cost of hot water from boiler?

Rick_41

Any "estimate" of how much it

adds to an oil bill to have the boiler to provide hot water? Other than

the advantage of being able to shut down the boiler in the non heating

season, I'm wondering if its wise to separate the hot water, to even an

electric one, (during move outs) because it seems that tenants

understand the electric bill is what it is and can't understand high

oil bills that hit them all at once. Ie: a tenant is complaining about

how she has spent over $900 this year for a pretty good sized 3 bedroom

in upper NYS.

She has two boys and cloths and dish washer. I'm wondering what your guess is on the % of her oil bill is for hot water.I KNOW there are a lot of varibles,..I'm looking for just a thoughtful guess.

EricAune

Domestic utility

I use a benchmark of 18% based on estimated national average.  This is not specific to oil/gas/electric but rather what the typical household spends monthly for domestic water heating. 



Also note this is mostly based on the fact that "most" homes have a separate water heater.  Not the use of a boiler/indirect combination or a tankless coil.

Jean-David Beyer

cost of hot water from boiler?

I happen to have figures for my W-M Ultra 3 with an Ultra-Plus 40 indirect hot water heater on it. In May through August, there was only hot water heating in there. In September there was a trifle of heating, and it went up from there. This is from New Jersey. Here are my gas bills:



Start Date  End Date   Days Therms Gas    Delivery Gas+Delivery Customer charge Other  Total    Comment



2009-05-15 2009-05-28 13       3.15     $2.47   $1.63     $4.10             $3.30               $15.00 $22.40 Initial connection charge.

2009-05-28 2009-06-29 32       6.28     $6.91   $3.20    $10.16            $8.25                          $18.41

2009-06-29 2009-07-20 21       3.14      $3.46  $1.63     $5.09             $5.78                          $10.87

2009-07-20 2009-08-17 28       3.14      $3.45  $1.65     $5.10             $8.25                          $13.35

2009-08-17 2009-09-18 32       5.23      $5.60  $2.75     $8.35             $8.25                          $16.60

2009-09-18 2009-10-21 34     21.95    $17.64 $10.95   $28.59             $8.25                          $36.84

2009-10-21 2009-11-16 26     27.09    $21.78 $13.35   $35.13             $6.60                          $41.73

2009-11-16 2009-12-16 30     60.41    $48.57 $29.78   $78.35              $8.25                         $86.60

2009-12-16 2010-01-19 33    125.72   $101.07 $61.97 $163.04             $8.25                       $171.29

2010-01-19 2010-02-19 31    111.67     $89.77 $55.04 $144.81             $8.25           -$18.39 $134.67

Brian_74

not sure how they figure it, but

according to my gas & electric company, 8% of my gas usage is for the hot water heater. The remaining 92% is for the boiler. This is for two adults, dishwasher, and clothes washer. I do have a low flow shower head.

Unknown

I thought the OP was asking,

about OIL fired units,,, not gas-fired modcons,,,, how did this thread get into that?



JD maybe?  

Jean-David Beyer

Not being a professional...

... I thought it might not make all that much difference whether the BTUs came from oil or from gas (other than the price per BTU the suppliers charge). Not being a professional, I could be wrong, of course.



Are oil burners and gas burners that different in efficiency? Or is it that the mass of water in an oil burner boiler is so different from a gas burner that cold-starting it is not practical for domestic hot water supply? I know there is less than a gallon in my gas-fired boiler, but 6 gallons in the indirect water heater jacket. So there are about eight gallons of water for my  boiler to heat up to get maximum heat transfer into the domestic water supply. And it does run cold-start.



My old oil burner was the other extreme. It had an aquastat that kept the hot water between 130F and 140F. It had a coil that could be used to make hot water, but I did not use the coil except in the wintertime to take the chill off the water going into a separate electric hot water heater. If I were not using it to heat the house, it would have been nuts, running about 2 gallons of oil per day to keep itself warm. Since I have not run my gas boiler for a full year yet, I cannot compare the cost of running it compared to the old oil one.

Rick_41

Ok

Well I'm still a bit confused to how much it costs.



So well,..what would be your best GUESS of what it costs in July  for oil costs to heat a tankless off a boiler for a family that consists of a Mother, a teenage son, and another son that comes home from school on weekends and the fact they have a clothes washer.



MY guess is about 50/month,...does that sound reasonable?