Choosing an Indirect

S Davis

I like the Buderus ST series they have large clean-outs and come with a power anode monitor where the indicator light turns red if the tank looses it's anode protection, nice product




S Davis

Apex Radiant Heating

Mark Walnicki_3

Flavor of the week

Does anyone have a particular favorite choice of indirect for any particular reason? Have any of them become ones to avoid like the plague?

Over the years I've seen the indirects of Buderus, Bock, Amtrol, WM, Superstore, Phase III, etc. out there, all seemed to perform and hold up as advertised as long as they were installed correctly.

But I know some are still better than others, just been out of the loop too long, and I forget.

Thanks in advance, Mark

hr

Nice to see you back

I've had good luck with the Phase 3 or it's cousin the Weil McLain badged versions. Something about that tank in tank design that handles hard water and has a large amount of transfer surface. No fined coils to degrade, either.

If money were no object I have been inpressed with a Viesmann horizontal I recently installed. Lots of coil, nice cleanout ports, well built. But about 3 times a good indirect from other brands.

Enameled steel tanks seem to be more common. Personally I think they live as long, or longer than stainless, if maintained.

I like a tank with an inspection port, if it were my own. I doubt most homeowners would open them up however.

hot rod

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Ron Schroeder_3

preferred indirect tank

The Vitocel 300 series tanks are warranted for as long as the original residential owner owns them. They are available with an optional electronic cathodic protection should your water conditions need them. To my knowledge there is no other manufacturer's tank that either outperforms or outlasts them.

We have a twenty year old installation for DFO in Port Hardy, BC where Verticels are used as heat exchangers wherein sea water from the Pacific Ocean is warmed a few degrees to enhance the growth of Salmon fry. The installation is almost twenty years old today. There have been no failures though we did not sell this installation on the basis of the tank warranty. True story.

Mark Walnicki_3

Thanks to all!

Not exactly back, just doing some work on my brother's place. I bailed out of the industry about a year ago, went back to fixing hot tubs!

Just to make sure, the Phase III and WM the same thing? WM just threw their name on it?

Thanks again, hope all is well with you and the family.

Unknown

Mark , great to see you again

Yep , the Weil Mclain version is the Plus series , same tank as the Phase 3 , different color . I have a Plus 30 raring to go under my stairs very soon .

hr

That tank is made in Belgium

if I'm not mistaken. I don't know if Triangle Tube owns the manufacture or not?

I've seen that tank with Triangle, Weil Mclain, and Aquatherm jackets on it.

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Cosmo_3

All those tanks are great,

A few more choices are Crown Boiler Co's Megastor, HTP's Superstor, etc.

Of course if the $ are there, the Viessmann V-300 is just about without equal (get the one with the cleaning port).

I have a lot of Plus tanks ou there- I.E- Weil Mclain, Triangle Tube, Smart Tanks are a great design.

Cosmo Valavanis

Dependable P.H.C. Inc.

harvey

be carefull

The model numbers of the triangle indirect tanks do NOT correspond to the WM tanks. If you order a WM tank using Triangle numbers the tank WILL be one size smaller. I found this out the hard way To me the Triangle makes the most sense

Cosmo_3

Ha, ain't life great

I guess they think we won't figure it out ay?

Cosmo Valavanis

Dependable P.H.C. Inc.

Andrew Hagen (ALH)

Indirect Water Heaters

They are not all created equal.

Andrew Hagen (ALH)

Indirect Water Heaters

Not all are created equal.

The Superstor in the photo was removed from service because it would not perform with an 8-32 Vitodens in a retrofit. 316 stainless is hard on sawzall blades. ;-) The Superstor was replaced with a Crown Megastor. Unfortunately I have not had a chance to cut a Megastor open yet. Though we have an MS-40 that sprung a leak at the well ready to be opened up. The Viessmann vertical and horizontal tanks have impressive coils. The Crown tanks seem to be the best compromise between price and performance. Bradford White's have a very long small diameter (high head loss) coil. Amtrol's have a tightly wound coil in the bottom of the tank which is not optimal for heat transfer.

-Andrew

ScottMP

We use

Super-Stor for our standard installtion retrofit.

If we are doing a Buderus install we use Buderus tanks, they look good together

Viessmann where the customer wants the Very Best.

Andrew, you don't say why the SuperStor would work with the new Viessmann. What was the problem, beside the wrong color ??

Mark, good to see your name agian, its been a long time.

Scott

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Andrew Hagen (ALH)

Colors

It really had nothing to do with the color. I'm open to anything that's designed well.

I've watched Superstor's heat from 50 to 120 on startup, and I've watched Megastor's and Vitocell 300's do the same, as I'm sure you have also. The Superstor's take nearly twice as long to recover as the Megastor or 300 when connected to a Vitodens. The Superstor has around 1/4 the number of coils that the 300 has. That just means the boiler temp has to be run hotter to recover at the same rate. However when we're talking low mass boilers, running them up to the operating limit as fast as possible for DHW production can cause the boiler to trip safety switches.

The Superstor has quality materials and good insulation. I just wish it had a bigger coil. More than anything I wish other indirect water heater manufacturers produced a document with as much information as the Vitocell technical data manual.

-Andrew

Ron Schroeder_3

Andrew, please call me at

604-533-9445

Andrew Hagen (ALH)

Clarification

The 8-32 has some issues regarding DHW production using the internal pump. The internal pump is too small to overcome the head loss in the boiler heat exchanger and the indirect water heater coil at a sufficient flow rate to guarantee the boiler will not hit its high limit and cause a fault. Viessmann is recommending an external pump on the domestic side in order to overcome the head loss in tanks other than those Viessmann manufactures. There are also a few coding changes that will help. There is a dramatic difference in head loss.

In tanks with inadequate heat exchangers there are other problems with respect to the ability of the coil to transfer heat at an optimal rate. The reason I prefer Crown tanks to others is that there is still a relatively large heat exchanger surface area. The coil is a smaller diameter than the Viessmann coil, so the head loss is higher, but still nearly within the limits.

I'd love to spec Viessmann tanks on every job. Economics frequently dictate the use of something slightly less expensive. Many times it's already a significant price jump for the homeowner to buy the Vitodens.

-Andrew

hr

Actually, Andrew

Bradford White does have a new line of indirects. Glass lined steel tanks with very large 1-1/4" smooth coils. I prefer smooth coils to finned for the reason you showed above. I have seen that very thing hapen to all finned coils HXers, even if they are top mounted.

The problem snowballs as the repair guys keep cranking up the boiler temperature trying to get recovery back. The hotter the coil, however, the faster the minerals are attracted to them. Similar to an electric water heater element.

Of course even smooth coils will get a scale build up, but not as much as a performance hit as those finned types.

Of course none of this is the indirect tanks fault! Treat the water (soften it) if you truely want to eliminate coil (hard water) build up. None of them are designed to work with a 1?4" calcium build up!

This is another reason I like the tank in tank design, plenty of surface area. I'd put a Phase 3 up against that high dollar Viessman, performance wise, any day, all things being equal

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Andrew Hagen (ALH)

I stand corrected

Now that you mention it, I do remember seeing some advertising for Bradford White indirects with larger coils.

I find the Phase 3 interesting. The Prestige looks interesting also. I'll investigate Triangle Tube products more.

-Andrew

Kevin__Flynn

Tank-in-Tank

Hot Rod and all,

While it is certainly true that the Phase III because of the large HX surface area due to the Tank-in-Tank design, can accomodate much higher flow rates than coil type tanks.

Consider this, the hottest water (boiler water) potentially 160/180 degrees is closest to the ambient room air, increasing the stand-by loss of the boiler.

When a coil gives up its heat the only place it can go is into the water that it is heating.

Again, there is no question to the benefit of the large HX.
Just something to ponder.

Kevin Flynn

Joe Brix

other option is the reverse indirects

Like the ErgoMax, TFI Everhot, and the Thermo2000 Turbomax. Here the DHW stays in the coper coil HX surrounded by hot boiler water in a steel tank. Basically taking the tankless coil out of the boiler and putting in an insulated tank.
The indirct can double as a buffer tank for radiant systems as it holds 20+ gal of boiler water.

Constantin

well, it's one of the things...

I recall the recovery rate of the Vitocell not to be the best in class, that honor belongs to the Phase III. However, as usual, I am happy to be wrong.

But I totally agree that maximizing the HX surface inside the indirect is the only way to maximize the efficiency with which you can get the thing heated, i.e. w/o resorting to 180°F hot water. For that matter it would be nice for other indirect tank manufacturers to indicate the recovery rates at various ΔT's, not just what happens when you hit a 70°F or whatever hot tank with 180°F hot water.

hr

KF, but

at the end of the cycle isn't that outer tank closer to the 140° temperature that the inner tank is controlled to? Once the boiler cycles off, and the heat exchange has occured, the outer tank should not be at 180, at least for very long.

Insulation is a key component. I find the jacketed and injection foamed tanks have less standby loss than a cheap, thin, foil or fiberglass insulation.

This is perhaps my biggest, and only ERGOMAX complaint. A thin, poorly applied insulation. And yes, this tank is at boiler temperatures!

This is a pic of how an Ergomax arrived at my shop recently. MAYBE a 1/2" thick fiberglass, with a layer of "miricale bubble wrap" Poorly taped and applied! Hard to believe the standby loss for that tank

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Kevin__Flynn

Hot Rod

Unless I mis-understand what you mean by end of cycle, at the end of the cycle the Domestic Water will be the closest in temperature to the boiler temp, therfore the Delta T between boiler supply and return should be much closer, due to the fact that the boiler water is giving up less heat to the domestic. Unlike the begining of the cycle when the tank temp is potentially 95 degrees with 180 degree boiler supply.

Based on a pump sized for a typical 20 degree Delta T, during the begining of the cycle with 180 degree supply you should have pretty close to 160 degree return (maybe a little less depending on tank temp)with much more of the heat transfered to cooler surroundings. ie. domestic water and basement. As the domestic heats, that delta T should actually become smaller with maybe 170 degree return.

So I'm not sure where you would see that 140 degrees except maybe at the very begining of the call with a cold tank.

Forgive me if I mis-understood you.

Kevin Flynn

Ron Schroeder_3

please order

kit number 7134599 to interface the auxillary DHW pump with the Vitodens control.

Remember it is only a "jump" to the Vitocel if the customer does not yet really want the tank.

I cringe whanever I hear installers say that they push the Viessmann whenever they can. It is my understanding that these decisions need to be driven by the customers' desires. If we are pushing instead of the customer pulling then we have advanced too early to the solution.