Furd
Engineer
Okay, I lied. I use a bit over 12 therms a month for water heating. At a cost of a touch over $1.24 a therm that makes the cost of water heating for me about $15.30 a month not counting the various taxes and fees that are added.
Now if I could save 25% of the gas cost by going to a tankless heater that would translate to about $3.83 a month or just under $46. a year.
Assuming that a tank-type heater will last 10 years and a tankless will last 20 years I will save $920. in gas costs (assuming a constant price for the gas) during that 20 year span.
But let us look at a bit differently.
Say a new tank-type heater is $1,000 installed and it uses 12 therms per month at a constant cost of $1.25 per therm. In ten years it will have used 1,440 therms at a cost of $1,800.00 Add in the original cost of the installed heater and you get $2,800.00 to supply your hot water needs for ten years.
If a new tankless heater costs $3,000 to install and uses 8 therms per month (25% less than the tank-type) then over its life of 20 years it would have a total cost of $5,400.00.
Now if we break this back to a cost-per-year basis it comes out as $280.00 per year for the tank-type and $270.00 for the tankless.
None of this takes into account that a tankless heater is more likely to have some kind of failure or will likely need a bit more maintenance than a tank-type. Also, the 20-year lifespan I used for the tankless may be a bit optimistic.
I really wish that the manufacturers would improve the total efficiency of the tank-type heaters but even as things stand today I won't be going tankless just to save a measly ten bucks a year.
Now if I could save 25% of the gas cost by going to a tankless heater that would translate to about $3.83 a month or just under $46. a year.
Assuming that a tank-type heater will last 10 years and a tankless will last 20 years I will save $920. in gas costs (assuming a constant price for the gas) during that 20 year span.
But let us look at a bit differently.
Say a new tank-type heater is $1,000 installed and it uses 12 therms per month at a constant cost of $1.25 per therm. In ten years it will have used 1,440 therms at a cost of $1,800.00 Add in the original cost of the installed heater and you get $2,800.00 to supply your hot water needs for ten years.
If a new tankless heater costs $3,000 to install and uses 8 therms per month (25% less than the tank-type) then over its life of 20 years it would have a total cost of $5,400.00.
Now if we break this back to a cost-per-year basis it comes out as $280.00 per year for the tank-type and $270.00 for the tankless.
None of this takes into account that a tankless heater is more likely to have some kind of failure or will likely need a bit more maintenance than a tank-type. Also, the 20-year lifespan I used for the tankless may be a bit optimistic.
I really wish that the manufacturers would improve the total efficiency of the tank-type heaters but even as things stand today I won't be going tankless just to save a measly ten bucks a year.