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Switching to natural gas heating system

I live in PA and presently have an oil furnace. My house is over 100 years old and still rely on the radiators to supply heat. I am paying a great deal of money annually to heat my house using oil. My furnace is maintained regularly. I am considering switching to natural gas and would like to hear opinions or suggestions moving forward. I already have a gas line coming into my home to supply gas to a gas oven.

Re: Switching to natural gas heating system

kking, From the descriptions in your post, you have a boiler there, not a furnace; most boilers don't have to be removed, & can simply be fitted with a new burner that uses natural gas instead of oil for approx $2500---this should include the permit cost the contractor has to obtain from the town; some jurisdictions may authorize only the gas co. to do all phases of the conversion; local code may require a gas line size of at least 3/4" or 1".

You're lucky you already have a gas line coming into your home; in most cases a conversion is much more feasible than if there was no gas service in your area, or the gas co. had to open up the street to install a gas line (which often takes months) to your house at the cost of approx. $800.

Your best bet is to consult the Yellow Pages under "Heating Contractors" and "Oils-Fuel" and read the display ads to find a heating contractor that specializes in OIL TO GAS CONVERSIONS & who has done a number of these over the years---get at least 2 or 3 estimates from different local contractors & written quotes as to the cost of the job.

Be prepared to give the prospective oil-to-gas conversion contractor information as to whether it will be economical to you to do the conversion; factors to consider are 1) the age of your present oil-fired boiler---if it's relatively new, and properly sized to the size of the house & highly efficient, it's possible that you may not get the money return by doing a conversion; if the boiler is 10 yrs old or more, it's probably a candidate for either a new gas boiler, or an OIL TO GAS CONVERSION gas burner---this would be the less expensive by far, & is done by leaving the existing boiler & all its piping in place, & removing only the old oil burner assembly from the boiler & inserting a similar-looking new burner that uses natural gas instead of oil; I would recommend the Carlin Model EZ-GAS because I have direct experience with them & they are reliable; Carlin is a well-know company that has been around for many years; 2) what is your annual cost of heating oil plus annual cleanings, & service calls for the oil-fired equipment????---and how will that compare with the cost of a gas-fired boiler---gas-fired boilers require much less maintenance & emit much less soot than oil, so the only usual maintenance with a gas unit is an annual inspection & a light cleaning, if needed----so there will be a savings on maintenance; 3) the present cost of natural gas in most areas remains much lower than the cost of #2 fuel oil, and has remained so in recent years---but that could change---you or your conversion contractor should be able to calculate how much you spent for oil & maintenance in the past year, compared to what you will spend going forward for natural gas for a year----the calculation requires you to compare the price of a gallon of #2 fuel oil (140,000 BTU of heat) with the price for an equivalent amount of burned natural gas (also in BTUs of heat)(1 cubic ft gas=1020 BTU/1 therm= 100,000 BTU) so that you can come up with an accurate cost comparison between the 2 fuels (plus the higher oil-fired maintenance costs)---- Google "fuel oil vs natural gas cost comparison calculations" to get a good idea of the amount you'll save with natural gas.

Be aware that the natural gas conversion burners have an efficiency of approx 70%, while the efficiency of a brand new gas-fired boiler (which would cost much more than a conversion kit) is approx 80% to 90% (thus burning much less fuel), so if you stay in the house for 10 more years or longer, a new gas-fired boiler might be considered.

Often overlooked by homeowners considering a conversion is what is the status of your exterior wall insulation, and do you have relatively new double-pane storm windows---many homes have a serious heat loss in winter months because there is no insulation blown into the exterior wall cavities of the house (see Yellow Pages under "Insulation"), thus, they burn a lot of oil or gas because the heating system can't keep up with the heat produced by the radiators going right through the leaky walls & drafty windows----the Insulation contractor can come over the house & check the insulation & tightness of the windows---if needed they work from the outside, take a small piece of siding off here & there,drill a small hole & blow in the insulation to fill up the wall cavities for a few hundred $$$---this is the best energy-saving deal available; any single-pane, cracked or drafty windows should be immediately replaced with double pane vinyls.

So one strategy you might follow if you need exterior wall insulation & new windows, is to delay the gas conversion until you can get the exterior walls nice & tight & the windows nice & tight, and THEN do the oil-to gas conversion.

Re: Switching to natural gas heating system

Generally its only cost effective to make the switch when the old equipment needs replacement.

Unless you have spare money laying around not doing anything.....

Re: Switching to natural gas heating system

dodsworth and Houston Remodler Thank you for the reply.
You offer some great information. My cost annually for all oil, service and maintenance is in the neighborhood of $6,000. My boiler is about 20 years old. I am considering an insert and/or brand new gas system. As part of this process, we will be looking at insulation, which I know is a problem in my house. I have already started replacing all windows. I am hearing very different things about the effectiveness of the insulation blown from outside into walls. Any other additional information on this may help.

Thanks again!

Re: Switching to natural gas heating system


By all means go for the blown-in cellulose insulation!

Along with the new windows, it's known in the HVAC trade as "closing the envelope"---the idea being that the heated (or cooled by summer AC) air molecules will have a much tougher time getting thru the walls & windows once they're produced by the radiators (or the AC), thus the oil or gas boiler (or AC) won't have to come on so often & you save fuel & electricity---the thickness of the exterior wall blown-in insulation is typically R19, which is recommended; also required in the attic is a thick blanket of blown-in or blanket insulation---R40 required---you can view these different insulation R-values if you visit the insulation dept. in the home improvement stores---each piece of insulation has its R-value stamped on the outer covering.

Before I converted to gas, I was able to reduce oil fuel usage from 1200 gal./heating season to 700 gal. in the Mass. area, and my AC bills went down as well---that's a 42% drop in the heating bill alone just by doing the blown-in insulation project.

How many gallons of oil (or therms of gas) you save depends on several factors; the size of the house in total sq.ft., the amount of insulation, your general location in Pa., the size of your boiler, etc.---do you get zero degree weather quite often in winter (any sub-zero?); what is the total sq.footage of the house you have to heat (including basement/boiler room); do you have any "zones" in your hot water piping, or is it several floors with a single hw pipe snaking to all the rads in the system?

What is the BTU output & BTU input of your boiler?---this can be usually seen on the face tag at the front of the boiler; also the boiler brand name & model # ---it is a common occurrence that the previous owner or boiler man installed a boiler that's TOO BIG for the heating needs of the house---which means it will waste $$$ by burning oil that's designed for a larger house--- thus we can compute the BTU heating needs for your house if you provide the info requested---it's often possible to run the boiler with a SMALLER FUEL NOZZLE than the one that's on there now----thus if you have a fuel nozzle on the burner that is rated at 1 1/2 gallons per hour (this value is stamped on the face of the nozzle), it may be possible to DE-RATE the oil burner nozzle down to 1 gph, or even 3/4 gph---ask your service person if he feels comfortable doing this----this procedure would require that the service person use a COMBUSTION ANALYZER to monitor the burner flame as he maintains minimum flame smoke/soot as he downsizes to a smaller nozzle opening, as much as is allowable; this procedure would reduce the amount of oil that's burned per heating cycle & extend the amount of time the boiler fires during a heating cycle---this almost always means less oil burned over a heating season, especially if the boiler is over-fired with an oil nozzle that's too large for the heating needs of the house.

Cast iron rads, btw, are in my humble opinion far better & more efficient than some of the more recent options--be glad that you have them---once they get hot they STAY hot for much longer periods, & thus are more efficient than baseboards & other less efficient convectors---they also emit radiant as well as convective heat---can't be beat.

Believe me, any added insulation & new windows will cut your oil bill in half, and it will also allow you to keep the house cool in the summer (so air conditioning costs should also be halved)----not only that, but once it's in the walls it stays there & will reduce your heating & AC costs season after season for as long as you live in that particular house

Re: Switching to natural gas heating system

I am reading about Air Krete blown in foam insulation. I am considering this for walls. Thoughts? Sounds new but very promising. THanks!

Re: Switching to natural gas heating system

We converted last year from a 1940 oil boiler to a Buderus GC 124 gas boiler, which is designed for gas conversions. Efficiency is rated at .84, so its better than average, but not high efficiency. As a conversion unit it has piping connections and other features that make the conversion easier. We were able to reuse the flue and just downsize it to the smaller flue of the new unit. The actual burner is the size of an extra-tall 2 drawer file cabinet, so it is much smaller than the oil boiler.

We converted about 2 months after buying the house, so we don't know about previous heating costs. However, we did consult with our realtor and other owners (located in Alexandria, VA), and all agreed that oil costs were quite high. The new boiler is compact, quiet, and seems to be very efficient.

I also have a gas water heater, dryer and range, and I think my highest monthly gas bill was only about $100-110. The conversion cost about $8400, but this is an expensive area and all bids we got were in the same price range. The price included removing the old oil tank from the basement, which was not an easy task, and they had to extend the gas line to make the connections for the new boiler.


Re: Switching to natural gas heating system

Thanks, Bruce.

Anyone out there hear about Air Krete blown in insulation?

Thank you!

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