Converting from oil to natural gas boiler
I have reached the end-of-the-line on my ~25 year old oil fired hot water heating system. Since I have a gas line for the stove and hot water heater, I can chose to replace my defunct unit with either a new oil unit, or with a gas boiler (I also have a ductless central AC/heat pump system that is 2 years old). At present, I am leaning towards converting to gas, for the following reasons: 1. I think that a gas boiler will be more reliable and require less maintenance than an oil unit (my oil service contract is currently $200/year). 2. NG has been cheaper in my area of PA (currently ~1.07/ccf vs $2.76 gallon). I use about 800 gallons of oil/year, so this is about $1,100/year difference). 3. Finding reliable oil dealers in my area is becoming a bigger problem. There has been a lot of consolidation in the past 5 years, and both pricing and service has been a struggle for me and my neighbors. I have an existing chimney, but it would probably need to be relined were I to go that route. A few questions: Would I be better off with a conventional vent (chimney) gas boiler (80% efficient) or direct vent high efficiency unit (95%). The latter is more expensive (but would qualify for a tax break). What about overall reliability? The chimney vented system seems simpler, does that translate into better? Any thoughts about manufacturers? Utica, Peerless, others? I would probably think of replacing my 13 year old gas water heater at the same time… any reason to consider a tankless hot water heater? Pluses/minuses? Thanks. -g
Replies
My knowledge in this area is limited enough to not try to answer all your questions, but can hit on a couple.
Pricing on fuels is volatile and not always competitive equally. But I believe that use of gas is increasing and should increase. We can take that from underground and not be sending dollars overseas for the energy. gas is also far cleaner for the enviroment
But to do dollar comnparison of fuelcost, you need to be comparing cost per BTU, not feet to gallon to pound.
I would go to the gas boiler and gas domestic hot water myself.
For deciding instant on th water, you should ask plumbers in your area. Mine refuse to install them, because out water is heavy in mineral and the build up inside the things quickly means complaints and service calls
Thanks Piffin. BTW, the cost comparison was made by energy content. The estimated cost in NG (1,080 ccf, $1220) was the equivalent of 800 gallons of #2 fuel oil ($2300).
I just did it last year. I replaced a 35 year old oil fired boiler with a Weil-McLain Ultra nat gas unit. (Southern York Co. PA) My heating bill was cut in half and then some. Use an indirect-fired storage tank for domestic hot water.
A 95% condensing unit will cost almost 4 grand more, and won't save that much more in gas, BUT... a conventional unit will require a stainless steel chimney liner, a condensing unit can be vented with PVC plastic. (Much cheaper) Add in the tax credit and it's almost a wash. Save money by disposing of the old boiler and oil tank yourself.
Brands are comparable, it's the installer that counts. Make sure you can get service and parts for the unit you choose. Others can suggest their favorite make. You won't be sorry.
Thanks R. Have you had any problems or maintenance issues with the direct venting?
1) Less maintenance is right. You'd pocket the better part of that $200 a year with gas.
2) Per MBtu, you are paying maybe $28 now ... max. w/ gas would be about $13 - your heating bill would drop to less than half.
3) no comment - oil is largely foreign purchased and somewhat more polluting (an expert may say a LOT more polluting).
3+ if you can afford a condensing furnace and enjoy the tax credit, that would be great. I think the HE condensing furnace should be reliable, I think they have good warranties available. The HE will save an additional maybe 10% over the medium efficiency ... maybe more depending on configuration. You'dl save that on the life of the unit (say 20 years). You should have enough to do the math, now.
Don't go tankless to save energy if your lifestyle/use of hot water is about average. A tankless may save over your old water heater, but so will a tank style. Tankless MAY require larger gas pipe. ... your new furnace may also. Double check w/ e.g. gas company or BO to make sure you have no surprises or that it would be easy to upgrade.
Maybe consider a combined water heater/space heater and install a hot water coil in your current air distribution system (pull the furnace out) ... talk to your HVAC contractor about that. This would consolidate heating and hot water into one piece of equipment.
Don't forget about your A/C .... now might be the time to put that back into your central distribution system.
Thanks Clewless- I'll look at
Thanks Clewless- I'll look at the tank systems a bit more closely. My central AC is a ductless system with heat pump, and only about 2 years old, and pretty high efficiency.
So your heat pump doesn't
So your heat pump doesn't make heat? Only makes cold air for a/c?
No, the heat pump will heat per spec. The house is 80 years old with a hot water cast iron radiator system- 2 zones- the kitchen and everywhere else. I had the ductless AC/heat pump installed 2 years ago, as retrofitting a ducted AC system would have been very difficult (the house is 3 stories, so the second floor would have been a problem). Each room is its own zone, with a separate controller.
The problem with the heat pump alone as a heater is as the temperature drops blow 30 degrees, the efficiency of the single stage heat pump declines pretty steeply. Thus the best way to ensure comfort and minimize cost is to use the hot water system to heat the whole house to about 60 degrees, and then use the heat pump to adjust the temperature in individual rooms that are in use, leaving others at the colder ambient temp (~60).