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Need to change Oil Fired Hot Water Heater...LP or Oil?


My brain hurts...So I have an Arrow Oil fired Hot water heater with a Lennox forced air furnance in my 3000 sqft home. As there seems to be problems in the Middle East each year and the growing oil demand in China and India, I was wondering what I should do in little steps.

So since my Hot water heater is on its way out, I thought maybe I should move to LP (natural gas is not an option in the northeast where I live) I understand that Oil have about 15% more BTU's per gallon but also costs more. Today the spot price is $3.69 and LP was about $3.10.

I was looking into a Toyotomi on demand oil fired hot water heater and also something from Rinnai for on demand LP.

If I started to move to LP, the Hot water heater would be first. The furnance was installed about 3 years ago by the previous owner. So its still new.

2nd question. Does anybody use pellet furnance's. I saw one from Harman. I have a pellet stove insert and it seem to work well. We went through about 3 Tons of pellets this year.

Any help would be great, I fell like I keep getting conflicting information on all this stuff. Even the energy.gov sites I've been to are no help.

Thanks for reading,



  • btanoue
    btanoue Member Posts: 5
    Bock vs Arrow


    Thank you for the btu clarification. I didn't know it was such a large difference.

    I measured the incomming water temperature in the dead of winter and it was 42-45F.

    I've heard for oil-fired that Bock is good.

    Something like a marketing phrase of "Turbo Flue".

    I know that when the person measured the temperature out of the exhaust it was about 400F. He said it was very high compared to a Bock because more heat gets absorbed by the water.

    I can just replace the tank above the burner? I didn't know that.

    Also the tank kinda peculates (spelling, like an old coffee pot).

    Would a newer tank be as efficient as the Bock?

    Sorry, I'm really new at this.

  • billtwocase
    billtwocase Member Posts: 2,385
    I gotta agree

    with SLO. I would get a packaged unit, and i have had good results with John Wood center flue. Bock is also a good tank, but a little pricey. I have also replaced Aero water heater. Bradford-White now owns that line, so it can still be had. Plus is using the same burner. Not that i am a fan of Aero burners, but they work OK in water heater situations. 
  • btanoue
    btanoue Member Posts: 5
    Last few Questions of Tankless vs Oil Fired.

    OK, so I'll call my oil company and ask them to only change the tank with a Bock, Bradfordwhite, or John Wood. I'll install what ever they feel more comfortable installing.

    OK, so one last time just to make sure.

    The LP gas based on demand by Rinnai is not really that good an idea for my 2.5 bath home (one of the baths is a deep tub) right.

    My home does not have access to natural gas.

    The water temp was about 45F in the dead of winter (check with a meat thermometer :)

    The only reason I am asking is because every time I call a plumber I keep getting the "Go LP" its cheaper and more efficient. Is this just marketing?

    The other benefit I hear is that I don't need a service contract because the Rinnai basically is trouble free for years...Since I don't know anybody that has one, I have no idea if its true.

    Also I did check and LP tank is $60/year and gas is $2.80/gallon.

    For oil I'm in a contract for $2.98/gal and the spot is $3.69

    I'm sorry I'm asking again. Its kinda big decision for us.


  • Mark Eatherton
    Mark Eatherton Member Posts: 5,853
    A bucket full of BTU's, is....

    a bucket full of BTU's. The only thing that changes is the COST per btu, and the efficiency in converting it from it's native form to its' thermal energy form.

    So, there are 90,000 btu's per gallon for LP, and it is CURRENTLY costing $2.80/gallon, so $ divided by BTU X 100,000 = $3.11 per therm (100,000 btu's).

    Oil is roughly $3.35 per gallon (currently), hence $3.35/120,000 * 100,000 = $2.79 per therm.

    The efficiency of the appliance must ALSO be taken into consideration...

    Oil typically is limited to the mid 80's for efficiency. The LP system can go as high as 94%. So the NET cost per therm for these two products, assuming the given efficiencies would be as follows;

    LP = $3.11/ .94 (efficiency) = $3.30 per net delivered therm (not including tank rental).

    Oil = $2.79 / .83 = $3.36 per net delivered therm.

    The other efficiency that has to be taken into consideration is the seasonal efficiency, and that is dictated by the appliance manufacturer. Tanks are less efficient than tankless heaters, but SHOULD be taken into consideration in the grand scheme of things.

    So, at present, the base cost of operating on oil is only slightly more than that of LP. However, and this is a BIG however, the price of both commodities is extremely volatile. Every time another riot breaks out in the middle East oil rich country, the price of ALL petroleum products jump. No one knows for sure what the future holds. Don't forget to take the annual seasonal efficiency of the appliance into consideration.


    There was an error rendering this rich post.

  • btanoue
    btanoue Member Posts: 5
    Guess its easier to stay with Oil.


    Thank You.

    I wasn't sure how to do the math because I didn't really understand the units. I guess its simpler to just stick with oil and only manage one fuel.

  • Jean-David Beyer
    Jean-David Beyer Member Posts: 2,666
    stick with oil

    One of the costs of staying with oil is the cost of the oil tank. In about 1980, my old oil tank was leaking, so I had it replaced for in the neighborhood of $1000. At the time, the cost of a tank was about the same irrespective of size; i.e., it was mostly labor, overhead, and profit. At the time I was using 600 to 700 gallons per year, so I got a nominal 1000 gallon tank. Here, they had to be buried. It seemed to me as though that size was a good idea because I could fill it during the summer when the prices were likely to be lower, and because the delivery trucks would have an easier time of making deliveries when there was less snow on the ground.

    30 years later, I figured out the tank was likely to need replacement, although there did not seem to be any water in the oil. I had decided to go with gas, but the gas company would not run gas to my house unless I got rid of the tank. The State of New Jersey really wanted to get rid of in-ground oil tanks, and gave a rebate of up to $1000 (I think it was) towards the removal of tanks, so I had it taken out. Unfortunately, you might say, I had a competent contractor do that, and he tested the tank and the surrounding soil for evidence of leaks, and there was a small leak. Water did not get in, but some oil got out. There was about a year of delay while my two insurance companies battled it out, with the tank sitting in my yard. It has been there, now, almost two years. One insurance company decided to pay nothing, and the other only a small amount. In my case, that leaves me with a cost of almost $50,000 to pay for remediation. The State of NJ makes grants to pay for remediation, but with the budget problems and the large number of removed tanks needing remediation, there is about an 18 month delay in processing grant requests. And a request cannot be submitted until the insurance companies have come up with the amount they will pay.

    It seems to me you can buy a lot of gas for $50,000, even if you get your oil for free. If you use oil, you better have a way of knowing when your tank will leak, and replace it a year or two before it happens.
  • btanoue
    btanoue Member Posts: 5
    Tank Removed prior to move in with Hydro carbon test


    Thats an excellent point. I think I should be OK. The previous owner had one in ground and then had it removed. They did the hydrocarbon test a number of years ago and left me with the documentation. Everything passed. I have a newer tank in my basement now and it seems like its not leaking. I think today I'll call me oil company about replacing the hot water heater tank.
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