Excessive oil usage

jettaglx91

Sorry if this long story, but Im out of ideas so figured id check online. Summary: roughly 1200sq/ft home, oil furnace with forced air, also have central air with heat pump

So back in early December I ran out of oil what seemed quicker than we should have. Calculated it out to about 4gal/day. In the 10+yrs I've lived at this house its always been about 3gal/day in winter short of extreme scenarios. So called to get the furnace serviced and diagnosed as it had been a couple years, figured it couldn't hurt.

Christmas Eve they serviced it, new filter, nozzle, "tune-up". The tech said there was nothing actually wrong per say but should definitely be running better. We were almost out of oil at this time. Got 100gallons of oil on 12/27, 1/10 we were out of oil again. Thought that's odd, got another 100 gallons, out of oil again on 1/27. Now I panic, do some math and try to wrap my head around how its now over 6gal/day.

Everything seems to be working fine otherwise. Call the place that serviced it, they insist there is nothing they could have done to aversely effect oil usage other then since everything is new, its flowing better, therefore using more oil. To me that makes no sense because if the system is supposedly more efficient how is it using more oil to accomplish the same thing(technically its doing less as we put the t-stat down to 65 from the normal 68 when we started seeing these issues). The offer to have someone come and double check it for only the dispatch fee of $100. Being I have no other option than throwing twice as much money at oil I agree. Of course they find nothing wrong.

Neither the tech of the person I dealt with on the phone could give any explanation a second time other than the using more oil cause its flowing better idea. This obviously seems ridiculous to me because if that was the case why did it never use this much previously after being serviced? Also if that was the cause why would I bother ever getting it serviced since it worked fine and saved me oil usage theoretically.

So now I have talked to two other hvac companies and a friend that used to do hvac for a living before getting a promotion. They all think 6gal/day is definitely excessive for a house/system of our size, especially after just being serviced. A side note to this is the heat pump which runs above 40deg outside as well as a wood stove we have that will easy keep it warm enough to not need to run the furnace at all. During this time of excessive oil consumption there were a couple days over 40deg as well as two weekends of using the wood stove during the day while home, but didn't even include those in the calculation so technically its over 6gal/day usage.

Is there anything I can check/confirm to make sure they didn't screw something up? Im out about $800 in December/January from the extra oil usage, service/cleaning, follow up call, etc. And would love to resolve this before repeating itself in February.

jettaglx91

**Something I forgot, on the second visit the tech did say he adjusted something for air/oxygen inlet. Maybe called a flute or something?

Im from the automotive field so it sounded to me like something that could effect fuel usage but if everything was where it should have been after the first visit what could this have done/changed?

Intplm.

If you have been using the same companies for the past few years. You should be able to get something called a "heating degree days" report. This should come from your oil company and can give you a better idea of your calculated fuel costs.

The other thing you can do.....and this seems to be common sense. Check for any new construction or a window or door open.
I know, I know. I get it. Not the first thing that comes to mind.
I had a customer who complained about the same thing. We went into the house and checked everything.
Found a window in one of the kids rooms open.
After that the fuel consumption went back to normal.

woodrow

does the oil line run under the floor

DZoro

Did any of your techs do a combustion analysis? The analysis is like a health report of your system. If they didn't do the analysis find someone who can. Write down the numbers should be CO%, O2, CO2, draft, excess O2, Efficiency.
Those will tell you how your furnace is, but not how your house is doing as far as keeping the heat that your furnace did produce inside the home.....
D

Leonard

New oil filter can have less restriction and Oil tech might have blown back your oil line from burner back into tank so oil could flow easier, old lines might have sludge in them. But burner nossle GPH size will determine what actual flow is. Kinda like a firehose with a tiny home lawn sprayer nossel at end.

It's been pretty cold and windy lately here in southern NH, I heat 1500 SF of 60 year old house. Last week I burned 8.75 gal/day when outside was 0 degs and windy, usually burn lot less, maybe 4 . Burned 200 gal from Jan 7 to Feb 4. Wind really increases heat loss, especially if your windows and doors leak air. ( I added a hour meter on my burner that I can read daily, so I don't have to estimate between fills)

What part of country are you in?
Is house OLD and, is oil line copper in cement floor?
cement can corrode copper line.
But if you've had same un-usually cold windy weather I've had suspect your numbers are reasonable.


In my house I added hour meter to oil burner to record and chart DAILY oil consumption , (knowing nossel GPH size). If ACCURATELY mark oil tank gauge or stick the tank can compare oil delivered with oil burned, difference might be a leaking oil line. To calibrate my oil gauge I used and read my machinist ruler to 1/64 inch

Intplm.

As some one from the automotive field? You can consider your oil burner to be almost like a carburetor. Adjusted for the correct fuel to air ratios.
There should be an analysis report done from the last described service. It might have been left next to your system. It should look like a cash register receipt. If not. Call your service company and have them provide the one that they should have done and should have left a copy with you.

jettaglx91

Intplm. said:

If you have been using the same companies for the past few years. You should be able to get something called a "heating degree days" report. This should come from your oil company and can give you a better idea of your calculated fuel costs.

The other thing you can do.....and this seems to be common sense. Check for any new construction or a window or door open.
I know, I know. I get it. Not the first thing that comes to mind.
I had a customer who complained about the same thing. We went into the house and checked everything.
Found a window in one of the kids rooms open.
After that the fuel consumption went back to normal.

I will check on that report.

No nothing new in the house, we live in a duplex and no one lives next door currently. That was one of the things I thought of for the initial higher then normal usage, but nothing has changed in the last month to coincide to the abrupt drastic change other then it happening at what seems the same time as the service.

jettaglx91

woodrow said:

does the oil line run under the floor

No its all in the basement, oil tank is literally like 4ft away from the furnace with the line running along the floor/wall

Intplm.

Was some one living next door last year? If so. That part of the duplex was heated? Correct. That wall along your attached neighbors house was worm. Maybe that is the issue. That cold wall that the duplex is attached to?? That unoccupied space might be the culprit.

jettaglx91

DZoro said:

Did any of your techs do a combustion analysis? The analysis is like a health report of your system. If they didn't do the analysis find someone who can. Write down the numbers should be CO%, O2, CO2, draft, excess O2, Efficiency.
Those will tell you how your furnace is, but not how your house is doing as far as keeping the heat that your furnace did produce inside the home.....
D

Only thing he told me was it was running at 85%. He had what looked like a multi-meter with some sort of air probe attached.

Nothing has changed with the house in at least a couple years, specifically not in the last month that coincides with the drastic usage change.

I have a feeling the first place didn't really do a diagnosis(or the tech didn't know how) and just did the cleaning, even though the whole point of the initial call was what appeared to be excessive oil usage. Im thinking of calling another company for the purpose of double checking and diag

Jamie Hall

Do get the burner adjustment report. The change seems a bit excessive for it, but a poorly adjusted burner can change the efficiency quite considerably and perhaps that much.

Also, if possible, check the level in the tank as accurately as you can before a fill -- the gauges are none too good when they work at all, but you may be able to get at least a ball park -- and compare with how much oil is delivered...

Intplm.

Is the oil tank above or below ground ???

jettaglx91

Leonard said:

New oil filter can have less restriction and Oil tech might have blew out your oil line from burner back into tank so oil could flow easier, old lines might have sludge in them. But burner nossle GPH size will determine what actual flow is, long as oil line is not plugged.

It's been pretty cold and windy lately here in NH, I heat 1500 SF of 60 year old house. Burned 8.75 gal/day last week when outside was 0 degs and windy. Burned 200 gal from Jan 7 to Feb 4. The wind really increases heat loss, especially if your windows and doors leak air. ( I have an hour meter on my burner that I can read daily, so I don't have to estimate between fills)

What part of country are you in?
Is house OLD and, is oil line copper in cement floor?
cement can corrode copper line.


In my house I added hour meter to oil burner to record and chart DAILY oil consumption , (knowing nossel GPH size). If ACCURATELY mark oil tank gauge or stick the tank can compare oil delivered with oil burned, difference might be a leaking oil line. To calibrate my oil gauge I used and read my machinist ruler to 1/64 inch

The flow difference would make sense but its been serviced before with no noticeable change in usage after.

Im in PA we had a couple zero degree days but that was just last week after the excessive use during January. I also supplemented those with the wood stove and when we also had a couple abnormally warm days now as well. I would confidently say this January was mild.

Line is copper but its not underground and no leaks.

How/what did you use for an hour gauge? That is a good idea.

Intplm.

jettaglx91 said:

woodrow said:

does the oil line run under the floor

No its all in the basement, oil tank is literally like 4ft away from the furnace with the line running along the floor/wall

Ok sorry . Missed that . Was wondering if you had an oil leak.

When we closed the window ( it had been open a little for a long time, young teenager) the fuel costs dropped. Could also have something to do with the attached neighbors that are not living in the vacant duplex.

jettaglx91

Intplm. said:

Was some one living next door last year? If so. That part of the duplex was heated? Correct. That wall along your attached neighbors house was worm. Maybe that is the issue. That cold wall that the duplex is attached to?? That unoccupied space might be the culprit.

Yes someone was living there the previous 10+yrs we lived here, that was what I thought contributed to the initial extra usage, but the huge jump in January is what concerns me. Substantially more than ever before.

jettaglx91

Jamie Hall said:

Do get the burner adjustment report. The change seems a bit excessive for it, but a poorly adjusted burner can change the efficiency quite considerably and perhaps that much.

Also, if possible, check the level in the tank as accurately as you can before a fill -- the gauges are none too good when they work at all, but you may be able to get at least a ball park -- and compare with how much oil is delivered...

Im pretty sure I didn't get any specific report like you and others have mentioned, I will check the paper work but sounds like that should be a given based on a standard cleaning/service?

Yea I figured the gauge/float was meh at best for judging it. I calculated it by literally running out of oil, adding 100 metered gallons, and repeat. Only difference being my manually adding 10 gallons in between running out at delivery the next day. That would actually make the gal/day worse but didn't even count that as it was a fairly small amount.

jettaglx91

First off THANK YOU guys for tall this feedback, was crossing my fingers to get a reply, definitely wasn't expecting this many responses.

Bringing up again the tech mentioned on the second visit he said he closed something about an air/oxygen inlet almost all the way. Does this sound like anything familiar? Any idea what he did? If so would it effect oil usage?

Reason I ask is if everything was "fine" why did he make this change?


Also he had mention something about the pressure or 140psi. Doing research I just found that my burner is supposed to run 100psi. Obviously I imagine this would use extra oil. Is that something normally checked/tested or was he just throwing out numbers to try and explain stuff?

Intplm.

Ok....so to reiterate. The things he is talking about, and you are quoting can all be addressed from a proper burner adjustment report......And ask them to give you a before and after adjustment report.
Sounds like they did not use the proper tools to do this service.

As to the "air to oxygen " comment. Sounds like an air band adjustment on the burner.
Again. Back to the adjustment report. This should tell you what you need.

jettaglx91

Ok cool ill follow up on that report and "report" back

Leonard

jettaglx91--- pickd up hour meters in yard sale, Cramer Type 635C, 120VAC. Conveniently they were already mounted in steel box. I added fuses. Box has previous owner's labels (water heater and steam) , but I wired it into burner and circulator.

Problem is I got burner power at aquastat, not after primary stack temp safty, was easier that night. So when it runs out of oil, meter keeps running. Have to re-wire it across main burner motor so meter will stop when out of oil. And use armored hi-temp cable for wiring.

My oil nossel is 1.1 GPH so 100 hours = 110 gallons

Mechanical mount of box to lolly column is unusual, VERY tight thick coat hanger steel wire. But that box doesn't move at all even if you wack it. So it's structurally sound. Note steel wire is wrapped twice around lolly column, that's why it doesn't move.

Leonard

I calibrated Scully brand gauge on my 60 year old 275 gal oil tank, every night measured burner hours and gauge marker's distance from top of gauge with accurate machinst's ruler. Plotted up daily gallons usage VS tank gauge level in Excell over 3 fillups.

Was SURPRISED at how linear and repeatable MY gauge was. As gets empty float hangs in air and can start to see that as curve flattens out at top of graph. Your gauge may vary. Pics of plot and my oil gauge attached.

Also plot of last years daily fuel use, gaps in plot were I didn't take data. Note how much day to day usage varies, I measured accurate to 1/10 gal

STEVEusaPA

I think it’s been colder than usual, and the attached house is empty, unheated. You’re losing a lot of heat to that party wall.
I’d lean more toward that, although all the service issues would’ve had me switch companies.

SuperTech

There's no way in hell that I would charge a customer an additional service call fee for a call back on a tune up that my company performed.

You need to find out what burner nozzle the technician installed, did he replace the old one with a new nozzle that is the same size? You also need to see if the nozzle matches the manufacturers specifications.
A change in nozzle size, pump pressure and air/fuel ratio can all affect fuel consumption. I always record what the pump pressure and vacuum measurements are on my invoice. As well as Stack temperature, %O2, PPM CO, %CO2, draft over fire and draft in the breech and cad cell resistance reading. This information should all be on your invoice to ensure you that your tune up is correct and the equipment is operating safely, reliable and efficient.

jettaglx91

All I received was the invoice and the attached inspection report. Definitely not all the info you guys are asking for

GBart

If you live in a duplex the wall that connects the two was not counted in the heat load calculation for sizing your equipment, if there isn't any heat there now or it's low that wall becomes a load and heat will be moving out of your side into that, especially if they didn't insulate, this could dramatically increase your usage by 1/3 or more.

Leonard

Likely not the cause but noticed you said pump was making 140 psi. Don't have lot of experience but I thought standard pressure was 100psi.

Suppose tech could compensate for that by adding more air flow,
Result might be furnace will shut off sooner. Maybe slightly less efficient combustion, but not 2X consumption.

------------------------------------------------

My bet is your house's heat loss changed, Maybe: air duct in cold attic/cellar sprung a leak, kitchen or bathroom exhaust vent to outside is stuck open, or weather stripping around outside door got loose or dried up and broke off, common wall with neighbor is now cold.

My 1-st apt was on 2nd floor, was new construction and electric heat. Found I could shut off my heat when gone during day and weekends and it wouldn't cool down much ..... heated by losses from 1-st floor apt's ceiling.

Harold

I am also suspicious of the unheated wall.

You can buy pretty inexpensive infrared heat sensors. And it may include a physical sensor on a wire. Which can be handy. The IR detector can get confused by reflections. Not so the wired heat sensor. If nothing else; try Harbor Freight.

Get one and start searching the common wall. Both for wall surface temperatures and possibly air leaks between you and the unheated side of the duplex. Any penetrations. Electrical boxes that penetrate the wall because it is easier when you are building. Same for any penetration (water, ducts, any uninsulated penetrations). Compare numbers from your other insulated walls with the other duplex common wall.

And when you are finished with that; you have a nice tool to check your windows and other possible infiltration on your side external walls.

jettaglx91

GBart said:

If you live in a duplex the wall that connects the two was not counted in the heat load calculation for sizing your equipment, if there isn't any heat there now or it's low that wall becomes a load and heat will be moving out of your side into that, especially if they didn't insulate, this could dramatically increase your usage by 1/3 or more.

The other half isn't new construction, its a completed house that is insulated and been lived in before, just not currently.

jettaglx91

I could see the house being empty next door making some difference but seems way to coincidental the big jump was after being serviced.

Side note there is no open windows or open/leaking duct work or vents

Intplm.

Have you checked the vacant area.. Even if there is no opening to the outside next door. The place is not being used and heated now. Right?
Thats most likely the reason for the difference in use.

DZoro

Has it been vacant all winter or just recently?
D

Leonard

Dumb question...... are there any open or broke windows next door? Airing it out , tree branch fell and broke it maybe. Real estate agent left a door ajar and wind blew it open.

Any chance oil guy delivered your oil to neighbor's tank?

Very unlikely but suppose you could measure your tank with a stick to see that you got all the oil you paid for. But think an oil guy would be VERY stupid to shortchange you 50% , that's REAL EASY to notice. Plus around here the truck meters print the gallons delivered on receit and state inspects and seals the meters.

jettaglx91

DZoro said:

Has it been vacant all winter or just recently?
D

It has been vacant since October '17 if I remember correctly. No noticeable increase in oil usage last winter

SuperTech

> @jettaglx91 said:
> Has it been vacant all winter or just recently?
> D
>
>
> It has been vacant since October '17 if I remember correctly. No noticeable increase in oil usage last winter

Is it possible that it was heated last year and now maybe the tank is empty and the owner won't fill it until he has a tenant. I'd ask if the vacant area has been winterized. It just seems likely that something like that or a mix up with the oil delivery is to blame. Maybe the oil guy delivered next door by mistake?

Gordy

141000 btus x 5 gal = 705000 btus a day minus an efficiency of 80% that is about 564,000 btus to the house. 1200 sf that's about 20 btus a sf. The op is supplementing with a wood burner also.....

Must be keeping the other 1/2 pretty darn cold.

May I ask about the wood burner? Do you use it more than usual in the past? Is it of a decent efficiency?

The air to fuel the wood burner has to come from somewhere which brings in outside unconditioned air.

The only way to put more precise numbers to all this is to do a heat loss on your home. I highly doubt the shared wall of the duplex is not insulated, usually its insulated for sound deadening. Anything is possible though.

Gordy

On a side note the nozzle is .75 gpm that would mean your furnace burner would be on over 6.5 hours a day on average.

jettaglx91

Leonard said:

Dumb question...... are there any open or broke windows next door? Airing it out , tree branch fell and broke it maybe. Real estate agent left a door ajar and wind blew it open.

Any chance oil guy delivered your oil to neighbor's tank?

Very unlikely but suppose you could measure your tank with a stick to see that you got all the oil you paid for. But think an oil guy would be VERY stupid to shortchange you 50% , that's REAL EASY to notice. Plus around here the truck meters print the gallons delivered on receit and state inspects and seals the meters.

I checked last week and didn't see anything.

Nah we check our tank after a delivery and it def was delivered

Gordy

Also what is your geographic location?

Leonard

I remember as a kid I built fires in fireplace in fall, drew so much air rest of house was cold. Fire was nice, but it likely increase overall oil consumption.

Wood stoves are likely better WHEN running, but have to leave flue open ALL night. Draws warm air out of house in wee hours of the night, as coals are bearly burning and even later have gone out.

Gordy

It felt warm by the fireplace.....