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Thread: OT - Oil Furnace Tune Up
11-29-2011, 12:02 PM #1
OT - Oil Furnace Tune Up
Any tips on tuning up a Beckett oil furnace - Air intake adjust, damper, stack control, electric eye cleaning?
11-29-2011, 12:07 PM #2
11-29-2011, 12:55 PM #3
Don't forget the fuel-oil filter.
11-29-2011, 01:03 PM #4
oil burner tune up
Start by changing the filter on the tank. That's where most delivery problems occur. If your burner was recently tuned by an oil burner technician then he should have adjusted the mixture settings to run at peak efficiency. Don't mess with the mixture! There are 2 ignitors in the gun of the barrel. Remove the unit that holds these and file the ends clean and adjust the gap. Sometimes a burner out of adjustment will have a build up of unburned oil (sludge) and only one ingniter will fire. Remove the fuel nozzle and replace with an exact replacement. That's all you need to do besides draining the low water cut off valve.
11-29-2011, 01:34 PM #5
Pretty much like most air rotor type burners. Flip the transformer open and undo the oil pump tube from the burner gun assy. Work it out and remove nozzle. Spray angle, hollow or solid and GPH will be stamped on hex. Buy the same thing. Usually 90% of the problem. Clean burner tube. If you take the porcelained electrodes out, recall the exact electrode angle and gap. Or buy a cheap plastic electrode gage. I clean everything with carb cleaner. If the gun has an air spinner, make sure it's clean. Unplug the fire eye/cad cell and clean with cloth, only. There may be a primary and secondary air intake. The primary is a shutter vertical and next to the pump. The secondary will be an air band wraping around the housing. Make sure they're clean. With the sec. band closed and prim. open is how you begin correct combustion air. The flame should come on after the air is out of the gun. You may get a puff back so keep your face away. The flame should have slight tips of flame coming off the main burn. If there's an impingment plate at the back end of the firepot the flame should be almost be touching it. A firebrick or blanket job should be further away. There should be a slight roar to the burn. The best advice is to replace the nozzle and filter once a year. Like I ''should'' do. When you look at the gun and notice the electrodes are back behind the spray pattern, you may wonder how the oil ignites. The 10,000 volt transformer makes a strong spark. The air rotor blows the spark into a horseshoe and into the spray.
Last edited by Ray Behner; 11-30-2011 at 03:38 AM. Reason: changed GPM to GPH. That'd be a BIG nozzle!
11-29-2011, 01:44 PM #6
Clean the flue gas passages etc etc etc, no so good having an efficient burner if the the heat transfer surfaces are clagged up.
PS It can be a really shitty job, because a lot of burner service guys don't bother to do it.
PS2 If it was mucky, the burner should be reset because flue and firebox conditions will be different annd can effect Co2 and smoke readings etc etc.
PS3 Don't forget to check the air inlet side of the burner,....... they can be dust and fluff magnets causing all sorts of combustion problems.
11-29-2011, 01:51 PM #7
Good addditions, Limy. To be professionally done, I used to check everything.
Flue draft, over fire draft, CO2, pump pressure, stack breech temp., smoke sampling. Complex and time consuming. Oh yeah, stinky and filthy, too.
11-29-2011, 01:57 PM #8
11-29-2011, 02:35 PM #9
Thanks for the info, I'm also tryng a 20% mix of filtered hydraulic oil. Hey a filter is cheap the oil is free & I hope to save a couple 100.
11-29-2011, 05:59 PM #10
Becketts are a bit fussy about electrode position, and give you little slack for bending or realigning worn ones, but if you buy new electrodes they should come with a little aluminum setting gauge.
In some past thread about technological marvels, I nominated the oil burner nozzle. It's an amazing bit of precision machining, calibrated to the hundredth of a gallon per hour, and you can get a new one for 7 bucks. Worth doing annually.
11-29-2011, 08:25 PM #11
I have a Peerless 155000 BTU/Hr water boiler. It is only really used to heat domestic hot water, as wood provides 98% of our winter time heat.
The Beckett AFG burner sounds like a fighter on take off when it kicks in. After burner slam and everything.
The unit came with an extra nozzle which I believe is a size smaller than the one fitted.
Will there be any "convenience" i.e. sound reduction, to fitting such a nozzle? Other benefits? I don't need the btus, in fact, the burner short cycles from time to time.
All comments welcome!
11-29-2011, 11:00 PM #12
That's a hell of a lot of heat. You should be in at least a 3,000 SF house with "average" insulation, from 20 or 30 years ago, to require that. Should be a 1.25 nozzle to get that, 1.25 GPH of oil consumption, about 4.25 per hour of burn time.
Short cycle is inefficient. At 0*F, a furnace should be firing at least 90% of the time,else it is over fired. I heat a 1900 SF house with a 43 thou gross, 36 thou BTU net boiler. Lowest I remember is minus 13*F, and no problem.
I sold and installed lots of furnaces back a few years. It is so goddamned EASY for furnace salesmen to over sell. Hey, the higher the BTU, the higher the price, right?
In most cases, with an oil furnace, it is just the capacity of the nozzle that is the difference, firebox is the same size, heated area is the same.
Were it my home,I would try a .75 nozzle, and if that was insufficient, a .85, or whatever you actually require.
How big and how old IS your house?
Sorry I missed that it is just to hot up bath water. I don't know what to say! Stupid!. Normal water heater is about 45 thou BTU. It hink you are over fired.
11-30-2011, 03:35 AM #13
You're right, George. That's a very wastful way to only heat water. On the other hand, an oil fired w/h is quite efficient. The initial cost is scary, but boy do they heat water. They should be serviced more often than a furnace, due to the small flue passage and that puny little .40 or .50 gph nozzle. When they get dirt of goo in them, you get a bad burn resulting in a possible sooting problem. Which then plugs the flue in the heater.
11-30-2011, 06:39 AM #14
Cal, it sounds like you've got a HW boiler with a tankless heater for your domestic hot water installed in the boiler. I assume the tankless is piped in series with a regular electric hot water heater so you're not running the boiler for domestic water heating during times when there's no heat requirement for the house itself?
If so, my advice is to cut the boiler off and let the electric water heater do its thing year round. Tankless heaters are unbelievably wasteful, and the larger the boiler the more wasteful they are when used primarily for domestic water heating.
The typical HW boiler / tankless combination uses a different control than a boiler without the tankless. The standard control will normally be set up such that the boiler will only run if there's a call for heat from a t'stat within the space. The tankless control will run the boiler to maintain the water temp even when there's no call for space heat, resulting in a lot of unnecessary oil being burned.
Most of the typical boiler/tankless setups were installed back when heating oil was 30 cents per gallon, or less. Made sense then, but not today when oil costs 10X that much.
My house was built in 74, and had a boiler with a tankless when I bought it in 85. House construction and insulation is average for the mid 70's. Tankless in series with electric heater. After a couple years, I rewired the control so that the boiler didn't run unless there was a call for space heat, and that change alone cut my oil usage by 1/3. I replaced the boiler in the early 90's and didn't buy a tankless with the new one. Just tied the inlet and outlet piping for the other tankless together such that the domestic water passed on by and on to the electric HW heater. Even though all my domestic water heating was now being done by the electric heater year round, I didn't see any significant increase in the annual electric bill.
My dad was in the heating business for 40 years and is a mechanical engineer. He did industrial, commercial, and institutional work exclusively. I've heard him say numerous times that he's never seen an oil fired boiler in actual use that would run an overall efficiency better than 65% even though the stated efficiency would be in the 80% range. With a little soot to insulate the heat exchanger surfaces, the overall efficiency can easily drop to 50% or less. Short cycling will soot up a boiler pretty fast even when the burner is properly adjusted.
If you figure the cost per btu of oil, and then figure you're wasting 1/3 to 1/2 of every gallon, it becomes quickly obvious that you'd have to have really cheap oil, or really expensive electricity, to justify heating domestic HW with a tankless heater in an oil fired boiler.
11-30-2011, 08:24 AM #15
I typed up a long version , but cyber rodents must have gotten to it.
The domestic hot water is on the priority loop with it's own circulator. The big heat exchanger equipped holding tank sits next to the boiler. There is a second loop for a radiant thin slab with ceramic tile finish floor in the kitchen dining area. It only comes on early morning under control of an air temp T-stat.
The burner label says .65-1.65 gph burn rate. The spare nozzle is 1.1 gph
I'll check with Peerless to see what is the smallest nozzle recommended.
I appreciate all the comments
Last edited by CalG; 11-30-2011 at 01:59 PM.
11-30-2011, 09:20 AM #16
And I thought it was nuts when the boiler service guy replaces the nozzle every year.
Maybe cheap insurance....
My boiler fires maybe 80 percent of the time when it's at the lowest temperature
we see around this region of NY - maybe minus 10 F or thereabouts.
11-30-2011, 01:45 PM #17
Well, That was easy
Replaced the 1.25 nozzle with the 1.10 nozzle. Vacuumed out the flame box and iron work.
Maladjusted ;-) the air controls and set the t-stat on the radiant slab so it's calling for heat.
The sound of the burner "might" be a bit less, The kick-in is certainly a bit less explosive.
I downloaded the Beckett product information. Pretty simple devices all in all.
What are symptoms of "too much air"? High flue temps and heat up the chimney?
If I recall, 435F at the outlet of the boiler was the target. Seems high....
The heat shield that sits just in front of the nozzle was quite clean with only slight signs of fuel dribble build up. Everything back of the nozzle had a fur coat made of lint and dust however. Shop Vac to the rescue.
Now if I only knew what a well adjusted flame looks like...
11-30-2011, 03:15 PM #18
Some of the noise on stqrting may have to do with electrode adjustment and air flow, but there seem to be some furnace and flue combinations that simply don't start without a boom. My mom had a problem for years with this, and nothing solved it until they installed an oil delay valve. This allows the burner fan to come on and establish a little draft, and the electrodes to start sparking for a few seconds before oil gets to the nozzle. It solved the problem of a booming start and banging the draft regulator every time.
11-30-2011, 11:10 PM #19
As I mentioned, I have been out of the business for a while, BUT, there are tools that any oil heat contractor NEEDS to have.
A pyrometer to check stack temp, a O2 sensor to check for excessive combustion air, a smoke detector, and I forget what they are called, you suck smoke thru a filter and compare to a pattern, darker the color, the less clean combustion you have.
I still have a Firerite, I think it is called, where you suck in 10 squishes of combustion product. It causes the solution to increase on a scale to tell you how much excess O2 you have, I think. Been years, 30 or so, I'm sure that electronic devices do at least as well, today.
ALWAYS have your oil furnace properly cleaned, and I do NOT mean call the guy and let him do his thing. You have surface area in there that WILL make pounds of scale that look like the stuff your kids play with, that stuff you glue together, sulfur flakes, and they WILL fill up the heat exchanger .
I old and installed the same brand as my cousin had, and he told me he had it serviced every year, since 1959. Got "Not from this build up a new guy to check it out, "You NEVER had it cleaned?" "Every year!" "Not from THIS build up!"
Hand holes that had never been opened to clean out. Few KNOW how to clean an oil furnace. Vac the area, replace the nozzle, the filter, gimme a couple hundred bucks.
Them should be driven out of the "business". Scams are too prevalent.
12-01-2011, 03:41 AM #20