Two Vitodens Questions

Mike T., Swampeast MO

1) Any idea why the recommended piping diagrams always show pumping towards the point of no pressure change? Couldn't have been easier where I just installed, but it just seems a bit strange. Perhaps because when installed to spec. it's impossible to lower the return pressure to problem levels?

2) When NOT using for DHW and a heating season about of about 5 months, what setting for the off time (around 7 months)?

A: If left "on" it won't fire unless heat is needed.

B: If left in "standby" mode the circulator will "run for a short time every 24 hours to prevent circulator sieze". Will also go into "no system freeze" mode if temp should happen to drop suddenly or unexpectedly.

C: If turned "off" nothing happens.

Choice "B" with the circulator exercise mode is my gut reaction. Suggestions? Comments?

S Ebels

Answers

Question 1. Internal pressure switch on the Vito. They want to be sure to maintain a minimum of 10#'s if I recall correctly. I still pump away but use a higher static to ensure no PS problems.

Question 2. No indirect? If so the pump will be running daily anyhow. If you aren't making water that way then option B would be my preference.

Mike T., Swampeast MO

Thanks Steve!

Makes perfect sense with a pressure sensor on the supply side. Fully TRVd system with exceptionally low head loss and no low-loss header. With 12# static fill and only enough differential pressure to operate the TRVs, no chance of going even near sub-atmospheric without pumping away.

No indirect, so "Standby" it shall be.

mark_40

Solve All Your Problems

don't buy the hugely overpriced "orange beast" ...even Buderus is much more reasonable ... ya know, you can get the same performance with a Dunkirk Q-90 .. at like 29 % of the brand "V" price ..... viesmann would like you to belive only they can burn those BTU's in a very special way ...

marc

last time i looked

the vitodens was a very clean white.

S Ebels

Special Btu's

Learn a little more about the Vitodens. C'mon, stretch yourself a bit. There are major differences.

ALH_3

Viessmann

Everyone does it more cheaply, but no one does it better.

Check out the burner in the Vitodens. They really do burn the BTU's in a special way.

-Andrew

BTW: Viessmann boilers haven't been orange in a few years. Now they're "silver beasts"...Vitodens excluded.

Darin Cook_3

Everything else aside

the Vitodens is THE most quiet boiler. We had a customer who bought it based on that feature alone. They wanted to know if Viessman made a condensate pump, the beckett pump is too loud we have on the system.







Darin

Mike T., Swampeast MO

It HAS to be quiet because it's utterly suited to be mounted in LIVING space--IMHO it's intended for such to help keep costs down. No need for the remote control unit. Venting probably VERY short and straight up.

Were I designing a Vito system from scratch it would be in a hall right outside of bedrooms. Would build a nice cabinet around with a door-in-door front to access the programming unit. If not using frameless cabinets would simply use some knock-down connections to make the front frame removable. TRVs/FHVs of course so no other components required to "clutter things up". Only four small connections for water all heading down to the floor and a small gas line. Only one to three (in most cases) two-conductor cables and the power supply line. If there's a basement would probably put the indirect down there---otherwise put it inside the cabinet as well.

If someone does this, don't forget to use a slide coupling in the flue--otherwise you'll have a bit¢h of a service access problem. Heqq--if you have a similar application in mind, send me some WELL-DIMENSIONED (FINISH DIMENSIONS) drawings and I'll design the cabinet for you--no charge but do give me a reasonable amount of time...

Here's where I would have LOVED to put mine. Very close to scale. With forethought and creative framing a similar installation is possible even with the drawers below (not dust lined like these however).

Constantin

You're right,

The Vitodens is designed to work in living spaces - it's completely sealed combustion, zero clearance installaton for chimney and unit alike, etc.

However, it also requires very short vent stacks when used in a sealed fashion. That in turn will require some thought by architects and installers alike when the time comes to designing a building. I would prefer a roof exhaust/intake any day over the rather large (but functional!) side-vent Viessmann offers for the Vitodens.

Thus, it makes sense to mount the Vitodens in living areas. No one will notice it as long as all the other appliances (pumps, etc.) it is feeding are quiet also.

Oh, and don't forget the condensate line. The Vitodens produces a lot of water and should be fitted with a nice drain to send it into the garden or storm sewer.

Constantin

That's being a bit simplistic, no?

Granted, a Quantum Leap offers some very high AFUE numbers. Yet, I doubt it has the same thermal efficiency once you crank the return water temperatures down from 140°F, which are used by the AFUE test. In-floor or in-slab radiant systems, for example, run at much lower temperatures.

Then compare the intelligent motor logic that ramps the Vitodens up and down as modulation, wind conditions, and/or flue blockages (!!!) mandate.

Never mind the nifty plug-and-play connections, intelligent, built-in computer, outdoor reset, even a circulator pump on the smaller models. The list goes on, it is a very-well-thought-out unit.

Now, is a Viessmann unit more expensive to buy than Dunkirk? Most likely. However, how great is the difference in material cost going to affect the consumer? I doubt a complete Viessmann install is 4x more expensive as well.

In fact, with everything a Viessmann does to make your life easier, I would argue that the marginal cost to the consumer quickly comes down once you approach each supplier option as a system, rather than just the individual pieces. Ultimately, it is your role to let the consumers make a informed decision. If they want the best, why not offer it to them?

BTW, if you haven't noticed yet, I just got indoctrinated at Viessmann. The silver/orange punch was good! ;-)

Mike T., Swampeast MO

YIKES!

How could I forget the condensate?!?!

No need for other pumps if you design carefully and that built-in circulator is ULTRA quiet and so smooth that I have to use that little Grundfoss rotating magnetic field detector to ensure that it's running!

Mike T., Swampeast MO

Lots of Other Models in Europe

Ones with the compression tank built in.

Ones with a different built-in DHW production device than I see available here.

Even saw one model that I'm certain contained two circulating pumps!

Retail price in Europe is significantly lower then here even with their huge value added tax. When/if they become more common, the price is likely to drop.