Indirect Water Heaters

Mar 1, 2012
93
Central CT
I'm in the market for an indirect water heater. The tank we have is 19 years old*
and I don't want to awaken one morning with a 1/2" of water in the basement,
since these tanks are rated for about 8 years. I know, actual results may vary.

So, I narrowed it down to four brands: Dunkirk, Heat-Flo, iBC and TriangleTube.
Their return rates are similar, all are stainless and have top tank connections,
the last being important to me since I don't want horizontal pipes that low.

Some points: our Burnham boiler has a BTU output of around 107,000 which is
under some of the products specs, so my return rates will be somewhat lower.

The surface heating area on the TriangleTube is superior since it's a tank-within-
a-tank design, but others such as the Peerless Partner have similar surface areas.

I know there are customer service and warranty issues with Bradford/White,
TriangleTube and Weil-McLain. For some reason of late Weil-McLain has
been having quality issues but nothing on the order of Burnham Boilers.

We have hard smelly water which is largely controlled and would prefer not
having an anode rod since they're not easily serviced and can actually cause
problems.

Thoughts? Thankee in advance.


*Edited from 14 to 19 years. It pays to check.
 
Last edited:

velvetfoot

Minister of Fire
Dec 5, 2005
9,976
Sand Lake, NY
Why not get an electric water heater? You're in CT, you can get a smoking rebate on a Geospring, I think.
 

Bob Rohr

Minister of Fire
Jan 9, 2008
1,265
SW Missouri
I'm in the market for an indirect water heater. The tank we have is 14 years old

and I don't want to awaken one morning with a 1/2" of water in the basement,

since these tanks are rated for about 8 years. I know, actual results may vary.



So, I narrowed it down to four brands: Dunkirk, Heat-Flo, iBC and TriangleTube.

Their return rates are similar, all are stainless and have top tank connections,

the last being important to me since I don't want horizontal pipes that low.



Some points: our Burnham boiler has a BTU output of around 107,000 which is

under some of the products specs, so my return rates will be somewhat lower.



The surface heating area on the TriangleTube is superior since it's a tank-within-

a-tank design, but others such as the Peerless Partner has similar surface areas.



I know there are customer service and warranty issues with Bradford/White,

TriangleTube and Weil-McLain. For some reason of late Weil-McLain has

been having quality issues but nothing on the order of Burnham Boilers.



We have hard smelly water which is largely controlled and would prefer not

having an anode rod since they're not easily serviced and can actually cause

problems



Thoughts? Thankee in advance.

Tank leaks usually start as a pin hole, not a major leak. You can buy moisture sensors to alarm you if you don't check the basement regularly.

I think HeatFlo builds the IBC tanks. I do like the smooth, large diameter stainless coils they use. HeatFlo is a small company and they have great quality control and are easy to reach.

TT use to build the Weil Tanks, maybe still do. I've heard some issues of late with leakers. The leaks are in the steel outer tank portion.

Crown and Burnham were the same tank once upon a time, both from Belgium as I recall.

Of that group, I would go with HeatFlo.

HTP has some nice tanks, built here, but they have a finned cupornickel coil, not my favorite coil design, especially with hard water. I think they had a smooth coil version at the AHR show. An import maybe?

It odd, but in some areas SS outlast glass lined, in other area the opposite. If you have a glass lined now, and it has lasted 14 years, you might stick with that.
There are anode rod choices if you have water that reacts.

Bock still builds a nice, heavy gauge, thick glass lined tank. It has a large diameter smooth coil for great HX and low pressure drop. Also dual anode rods.

There are segmented anode rods available if you need to replace one. Or electronic anode rods.
 
Mar 1, 2012
93
Central CT
Thanks for all the responses.

Velvet and Maple: Thanks, I didn't know that. ( cue Johnny Carson )
Two Reasons I can reject upon:

1) CL+P ( bastids just upped the rate ); and
2) I don't need a 50G capacity tank.

Thanks, tho.


Bob: Thanks for that great overview. I was disappointed in TT after reading
a few things here'n'there, thanks for the verification. Too bad; great design.

Fins: Yup, as I thought. Not good for pipe cloggers as our water.
So it's down to the Heat-Flo then, I'll pick the contractor based on that.
BTW, like Peerless too, but it has fins and side connections.

The others are well rated too.

Thank You VERY MUCH all, this board is all kinds of awesome.
 

maple1

Minister of Fire
Sep 15, 2011
10,025
Nova Scotia
How much oil do you burn during non-heating months to heat your dhw?

Our plain 80 gallon electric tank costs about $30/mo at 0.18/kWh, family of 5. Doing it with oil for the 17 years before that was about 3/4 gallon oil/day. Big savings with electric. I would consider the need to replace an oil based component as opportunity to move to something much more efficient.
 
There are only three to consider today.

NTI Trin and Stor, Crown's MegaStor and the Viessamann's VietoCell Ti Stainless tank. All stainless, all smooth tubed HX, all super-insulated with service ports.

The average glass-lined tank has a 10 year life, the average SS indirect well over 20!

The heat capacity of the tank usually has little to do with your DHW load. If the tank can absorb the full output of the boiler you have, you are good to go.
 

BoilerMan

Minister of Fire
Apr 16, 2012
1,717
Northern Maine
I have a Heat-flo and am very satisfied with it. Stay away from anything with finned copper for the HX as it will scale and not work well in just a few years.

Heat-flo also has indirects with an electric element, best of both worlds if you ask me. Indirect for the heating season and electric for the summer, all in one!

That said I use a heat-pump water heater in conjunction with my indirect. Don't get any smaller than an 80gal if planning on any type of heat pump, slow recovery but cheap to run.

Bottom of anyone's list is Vaughn, Amtrol, expensive and finned copper.

TS
 
Mar 1, 2012
93
Central CT
Velvet and Maple: Read some more including a thread started in 2012
when Velvet was in a similar boat and DANG, you guys are in the ballpark.
I looked at my rough numbers and shore 'nuff, 150g in our lil' Bo Peep
cape is what we consume. Again, numbers are REAL rough.

D'oh! can't believe the time burned reading all this and now I have to
consider everything. Good thing I don't run on oil. CT Light and Power
is currently charging 13¢ kwh direct. I'd prefer to get indirect electric,
which means my neighbor pays the bill.

BoilerMan: GREAT compromise there. Have you crunched the winter
numbers? Oil ain't gonna remain cheap. Tell you this, no way we're
going to gas or tankless. Simple is best. Not even digital. I lost more
fingers ... never mind, bad joke.
 

Seasoned Oak

Minister of Fire
Oct 17, 2008
6,485
Eastern Central PA
I cant even see the difference in my bill when i switch to electric hot water in the summer, the 30 Gal electric water heater must only use as much electricity as the fan and feed motor on ,my solid fuel boiler. And the 30 gal provides plenty of hot water for 6 people. My rates are about 10 c a KWH.
 

maple1

Minister of Fire
Sep 15, 2011
10,025
Nova Scotia
Velvet and Maple: Read some more including a thread started in 2012
when Velvet was in a similar boat and DANG, you guys are in the ballpark.
I looked at my rough numbers and shore 'nuff, 150g in our lil' Bo Peep
cape is what we consume. Again, numbers are REAL rough.

D'oh! can't believe the time burned reading all this and now I have to
consider everything. Good thing I don't run on oil. CT Light and Power
is currently charging 13¢ kwh direct. I'd prefer to get indirect electric,
which means my neighbor pays the bill.

BoilerMan: GREAT compromise there. Have you crunched the winter
numbers? Oil ain't gonna remain cheap. Tell you this, no way we're
going to gas or tankless. Simple is best. Not even digital. I lost more
fingers ... never mind, bad joke.
I wasn't necessarily saying you NEED to go electric - the main thing is now you've more fully assessed your situation and are considering it. I always had this 'phobia' of 'expensive electric hot water' the whole 17 years I had my oil unit, and ignorantly kept the oil guy coming all those years. Just didn't think about it much. But after having sent the oil man packing & getting rid of all our oil stuff 3 years ago - should have done it long ago, at least on the DHW side. I had a tankless coil, which is worse than an indirect, but if your oil boiler isn't cold start it might be almost as bad. We were looking at an oil tank replacement in our very near future - that was the real tipping point for us in yanking the oil out all together when I had to pick a backup heat source.
 

Bob Rohr

Minister of Fire
Jan 9, 2008
1,265
SW Missouri
And of course a dual coil with electric element would allow multiple inputs solar, wood fired, or electric. Caleffi and others sell this type of tank for triple purpose.

I believe HeatFlo does also. HeatFlo sells that tank under a bunch of names, once you recognize the "look" you will know the manufacturer.
 
Mar 1, 2012
93
Central CT
I always had this 'phobia' of 'expensive electric hot water' the whole 17 years I had my oil unit, and ignorantly kept the oil guy coming all those years.
This. The cost of apathy. Guilty as charged.
 
Mar 1, 2012
93
Central CT
Boiler Man has it. The Heat-Flo looks good, but one of the few that we can't get here. Of course we just accepted the UPC and will, for the first time, allow single-wall indirects "officially" here in MN; whenever the Governor signs...
Single-wall or all indirects? That's odd. Could be an interesting history there.
Someone will write a book. Not me. That finger joke again.
 
Mar 1, 2012
93
Central CT
And of course a dual coil with electric element would allow multiple inputs solar, wood fired, or electric. Caleffi and others sell this type of tank for triple purpose.

I believe HeatFlo does also. HeatFlo sells that tank under a bunch of names, once you recognize the "look" you will know the manufacturer.
Yep, iBC doesn't bother to disguise theirs much. Slap on an iBC sticker
and throw it on the truck.

BUT ... anudder problem. I can't seem to find a manufacturer of these
UNDER 60g ... what the heck? I need no more than a 40g tank! We
have an Aero CF32T and has served us well.

Lastly, our boiler is a small Burnham PV83WC, yes, the "Notorious
Leaker". No leaks, knock on wood. The Carlin oil burner is set to .75
and is well under 100k BTUs. No idea if there's a Low Limit on it. The
Honeywell aquastat on the Aero used to be set at 140°F, but the new
oil guy dialed it down to 120°F, or so he said. Legionairres?
 
Hi Hot Rod,

I have a Rheem with single element and two 1 1/4" side taps at the bottom.

The possibilities are endless...

120°F is the new ridiculous standard. 120 at the water heater, body temperature at the tap; at least until the mixing valve gets tired and the thing gets colder still.

Legionella? It will kill you, for sure. Guess you have to pick one.

Single wall of any kind not allowed. I might right the book but it will be short one. I can say that few showed up at the meeting and I was nearly alone presenting the case for the majority of indirects, plate HX and nearly all of the combi boiler water heater appliances taken for granted nearly everywhere in the world.
 

BoilerMan

Minister of Fire
Apr 16, 2012
1,717
Northern Maine
I cant even see the difference in my bill when i switch to electric hot water in the summer, the 30 Gal electric water heater must only use as much electricity as the fan and feed motor on .
I don't know about this statement..........As a previous owner/operator of an electric water heater (30gal) I can say it cost $30-40 a month to operate for my wife an I. Our rate is .17/kWh. Or between 176 and 235 kWh. Or roughly 600,500 - 800,800btu for a 100% total efficiency. Figure 85% of those numbers for standby loss (older heater). This is my personal experience YMMV. But certainly more than a fan............

And of course a dual coil with electric element would allow multiple inputs solar, wood fired, or electric. Caleffi and others sell this type of tank for triple purpose.

I believe HeatFlo does also. HeatFlo sells that tank under a bunch of names, once you recognize the "look" you will know the manufacturer.
My HeatFlo was marketed as an Oventrop solar tank. Just the sticker, still the HeatFlo numbers and name.

TS
 
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Bob Rohr

Minister of Fire
Jan 9, 2008
1,265
SW Missouri
Hi Hot Rod,

I have a Rheem with single element and two 1 1/4" side taps at the bottom.

The possibilities are endless...

120°F is the new ridiculous standard. 120 at the water heater, body temperature at the tap; at least until the mixing valve gets tired and the thing gets colder still.

Legionella? It will kill you, for sure. Guess you have to pick one.

Single wall of any kind not allowed. I might right the book but it will be short one. I can say that few showed up at the meeting and I was nearly alone presenting the case for the majority of indirects, plate HX and nearly all of the combi boiler water heater appliances taken for granted nearly everywhere in the world.

I think the State of Montana recently dropped the double wall HX requirement, maybe others States will follow. Thanks for carrying the torch :)

Manufacturers hate building double walled HXers. Performance, corrosion, cost, leak path, all sorts of challenges.
 
Mar 1, 2012
93
Central CT
As I understand it, the solars are basically indirect / electric bkups
with expanded port options. My main thing here is waste during the
summer months. I'm guessing we could've gotten away with turning
off the boiler during the summer but it wouldn't have gotten the call
for heat anyway, which is the beauty of an oil- or electric-fired WH.
We never did that. Then again, I don't think it's good for having the
oil settle too much. Over-worried?

The other prob we have going to an indirect / electric bkup is tank
size. We don't need anything larger than 40g, but all these units
start at 60g. As stated above, our 32g oil-fired Aero served us well.
Would getting a 60g be stupid just to get bkup? Now, Oventrop is
just upstairs from where I sit, so parts and service won't be an
issue. Also noted they're Heat-Flos too. They're everywhere!

Correction: The Aero was put into service in '96, so it's actually
nearly 20 years old, forgot to mention that. I personally think that
all that hard water has actually kept it in service by plugging it up!
 

Seasoned Oak

Minister of Fire
Oct 17, 2008
6,485
Eastern Central PA
I don't know about this statement..........As a previous owner/operator of an electric water heater (30gal) I can say it cost $30-40 a month to operate for my wife an I. Our rate is .17/kWh. Or between 176 and 235 kWh. Or roughly 600,500 - 800,800btu for a 100% total efficiency. Figure 85% of those numbers for standby loss (older heater). This is my personal experience YMMV. But certainly more than a fan............
My electric bill is pretty much the same all year ,when the stoker is off the electric water heater is on ,save for a bump for late summer AC . My only explanation is the water heater does not use much more electricity than my boilers fan and pusher motor which does run 24/7 during the heating season.
Im certain the Electric Water heater cost less to run than any oil fired appliance. My rate is .10 so that helps
 

Bob Rohr

Minister of Fire
Jan 9, 2008
1,265
SW Missouri
As I understand it, the solars are basically indirect / electric bkups
with expanded port options. My main thing here is waste during the
summer months. I'm guessing we could've gotten away with turning
off the boiler during the summer but it wouldn't have gotten the call
for heat anyway, which is the beauty of an oil- or electric-fired WH.
We never did that. Then again, I don't think it's good for having the
oil settle too much. Over-worried?

The other prob we have going to an indirect / electric bkup is tank
size. We don't need anything larger than 40g, but all these units
start at 60g. As stated above, our 32g oil-fired Aero served us well.
Would getting a 60g be stupid just to get bkup? Now, Oventrop is
just upstairs from where I sit, so parts and service won't be an
issue. Also noted they're Heat-Flos too. They're everywhere!

Correction: The Aero was put into service in '96, so it's actually
nearly 20 years old, forgot to mention that. I personally think that
all that hard water has actually kept it in service by plugging it up!
With a solar tank, the electric element is about 1/2 way up the tank, so it only heats the upper portion, leaving the bottom cold for best solar input.

So a 60 gallon solar tank, when run on the electric element only give you about 30- 35 gallons. If you are use to 40 gallons of DHW, you might consider an 80 gallon solar tank.
 
Mar 1, 2012
93
Central CT
Thanks Bob. Still dunno if having a 60g indirect / electric bkup
is the right choice since the most we have now is 32g. Unwise?

Your point in the 2nd post is valid: if the Aero ( Bradford White )
glass-lined worked well, stick with that.

So perhaps I've finally narrowed it down to Bradford, if they come
with an electric backup, or Heat-Flo. But would a 60g tank, which
is the smallest these seem to come in, be inefficient with the boiler
I have? Just as BoilerMan, I want the best of all worlds.
 

Bob Rohr

Minister of Fire
Jan 9, 2008
1,265
SW Missouri
Thanks Bob. Still dunno if having a 60g indirect / electric bkup
is the right choice since the most we have now is 32g. Unwise?

Your point in the 2nd post is valid: if the Aero ( Bradford White )
glass-lined worked well, stick with that.

So perhaps I've finally narrowed it down to Bradford, if they come
with an electric backup, or Heat-Flo. But would a 60g tank, which
is the smallest these seem to come in, be inefficient with the boiler
I have? Just as BoilerMan, I want the best of all worlds.

There are some 50 gallon solar tanks out there. Keep in mind the electric element, being in the middle will only heat the upper 1/2 of the tank. So with a 50 gallon solar tank, expect 25- 30 gallon of HW.

The 60 gallon buys you some wiggle room, nobody wants to run short of DHW.

The HeatFlo 60 with element would be my suggestion. Look for it as an Oventrop, or HBC and shop price.

Here is a peek inside a dual coil version. Nice thick insulation. I like the large diameter SS coils, well spaced so they don't lime up. The top connections are handy also.
 

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Seasoned Oak

Minister of Fire
Oct 17, 2008
6,485
Eastern Central PA
The 60 gallon buys you some wiggle room, nobody wants to run short of DHW.

.
There is one exception ,teenagers. When you have teenagers who want to spend an hour in the shower running out of hot water is a great way to cut it short. I have a 30 Gal electric and I never run out during a shower,cant say the same for the teenagers.