With the “Fracking Effect” of plentiful, relatively inexpensive natural gas upon us, there is a heating system conversion rush from oil, and justifiably so. However, this rush borders as all rushes do on becoming foolhardy. It’s an easy sale to “play the numbers”, telling the customer what they want to hear. The typical scenario is an immediate “boiler swap” with perhaps a less than ideal economic resultant. But there are alternatives, depending upon your particular circumstance.

If you are fortunate to have immediate access to natural gas and your existing oil-fired system is “old enough to vote”, the choice is obvious — swap it! However if you have a newer oil system and it performs well except for the fuel bill, you have options. Similarly, if you live in a non-natural gas area and are using propane, you also have options.

Let us review these potential scenarios.

Firstly we must qualify your natural gas source AND it’s actual, delivered cost to you.

Please refer to our additional, related Blogs from our site library for more detail. We will highlight these as we proceed, but cannot currently hyperlink them.

If you do not have natural gas access currently in the building, solicit and qualify its cost.

  1. If it’s on your street the line extension may in fact be free as an incentive by your provider.
  2. If it’s down the street a ways there likely is a significant service extension cost up front. There may also be group incentives to extend and supply a neighborhood. This cost must be amortized over some service period. “Run the numbers.”
  3. Natural Gas (like Electricity) is a Distributed Fuel. As you know on your Electric Bill, the Kilowatt-Hour cost is burdened with service and distribution charges. Natural Gas is the same. Solicit an ESTIMATED GAS BILL from your provider!

Read our blog “USING A ‘HEATING COST CALCULATOR’ — CAREFULLY!” ….. For more detail.

NOTE: We harp on using a “Heating Cost Calculator” for any project. “Gotta know where you are before you know where you’re goin’.”


Natural Gas (and Propane) Boilers (FHW) and Furnaces (FHA) are available in very different flavors, technically and efficiency-wise. The EPA assigned AFUE (Annual Fuel Utilization Efficiency) Rating can vary from the minimum required value of 85% to over 97% on Weil-McLain Products as an example. AFUE Rating must be obviously considered when making an economic decision.

Scenario 1: Older Oil Boiler (15 years or more), NatGas available at site, longer planned occupancy/ownership. A “no-brainer”. Replace with the highest efficiency unit available and enjoy the benefits.

Scenario 2: Newer Oil Boiler (under 10 years?), otherwise same as Scenario 1. Consider upgrading your Gun Burner alone. Yes, there are several manufacturers of very high efficiency Gas Conversion Gun Burners. Among them:

  1. Carlin Combustion Technology Option 1 and Option 2.
  2. Wayne Combustion Systems Several Options.
  3. Midco International Residential Series.
  4. Additional Domestic and Foreign Suppliers.

However, you must make an objective judgment as to the viability of this conversion. As an example the Weil-McLain Gold Series Oil Boiler has been around since 1995, still available and produced in quantity. It is an older “two-pass” design, 85% efficiency, with tight heat exchanger passages. A good candidate as are similar competitors’ models.

A Gas Conversion Gun will be higher in combustion efficiency (up to 95%+?). Combined with the oil boiler that is efficiency-limited by oil’s chemical composition should provide you with very respectable boiler performance. We have no means of estimating this, but certainly the Gas Gun Manufacturer should have some history as a marketing tool. Ask.

To expand our point, we regularly scour Craigslist for Gold Series Oil FHW and Steam Boilers as budget upgrades in our area (NH). We can save several thousand dollars by obtaining a well cared for unit for sometimes just above scrap value. Haven’t bought a lemon yet.


Scenario 3: What about a LP (Propane) Conversion? The Fuel Cost Premium in our view has relegated propane to a “fuel of choice”. As of this writing, Propane is a 22% premium over #2 Fuel Oil regionally. Otherwise the outlines in the prior Scenarios apply.

Subsequently propane is primarily used for cooking, drying and seasonal or supplemental heating along with a wood system in our rural area.

There is however an option that may be available to the propane user. Gas tanks are usually owned by the fuel dealer, locking the customer into the supplier. Conversely, oil tanks are owned by the customer and provide sourcing flexibility.

Commercial and particularly industrial propane clients typically own their storage tanks and contract with suppliers. There is no reason not to own your own tank, save two reservations:

  1. The initial cost of the tank and its installation.
  2. The manufacturing date stamping of the tank, the subsequent re-testing and re-qualification requirements. Tanks are date stamped (Mo.-Yr.) and must be re-qualified ten (10) years after manufacture. (If you buy a used tank, check the date stamp! Don’t buy a dying or worse a dead horse.)

We have a local tank-owner client who advised us of a recent propane buy at an astounding price! He shopped aggressively and paid C.O.D. His purchase price was well below that of the equivalent fuel oil.

So, you off-the-gas-pipeline gas users may have some hope yet. Check it out.

In closing, propane has historically been a premium-costed fuel, being as high as 65% until the recent pressure upon oil pricing. Having said this, it is conceivable that we may see a variant of natural gas emerge as a pressurized or liquefied fuel to challenge propane. Stay tuned …