To buy or not to buy an oil burner?
OK, so I’m new to this forum but would greatly appreciate any help.
The setup:
My house is a split ranch with a finished basement on one side and my home office (I’m a therapist who works from home) on the other. Upstairs I have 3 mini splits (2 in the bedroom area – each about 9000 BTU) and one 18000 BTU in the living room, dining room and kitchen. We have an open floor plan so the one in the living room and bedrooms heat the whole house. I’ve gone through two winters (last one was pretty cold) and the splits kept the house at 71-72 degrees. I also have 2 mini splits downstairs in my office – one for the waiting room and one for my office. I ran the oil heat once in the winter during an especially cold night so the pipes wouldn’t freeze.
I have a wood stove insert in the downstairs finished basement part that I use on the weekends. We had that installed 2 years ago with a new high efficiency lining. I can get the downstairs pretty toasty if I want to (90 degrees).
As backup I have oil heat. We moved in 2 years ago and had the oil tank replaced. Last year I had the burner replaced. Last year as well I got an indirect water heater which has helped greatly with burning less oil.
I use the mini-splits as my main source of heat. They are great and are cheaper than the oil. I have two chimneys. One for the wood stove and one for the oil furnace. When I was having the chimneys swept they said my liner for the oil heat is in bad condition and would need to be replaced. About $2000. My oil boiler is from the 1980’s with 82% efficiency. There is a hole in the side of it (insulation coming out from a rusted area) that looks to be more cosmetic than anything. Although what do I know. When I have it cleaned each year the guys says that the “internals” are still good.
My question: Should I replace the oil boiler? Won’t it eventually go on me being so old? I don’t know if going from 82% efficiency to 86% is worth it, if I’m basically using it to heat my hot water and on the occasional cold night. BUT, if they are going to replace the liner, should I get the boiler replaced too? I’m thinking the diameter of the liner might need to be smaller if I get a new boiler. Although I could be wrong in that. So wouldn’t it be better to replace the whole thing at once. We don’t have gas on our street, so that’s not an option. I can go through the mass save program and get a 0% loan. It’s just hard to justify spending $6,000 on something that I rarely use. Is there anything else I could do? Something I’m not thinking about. Or should I just bite the bullet. Thanks in advance.
John
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Replies
Propane condensing hot water tank that can do the heat when you rarely ask it to.
http://www.htproducts.com/versahydro.html
Pioneer boiler just a boiler, since you have an indirect tank is $3-4,000 for the unit.
Triangle Tube Prestige for a modcon LP tankless boiler same cost around $3-4,000
Buy a low cost tankless water heater and use it as a boiler.... $1,000 and up....
The condensing units rid you of your flue.
You could also buy another oil boiler for only double the cost of a new gun...
John,
It's helpful to post a reference to where you are on the climate zone map as that will very often be a very big factor in the advice people dispense.
My two cents based on what you've described is that it's up to you...
If you feel like you can get away without the oil boiler then get rid of it (FYI, I'm in the same boat as you right now heating with oil, and gas is not an option).
You might consider spending the same money adding insulation to your attic or chasing down drafts if it's possible/hasn't been done already.
AJ BUILDER -
Thank you for the quick response. I tried to research your answers but got a little confused.
1. It sounds like you're saying to switch to propane instead of keeping oil? Is that an expensive endeavor? Don't you have to have a propane tank installed, buried, etc. We just got a new oil tank 2 years ago. It seems like a waste to not use the oil tank.
So I would buy a tankless water heater (propane) and use that as a more "backup" heat for the really cold nights? (Is that the Triangle Tube Prestige one you suggested?)
I don't know how much new guns cost? Are you saying that would be a cheaper alternative to the propane one? I don't mind spending money here because I envision us being in the house for a long time. (20-30 years). I just want something that's not "overkill" as I'm only using it to heat the hot water and periodically the house.
Hi Lucas -
Whoops. I live in the Northeast (Boston). Zone 5a. I don't know how I would get rid of my oil burner as I need something to heat my hot water, correct? We just got a new indirect hot water heater last year that runs off the oil boiler. We actually got the attic insulated ... so the house seems pretty air tight.
If you just need the oil for hot water, just get an electric water heater. Using a boiler for hot water only is inefficient, especially in the warmer months. As Lucas said, spend the $5k you saved by skipping the boiler on air sealing or insulation and maybe you could shut off a minisplit or two.
If the power goes out, so does the boiler, so I assume the only "backup" the boiler provides is the rare extremely cold night when you worry about the pipes freezing. You c would almost certainly remedy that without a new boiler.
Since your primary use for the boiler is to heat hot water, and it's going to take a couple grand to make the flue safe & legal, you could just get rid of the oil system entirely and install an electric (or heat pump) hot water heater.
The cost of heating hot water with a high mass oil boiler (any efficiency) is higher than heating with a standard electric HW heater, due to the excess standby losses. If you were using the boiler for actually heating the house the standby loss would be apportioned to both hot water and space heating, making the hot water portion roughly comparable to an electric HW heater at average MA rates. But instead, that standby loss is offsetting the load on your mini-splits with expensive heating oil, which is about 1.5-2x the cost (at this year's lower prices) than heating with mini-splits (at this winter's higher prices.)
Propane is even higher cost per BTU than oil, but the efficiency of a condensing tankless would be about 85% (much lower than it's steady state 95%+, but still not bad) compared to the boiler heating hot water at ~40-50% thermal efficiency. A better class propane tank heater like HTP's water heaters & combis will do better than a tankless if you go with the smallest burner versions. (The Phoenix Light Duty is relatively new, but probably has enough output to cover your hot water load, and cost about $2000 + installation. It's also combi-capable if you want to run it as your backup system too, but it takes a heat exchanger and some hydronic design- it'll likely be at least 10 grand by the time you're really done there.)
Oil boilers can survive for quite a long time as long as they aren't being abused by too-low return water temp. A legitimate combustion efficiency test performed by a qualified tech would tell you where it's steady state efficiency is. By the time it's 30 years old an 82% efficiency unit will have fallen off some, but it could still be north of 75%. If you're not really using it for space heating you'll never make up the installed cost of new 86-90% efficiency oil boiler on fuel savings. But if you don't really need it for spacing you may find the cost of running an electric hot water heater comparable, cheaper up front than fixing the flue, and you may be better off just mothballing the oil system (or installing an electric boiler in it's stead, if you really need it for backup.)
What its the BTU in/out of your existing boiler, how many zones, and what type of radiation?
The efficiency of using an oil boiler just for hot water is pretty poor, so that's another factor in addition to all the others people have pointed out pointing to using an electric or heat pump water heater.
ok thanks guys .. I will look over the posts tonight in greater detail. I have little time right now. It looks like the consensus is to get an electric one (even though I just got a new indirect water heater last winter). So with an electric water heater I'll be able to heat the house in cold cold days??
I just realized too. I paid $900 for them to sweep the chimney, put a cleanup door and a cap on top ... If I go with electric I'll loose that money too
Before buying ANYTHING you need to do more analysis.
A standard electric hotwater heater probably won't be enough to heat your house, even if it were legal to set it up as a combi unit in MA (which it isn't.).
A properly sized electric BOILER is pretty cheap up front, and would still be able to use the indirect and zone controls. But it depends a bit on whether the existing electric service is big enough to use that way. You probably have enough juice to power it, but we don't know that without more information.
The oil boiler's output is probably 2-3x oversized for your actual heat load, but what are those numbers?
The amount & type of radiation that you have can also help guesstimate the size of electric boiler that works. The amount of radiation relative to the load also affects the operating temp of the system, and there are some limits there too, but if it's capable of heating the house with an oil boiler, it should work just fine with an electric boiler.
To do it "right" would require calculating the heat load on a room-by-room basis using ACCA Manual-J methods, but a down & dirty I=B=R method spreadsheet calc is almost as good, good enough for sizing an electric boiler. If you want me to walk you through an I=B=R calc, give me your zip code (for outside design temp), and give me an accurate description of your wall construction, window U-factors (or description), and attic insulation etc.
A typical 2000' raised ranch in eastern MA will have a heat load between 30-40,000 BTU/hr, but there are exceptions on both the high and the low side of that. You're probably looking at a 10-12kw electric boiler, which needs a dedicated 50amp 240V circuit. The upfront cost for a 12kw boiler is about $1500 (internet store pricing.) You can probably use the same zone controls as the oil burner, but you may or may not be able to use the same pump for the boiler loop- it depends a bit on how the system is configured. There is very little thermal mass to the electric boiler compared to an oil boiler, and even if it short-cycles a bit on zone calls it's not an efficiency or wear & tear disaster. Your "priority zone" would still be the indirect HW heater, and it would deliver about the same recovery rate as a standalone standard 40 gallon propane tank heater.
You may be able to sell the oil in the tank, and maybe the tank too, if it's pretty new.
Heating hot water with a heat pump water heater is cheaper than heating it with an electric boiler, but a heat pump water heater can't run your "backup" heating system. If you are a showering family you can get a reasonable rate of return on a drainwater heat exchanger on a large chunk of vertical drain downstream of the shower(s), but that has to be assessed on it's own merits, and doesn't affect the installation of an electric boiler as the replacement for the.oil boiler.
In mass there is no point at which propane is cheaper than oil
An electric boiler? This aint Colorado. Electric rates are about to go well over 20 cents per kwh, which in round numbers means the parity with oil went from over 5 per gallon to over 7. I will take the oil thanks
Get a second opinion on the flue, oil burners don;t tend to beat them up AFAIK,
If your boiler can be set up to cold start, it would be more efficient for hot water.
How many gallons of oil do you burn a year?
If you are just running it to keep the heat pipes from freezing,well, that is the answer isn;t it..
Get a hot water heater of your liking and let the scrap man have the boiler.
electric boiler is ridiculous in my opinion..... a new water heater and give up on the hydronic....is an option....
An LP unit that pipes with PVC for exhaust solves many issues.
Dana, the heat load is almost totally carried by mini splits. The oil system for heat could be tiny to just back up the tiny miss that the mini splits can't cover.
Dana, you are the numbers guy... figure that the replacement boiler could be just heat pulled from a replacement LP unit or a direct vent oil unit could work and avoid the flue reline.
Direct vent oil, smallest water heater unit, would heat your water, use your new oil tank, not use the bad flue, could be tapped to add some heat to old hydronic runs, done.
Not a great solution but I bet the home is rather large... Dana... so we still need to know the BTU rating of the boiler and the sqft of the home.
One thing about my posts being wrong or bad guesses..is...it gets us closer...to... what's right.
Let's get this puppy figured out and put to bed.
You guys are awesome.
I thought I posted but I can't find it. My home is 2000 sq ft. Raised ranch I had the attic insulted 2 years ago. I have 3 zones. Kitchen/living room/dining room; 3 bedrooms upstairs/bathroom; and one half of my downstairs (I have a wood stove down there and will be putting in another mini split). So all I really need is 2-3 days a year to call the heat, but that's really so the heating pipes down't freeze. The mini splits do an unbelievable job at heating.
It looks like now either a direct vent oil or an LP.
IS this all that you need? I attached a picture to this posting of what I found on my boiler downstairs.I don't know if that helps with finding out the BTU output of it.
THanks!
attachment
The rationale for the electric boiler is...
That it's a system he doesn't actually USE for heating the house, except at a backup or at temps below the 95% temperature bin. Installing one is comparable in cost to fixing the aging oil-burner system that he currently isn't using for space heating, but still needs for domestic hot water, but it's annual maintenance is effectively ZERO.
The oil boiler can probably be nursed along for another decade, maybe two decades as a funky hot water heater, but only after dropping 2 grand on a flue liner, and another couple-three hundred every year or two on burner maintenance, flue cleaning etc. And it may fail next year, precipitating the need to come up with another option anyway. An electric boiler should be maintenance free for at least couple of decades, maybe forever at the duty cycle John is running and if it fails, just replace it.
A new oil boiler is going to cost the better part of ten grand, but with an electric boiler you'd be out for less than five, maybe even less than three. And since it's being used primarily hot water, the operating cost won't be any cheaper than an electric boiler.
Heating hot water with the electric boiler at 25 cents/kwh is not more expensive than heating it with a high-mass oil boiler that isn't being used for anything but hot water. This is due to the fact that the standby loss and idling power of the electric boiler is a tiny fraction of that of an oil boiler. A boiler that's running 82% combustion efficiency will average maybe 40% (on a good day) efficiency when all it is doing is serving an indirect HW heater. See system #2 in Table 2 on the attached Brookhaven Nat'l Labs testing report. (and Appendix 2 at the end.) For a bunch of money you could install a super high efficiency heat purging oil boiler and get higher hot water heating efficiency, but you'd never make up the difference in operating cost if you're only using it for space heat for 25 hours/year, and at a very low duty cycle even on those days.
Having electric heat backup for heat pump systems is common, and it's fine, as long as it's backup, and not the primary heat source.
It's not clear that this house would be code-legal with just the mini-splits for space heating, since for the heating system to meet code it needs to be able to heat EVERY room to 68F at the 99% outside design temp. An appropriately sized electric boiler would meet that code requirement using the existing radiation.
If I'm reading the nozzle spec on the combustion test tag correctly, this unit burns 0.85 gallons per hour. At 82% combustion efficiency and 138,000 BTU/gallon that 0.85 gal./hr x 138,000 BTU/gal. x 0.82= 96,000 BTU/hr, serving a total load that's probably more like 30,000-40,000 even if it were the ONLY heat source. (Without a better description of the house & insulation we can't make that call.) The last thing you want to do is replace it with an electric boiler of equal output (28 kilowatts, which would be over 100 amps at 240V), since that would likely require an electrical panel upgrade. Sizing the boiler correctly to the load is key to keeping the installed cost well bounded.
A 2000' 2x4 framed raised ranch with some air sealing and insulation upgrades with clear glass double-pane windows will usually have a heat load of 15 BTU per square foot @ a design temp of +5F (a handful of degrees colder than Boston's 99% bin) give or take. The more of the lower level that is below grade, the lower it will be. If it's almost all above-grade and you have a lot of window area it could hit 40K, but probably not. It's still worth running both a I=B=R spreadsheet based on the construction U-factors as a sanity check rather than just punting with a 12kw (40,000 BTU/hr) boiler, since you may be nearing the limits of your electrical service capacity.
It's also worth measuring up the size of all the radiation (by zone, if you're hell bent on a fossil burner solution.)
Lochinvar CDN040 (propane) . 9 to 37K output . Hook it up to your IDWH and your heat , get a smallish Lp tank and get on with your life . It is also my opinion that maintenance is required on any heat source which has a heat exchanger or element . The exchanger does not care how the heat was made , only that the same water at the same temp entered and left the exchanger , The theory that the same thing will not occur in both heat exchangers or to electric resistance elements is ludicrous . Heat exchangers can be maintained , elements must be changed when necessary .
How much fuel oil is purchased per year is a relevant question that Dana should be crunching......?
No electric boiler for me, but admit it is an option.... one could even do it with an electric tankless using the circ on site. I favor my ideas ...I like Richards.... he is in the area and could do the work too I imagine.
Myself I will never install oil. If electric a basic 40 gallon electric with good insulation. Best feature is that it limits shower times automatically via running out of hot water. There will be no hour showers.
I do see the future of new homes going electric and natural gas and rural economy using pellet stoves and chopping wood for a woodstove...
John M, oil use per year is?
A propane fired mod-con is a VERY expensive "backup" solution, more expensive than a new oil boiler, and it would have comparable or even higher operating cost at MA style oil & propane prices:
http://www.mass.gov/eea/energy-utilities-clean-tech/home-auto-fuel-price-info/propane-price-surveys.html
http://www.mass.gov/eea/energy-utilities-clean-tech/home-auto-fuel-price-info/heating-oil-price-surveys.html
Low volume users (like him) would typically be paying north of $4/gallon for propane in a local market averaging $3/gallon for average volume users. (I know people who were paying $5 last year.)
This boiler is used maybe 25 hours per year AT MOST for space heating. He's really looking for means of heating domestic hot water, with at least some ability for space heating. Marring a mod-con to an indirect he might see 60% efficiency in water-heating mode (see System # 11 in the Brookhaven testing report). At 60% efficiency (in a 95%+ efficiency boiler he's getting ~55,000 BTU/ gallon out of the propane into the hot water.
At an optimistic $3.50/gallon that would be $63 / MMBTU for the heat that ended up in the water. At a more likely $4 for low-volume users, its more like $72 / MMBTU.
A code minimum 0.90 EF electric hot water heater delivers 3070 BTU/kwh. At 25 cents/kwh that's $81/MMBTU. At 20 cents it's $65/MMBTU. It's really the same range, but the installed cost of a cheap electric tank will be more than 10 grand under the installed cost a mod-con.
The hot-water-only heating efficiency of an electric boiler + indirect will be slightly less than a standalone electric hot water heater, call it $100/MMBTU for hot-water heating only, but it's going to be more than 5 grand cheaper to install.
I'll leave it as an exercise to John to run the water heating cost numbers on a oil boiler at ~40-50% efficiency- it's more expensive than heating hot water with an electric tank a 25cents/kwh.
And you don't really HAVE to pay 20+ cents/kwh.
In Massachusetts the electric utilities are "decoupled", and you have the option to choose a different supplier than the local utility who does the billing and maintains the distribution grid. If you're paying 20+ cent/kwh, there are MANY cheaper options (even 100% renewable options) from other parties that are substantially cheaper than the NStar or National Grid standard rates. You still pay the fixed charges for the grid, but the energy portion has ballooned to 2/3 of the bill or higher for most people in eastern MA. You can get 100% wind power on a 3 year contract with one vendor at about 12 cents, compared to NStar & Nat'l Grid's new-improved ~16 cent fixed rate electricity. There are even cheaper options if you'll accept higher-carb sources. Solar lease options from multiple solar companies are available at 16 cents (which includes the grid costs, since it's net-metered), for homeowners who will allow a solar company to put it on their roof. Just because the rates got boosted into the stratosphere this winter doesn't mean you have to roll over and pay them, and if you're heating your house with mini-splits there is no time like the present to explore other options.
Down the list of other issues, an electric boiler or electric hot water heater would even a lower-carbon emissions solution than oil at the ISO-NE average grid mix, and could be made effectively near-zero carb if you're willing to buy your power from a 100% renewables vendor.
Going forward even the standard grid-mix is going to see year-on-year lower carbon, due to the policy support by the region's state governments for carbon reductions in the power generating sector, not just the EPA mandated reductions.
Hey guys, thanks for all the answers. You seem to put a tremendous amount of effort in trying to solve my problem. I had a thought: by my calculations the last time I filled up my oil tank was April 2014 and I still have a quarter of a tank left. By my calculations I spend about $50-$55 a month heating my hot water. I'm assuming that electric boiler might cost me $40-$45 in electricity to heat the water. In this case I'm really only saving $10. Maybe in the long run this may payout but it doesn't seem like that much of a savings. I've already invested $900 in adding a cleanout trap in my chimney as well as a cap, so I already feel like I'm going in that direction. From what I've read and learned if you take care of your oil burner and have it yearly cleaned it can last a long time. Correct? So right now all I'm spending is $2000 for my new chimney liner. I can progressively save up for a new oil boiler in the next few years. I'm also assuming that my boiler might last longer because I'm only using it for heating my hot water and the occasional very cold night in the winter. I really love my mini splits and it continues to amaze me that they can generate heat when there is seemingly very little of it outside. Thanks. Thoughts?
IIt's not the $10/month savings. It's the annual maintenance saving plus the savings up front for avoiding the cost of a new liner. Going to an electric boiler means no annual servicing, no flue inspections, no combustion checks & re-jetting. It's just reliably there- it works until it doesn't, but most would run several decades if used only as the backup heat and heating hot water with the indirect. You're probably averaging something like $300/year on system maintenance issues between burner tune ups and flue checks, etc. and with a boiler that old you'll probably be into some control parts replacement etc soon even if the main boiler hangs on for awhile. That's another $25/month in avoided cost.
Heating with oil has no economic future, despite the current drop in oil pricing. The oil glut will fade as Europe regains economic footing, and Asian demand continues to increase. The US oil production increase are going to reverse themselves at $60/bbl pricing, since it costs more than that to produce much of the shale oil, and those wells are good for only about 2 years of reasonable production, and at the end of year 3 they've delivered 95% of all the oil they ever will produce. As demand picks up the price will rebound. It's unlikely that electric cars will be deployed SO quickly worldwide that the price of oil will remain low for a decade or more. We may get a couple of years of $3/gallon heating oil out of the current glut, but expect it to be followed by $5/gallon heating oil within the next decade. (I'd love to be wrong on that, but that's the view from many analysts in the banking sector, the folks who dictate the financing costs of drilling.) Tight oil drilling permits were down by more than 40% as of November. I expect the December numbers to show further declines. Some of those already-drilled and pumping projects will never break even unless the price bumps north of $120/bbl- they are quite literally going broke, but the sunk costs are already down the frack-hole, the best they can do is keep pumping until they can't, to minimize the loss. (I have a relative in the oil & gas exploration biz, who may have to be moving soon if the prices don't pick up.)
Even if you fix the liner and hang with the old girl until she croaks, the LAST thing you want to do is buy another oil boiler to use primarily as a water heater. Even a cheap pretty good cast iron boiler like a Biasi B-series it would cost more than $5K to install (unless you're REALLY up for the DIY on an oil boiler, and have a licensed contractor that would let you do it under their license.) A high efficiency oil boiler would run you closer to $10K. Any oil boiler has the annual upkeep nuisance in addition to it's fuel use costs (did I say that often enough yet? :-) ) An electric boiler should run $3-4K ($5K if you're getting gouged) up front, and you could still use your indirect with it, and requires no maintenance to speak of.
Seriously, price out what it would cost to install a 10-12,000 watt electric boiler before throwing money at a flue liner. You can probably mothball the old boiler in place and plumb the electric boiler in parallel with it (with isolating ball valves) if you for some reason think that oil might be going back to $1.50/gallon again during your tenure at this location, in which it might pay for itself in 20 years.
Don't let the fact that you just spent $900 on the chimney draw you into pouring another $2K down that hole on the gamble that the boiler will last forever, and that oil will remain this cheap forever. Neither of those gambles seem very likely to this observer. YMMV. If you have reasonable roof pitches for solar you can already get substantial discounts from your electricity rates on electricity for $0 down. (SolarCity is going to be offering 4%-30 year money for rooftop systems in MA starting in 2015. That includes monitoring maintenance plus warranty for 30 years. That would be even cheaper power than the $0 down lease deals, which are already at a big discount from utility rates.)
Okay guys, so I had another idea that might be even more efficient. What if I went ahead and priced out an electric boiler simply as backed up because I want my house to be up to code. I think someone said at this thread that my boiler needs to heat each room up to 68° in order to be code. What about a heat pump water heater? I would put it in the finished part of my basement in the boiler room. I have to have a dehumidifier running 24 seven anyways down in that part of the basement (in the summer) because it's partially underground, about 3 feet or so. The basement in the winter gets down to about 45 or 50° but I'm figuring that will be offset by the hot summer months to heat the hot water. I had thought about putting a mini split downstairs in that part of the basement but if I put a heat pump water heater down there I don't think I would need one? I also have my woodstove on that part of the room so if need be on really cold nights I could run the wood stove for heat for the heat pump. So my ultimate goal would be to have an electric boiler that I almost never use, and just need for back up for the heat that my minisplits system supply to the house. And then a hot water heat pump. I know I would have to have a drain for the condensate. I think I could rig up a pump that would pump to the next room that has a drain for my washing machine. My wife and I are not planning on having kids and we on;y have 1.5 bathrooms. I would think our domestic hotter needs are minimum and a heat pump water heater would be ok for demand.
Dana I thought a lot about your comments about the maintenance of an oil boiler. That with flu cleanings and any regular maintenance on my boiler would be $300 or $400 a year. As well as the cost of a new liner. I know I just got a new high efficient indirect water heater last year, but maybe I can sell that for some money. I also don't want to spend $2000 on a new liner for my chimney. If I go all electric than I'll never have to worry about the chimney again.
Thoughts?
I didn't read every word in this thread, but I see no justification for ANY further investment in oil equipment. Whatever was spent on the chimney was wasted. Get an electric water heater. Use the mini splits as primary heat, since you have 5 of them. Use the woodstove for more heat.
edit: electric OR heat pump water heater.
Hi David, yes thanks for the advice. I'm starting to realize that electric is the way to go. The most recent thing I had proposed in my last post was whether the best case scenario of getting a heat pump water heater in combination with an electric boiler is the best solution for me. Reference my last post. Thoughts?
Dana - Is there a way to private message you? I had a question/request for you and didn't want to keep taking up the thread. I think the thread helped greatly in the direction that I needed.