Only 81% efficient

Jay Oxley

a bit costly isn't it.

John_11

I just had my boiler of 2 months old looked at for the efficiency and it was only 81%. I am having a meeting with my contractor and see if he can put something in that is not a paper weight that holds water. I am wondering if you can give me a hand on how I can calculate the running cost difference between this boiler and a good one. What I want and/or should have is a cold start boiler. I have a boiler mate to heat my domestic hot water and my house is a 1350 sf ranch.

For calculation numbers we can estimate I will burn 1000 gal of oil per year.

What should an efficient boiler efficiency be?


Thanks
John

Roland_13

Efficient Boiler

Hi John,

What equipment are you running now? It is possible that the heating plant was not adjusted properly after installation. You probably have the ability to remedy this cheaper and easier than buying a new boiler. Did you or your contractor do a heat loss calculation? Where do you live?

There are people on this board who can give you excellent advice on how to remedy your situation

John_11

I am running a "cold start" (so they say) boiler Utica - Starfire III Water Series Boiler, Model: SFH3100W. I think the BTU output for this boiler is about 117000. It has a Taco SR506 Control. This is a 6 zone switching relay and the aquastat is a Honeywell L8148A1124 (supplied by boiler manufacturer). I have all separate circulators for each zone. The AFUE rating for this unit is 81%. The heating for the house is hot water baseboard. The boilermate is an Amtrol Mod #WH412 41gal.

I just had my heating company look at it to do the efficiency test and that was as good as they could get it. My stack temp is about 550 deg, he said it was high but he could not get it down anymore. He got the efficacy to 81% and that was what the manufacturer said is was going to be as well.

Heat loss calculation on the house...no should I calculate those numbers? I live in Maine and this house is less than 3 months old. Standard 2x6 exterior wall construction, batt insulation in walls and ceiling, Andersen windows through out.

Thank you

Robert O'Brien

There

is an alternate lower firing rate for that boiler that will increase efficiency substantially.The lower rate has a DOE of 79K Btu/Hr. Specs on the lower rate are in the I&O manual.If you have an EXP Taco relay,add a PC 700 reset control.If you don't have an EXP, I would use a Tekmar or Honeywell full featured ODR control.

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John_11

I guess I will have to do a heat loss calcuation on the house to see if I can run the boiler at 79k?

Robert O'Brien

I'd

be shocked if the heatloss was greater than that.Look under the resources tab above for software

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UniR_3

Highly unlikely

It would be highly unlikely that at 1350 sf 79 MBH gross or net won't keep up... if it can't, your best investment would be in better insulation and reduced infiltration.

Robert O'Brien

5 zones?

of baseboard in 1350 sq/ft? The zone synchronization feature of the AQ 2000 would be a big help!

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John_11

I have 3 zones on the first floor. Kids bedroom on left side of house, kitchen, living and dining zone in the middle of the house and master bedroom zone on the right side of the house. The 4th zone is for the hot water and the 5th is for future basement heat (not hooked up right now)

What is a AQ 2000?

Robert O'Brien

An outdoor reset control

http://customer.honeywell.com/honeywell/ProductInfo.aspx/AQ2514B2

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R Mannino

It costs more if you don't get it.

maine rick

i installed last week an american standered triple pass boiler and i got 88.4% eff. and finished one today and got 89.1% eff. nice cold start boiler to put in. next week doing another one.where about in maine are you?

Roland_15

81% Boiler

Hi John,
You have a new house with good windows so presumably it's a fairly tight structure with low air infiltration. Even at 81%,your heating system should be performing reasonably well.
What are your options?

You could spend thousands and get maybe 5 to 10% better efficiency from a new boiler.

Or you could keep your present boiler and spend a few hundred on ancillary boiler controls and increase the efficiency of the SYSTEM a few percentage points.

You can incorporate products like outdoor reset controls by TACO and TEKMAR or a Becket Heat Manager.

Do a search for these items and see what others have to say about their results.

I'd opt for the less expensive alternative first as the payback period is way less than a new boiler.

Robert O'Brien

\"a bit costly isn't it.\"

At $5/gallon it costs more not to have it! BTW Heating oil futures are up 12 cents today.

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Mitch_6

Heat loss

Just a rule of thumb 40 btu per sq foot you are at 54,000 and given that not all zones fire at once I would try down firing to the minimum allowed by the mfg. Worst thing go back up.

Mitch S.

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Toddid Goldsmith's

Only 81%

John do you have the print out from the efficiency test? What is the CO.2%? Do you know what size nozzle? What is the oil pump pressure? Stack temp. 550, that sounds high.

Leo_10

My experience

I do oil work for an oil company so we inherit everyone's equipment. That model tends to run with high stack temps by it's design. Now it was probably installed by a bid that the contractor used. So, you bought the house you own it. Your choices, buy a new boiler, whine that the contractor screwed you or spend a few bucks on controls as others have suggested. The controls are cheaper and could be used in the future on another boiler. If the house is new and was built well ie tight it may not use a lot. My parents have a small modular ranch built for electric heat in the 80's. It uses 800 gallons a year, has a tankless coil and a plane jane boiler. My mother keeps it warm.

Good Luck in your search for options,

Leo

Steamhead (in transit)

Right, Robert

and here are the specifics:

Standard firing rate is 1.00 gallons per hour (probably a 0.85 at 140 PSI if it has a Beckett burner), net output rating 102,000 BTU/hour, AFUE 81%

Lowest firing rate 0.65 GPH (probably a 0.60 at 140 PSI), net rating 69,000 BTUH, AFUE 86%. If this is a Beckett burner, you'd have to have the head changed from F3 to F0 to fire this low.

John, do the heat-loss and see what you come up with. I bet you can run this thing at its lowest rate and still get plenty of heat and hot water.

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herb_4

sounds like someone got themselves a contractor that does not have a clu. there lots of reasons the stack temp is high. Did they clean out the smoke pipe at the base of the chimney properly is there blockage in the chimney itself the size nozzle plays a big part. I myself would have another service tech that knows what they are doing look at it again. like you would if you see a doctor get a SECOND OPINI!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!