We just moved into our new 1940 era house. There is inadequate hot
water for our needs. We live in the northeast and have an oil fired
furnace with a steam heating system, radiators. The furnace is a
Peerless, circa 1977. Running through this boiler is a tankless coil
for 'instant' hot water. Everything works fine except the tankless coil
doesn't produce hot water fast enough to give a bath to my kids.
So here are my options, as I see them. . . I don't mind paying more up
front if it means fuel savings down the road.
1. Irving (my oil supplier) wants to put in a 40 gallon indirect hot
water heater that would essentially be a new zone from my furnace . .
2. My local plumber also suggested putting in an indirect heated 40
gallon hot water tank but suggested we use the existing coil running
thorough the boiler to heat the water. ... $1300 installed.
3. My friend, who is a plumber who lives in another state who I saw at
a conference this weekend suggested a sperate oil fired hot water
heater . . cost ????.
4. I was considering putting in a regular gas fired (like from home
depot) hot water heater myself. (we have a city natural gas line). And
I was also considering running the water through the coil in the boiler
to preheat it in the winter when the boiler's running anyway (not sure
if that would save money or not).
Any advice greatly appreciated. Many thanks. -Nate Greene
Climate varies greatly across the NE, with varying degree and intensity
of summer. During which you (well, at least I) would not want to be
running a steam-boiler, for a bunch of reasons. That makes the
separate water-heater preferable.
Which one, which fuel, would depend on factors invisible from here. An
oil-burner is going to cost much more than a gas-burner, and require
regular service. Your expertise with water and gas piping are a matter
for you and your building inspector, not to mention SO, and her
valuation of safety/peace-of-mind.
As an aside, it would seem that in winter, with a steam-boiler, an
"economizer" (heat-exchanger in the stack) with a loop to the hw
storage tank & a circ-pump that runs with the oil-burner, would be a
Your boiler is probably no more than 70% efficient even if it has been
maintained, the hot water loop in winter is therefore 70% and a drag on
the boiler, In summer it is less than 70% because it is a secondary heat
so maybe it is 50% efficient and heating the house a bit. When AC is on.
1300 for a new gas tank? That is high for a regular cheap water heater.
Consider 2 things, block off boiler coil and a Tankless Takagi Flash TH
-1 is the newest Takagi model out with a Ng efficiency of 92%, 95% on
propane, and will meet a 3 shower house needs. You will save on standby
loss 10-20% , and never run out of hot water. I have a Bosch-Takagi
Tankless and wont go back to tank. My summer gas bill is 6-8$ , I took
out an electric tank and electric went down 25-30$. And my unit is only
82% efficient. There are a few gas tankless units out from 82-87%
Rinnai is good also, but 92-95% is the new Takagi TH-1 www.Takagi.com
Takagi makes Bosches large units of 83% efficiency and are sold at HD
and Menards, tankless will save you the most money in utilities.
I lived in an 1850s house with an oil fired steam heating system
and a water heating coil in the boiler for seventeen years.
During the heating season the domestic hot water got TOO hot
because it was inside boiling water. During the rest of the year
the aquastat which heated the boiler feed water to heat the
domestic water maintained a sensible temperature.
Questions: Is the coil clogged? Is there some crud inside the
coil which is reducing the rate of heat transfer so it does not
heat water fast enough? Is the aquastat [which controls the
boiler feed water temperature when the thermostat is not telling
the oil burner to make steam to heat the house] set at the proper
Thank you everyone so much for the information. Sounds like a seperate
gas heater is the way to go. I'll have a pro do the gas line.
Bob- If I do a preheat through my boiler. would I remove the mixing
valve from the current tankless coil and just do a straight shot
through the tankless coil then into my new hot water heater, or would I
leave the mixing valve for safety.
Also anyone know the pros and cons of tankless versus tank gas hot
Thanks again. I am really grateful for the response. -Nate Greene
Marilyn & Bob wrote:
I just called my gas company. Although I have a gas line into my house,
it has been 'retired'. I was assuming it just needed to be turned on,
but I was wrong. They want about $2000 to run a new line into the
house. But if I convert my furnace to natural gas, they'll do it for
free. Any opinions?
You could get a new 83% gas boiler and save over your old unit,and have
cheaper gas to use for cooking and the dryer. Run your numbers before
you say no, I pay apx 1$ a therm Ng and 0.12kwh. electric for me is
several times more than gas or aps 3$ a therm, compared to Ng 1$ a
therm. Is you go all electric for cooking and your dryer and HW, you
will be paying many times more then if you convert. A new gas boiler may
save you 10-20% and yours is not new at all . I would go new boiler,
and tankless Takagi and a free gas line. The Takagi drawback is 2- 3
reduced flow showers at one time I dont find a drawback I like the
savings on my bill.
Strongly recommend the gas water heater supplied by the tankless coil. If
you (or the local codes) decide not to install it yourself, you'll still do
better with a professional install of a gas heater than the other two
solutions. And you save lots but not having to fire up your boiler in the
non-heating season. If you feed the heater from the tankless coil you will
save a lot of gas. Our gas bill tripled during the summer when the boiler
(hot water, not steam) was not running. Also since your boiler is almost 30
years old, you might need/want to replace it in the next decade. When you
do, you could save a lot by getting a new boiler without a tankless coil
(especially if you choose gas heat) and the gas hot water heater would fit
right into that setup.
<scott firstname.lastname@example.org> wrote in message
Furnace conversion sounds cheaper than a new gas line...
Doug Miller (alphageek at milmac dot com)
Nobody ever left footprints in the sands of time by sitting on his butt.
And who wants to leave buttprints in the sands of time?
I think you answered your own question. Do #4. You can buy a gas
heater for $150 to $200 (or more). If you do the work yourself, the
whole job should cost you $500 tops, and probably less, unless you
need lots of pipe or something. Go ahead and use the coil to
pre-heat. I did the same thing with a solar pre-heater, and in the
hottest part of the summer, the water heater rarely or never ran. It
only makes sense, the hotter the water when it goes into the heater,
the less the heater works, thus the less fuel you need.
It sounds like your "Irving" is trying to find a sucker to boost their
If you do install a gas tank, I'd use a few valves and some pipe and
design a direct cold water inlet. In other words, you can turn a few
valves and get cold water direct to the tank, *OR* reverse the valves
and use the preheater. That way, if you dont want to use the
preheater for some reason, you can turn it off.
It looks like this question may no longer be relevant if you decide to get a
new gas boiler without a tankless coil. But if you still need an answer,
I'm sure someone else here could supply it. Ours was an oil fired boiler
for a hot water (not steam) heating system, so no mixing valve was necessary
as the water was at an appropriate faucet temperature when it left the coil.
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