For some reason, I thought the $20k was for the tankless alone.

The cost of a 90% cast iron gas boiler linked to earlier is about $5k (just the boiler).

Venting is through PVC pipe.

A 200k Tankless heater is about $,1500

So let's say you have $10k in materials.

If that's the case, $20k could be reasonable depending on the complexity of the job (OP's tank is above ground)

If done with a combo boiler, one can be had around $3-4k (verses $6.5k above)

But I would have a lot of reservations about the combo boiler (without the direct experience to back it up). I know that when the return temps go above about 130, the efficiency drops quickly. What I had understood was they don't do well with high temp emitters - even if the specs say they can do it. And a system that age is definitely using high-temp emitters. Perhaps it's just the old timers having a hard time letting go, but the cast iron boilers have the reputation for durability and being the right match for high temp systems. If she goes combo, proceed with caution.

There's the other issue though, and that's whether it's a combo boiler or a gas tankless, The OP has reservations about potentially a 6 gpm max throughput in the winter. That 6 gpm is predicated on 200k btu/h input - so any combo boiler would have to be able to direct 200k btu to the DHW if the OP was able to give on that issue. The truth is that 6 gpm for a worst case is still pretty darn good. Any combo boiler I've seen has DHW prioritization.

And BTW: My gas rates are pretty similar to what I linked to: A similar cost per therm, + $22/month facility charge and about .04 per therm delivery upchage. One hundred therms comes to about $62 all-in.

Thanks, Mike and Jake! The gpm info was very helpful. And yes, Mike, for everything you listed plus a ”water descaler”: 20k. My current oil company who quoted $7800 for new cast iron oil burner told me that there really isnt going to be any reduction of the current boiler/hot water tank space. We’re probably going to get a stacked unit and just deal with the huge reduction of space that the new refrigerator and cabinet will take up. Jake, your caution about having to do this on an emergency basis based on the age of the current unit has concerned me—I dont want to be in that position. It‘s looking like the price of gas conversion is just too pricey for someone trying yo get a new kitchen/laundry/den—shame because a gas tankless wall unit would be awesome for extra space AND for clean fuel AND a new fireplace.

@Sandra Plate

You know your budget - so I'll respect that. But if it were me, there's a snowball's chance in hell that I'd replace that with an oil boiler, even if I had to postpone something else. The conversion opportunity is something that only comes around once every 30-50 years. Getting rid of oil would be a glorious thing.

So, I might convert the boiler to gas now, keep the electric tank water heater and do that if/when I had the money for example. Just be sure to size the gas line for the future water heater. And a hybrid electric heater is still an option that wouldn't save space, but would save a lot of costs over what you have now, and wouldn't have the issues of a gas tankless.

So not that I’ll look you up and yell at you if i dont like it (😂) but for your money: you’d convert 100%

100% I would convert the boiler to gas. Absolutely no question. The totally safe bet would be a condensing cast iron model like the one in the link. That particular brand has a good reputation for boilers in general, but I don't know anything beyond that about that particular boiler.

The water heater is a little different story. It could go tankless if you could be comfortable with that, It could be hybrid electric, or it could be the indirect tank using the boiler. Of those three, the hybrid electric or indirect tank would probably be the least expensive to install and still save you money over the cost of what you have. And the water heater can wait.

Not sure if they’re still doing it, but PSEG offered a home energy analysis, contracted out and free to customers. My sister used iREAP in ’23 and found the conversation and report informative. They'll find leaks and other inefficiencies, and you can talk systems.

I think we are in agreement that your current oil fired boiler needs to be replaced some time within the next few years at a cost of about $7800. For an additional $12,200 you could eliminate the cost of fuel oil and electric hot water heating. I would try to calculate the amount of money you would be saving per year if you spent the additional $12,200. I would not be surprised if the annual savings is $2000 and the return on investment was within 6 years. If the budget is tight you could take out a home equity loan and use the monthly savings to pay it off.