Vitocell 300

S Ebels_2

A 0010 located 30' round trip from the DHW tank will provide about 30% more GPM than one doing 160' round trip. That's not even counting the head present in the DHW coil itself.

When your system calls for DHW, what temp does the VITO go to max temp or does it stay at the same temp?

bill_115

Vitocell 300

I have recently installed a Vitocell 300 storage tank fed by 2 Vitodens 200 WB 15/60 boilers. This is my first viessman installation and I am definately a novice at figuring out flow rates, and pump sizing. My problem seems to be that I run out of hot water in approximately 10 min of somewhat large capacity use. A rough calculation is somewhere between 10 gallons to 20 gallons per minute of domestic hot water use. I am using an Uponor multifunction controller which stages the boilers, does outdoor reset, controls DHW as well as many other functions. Sequence of operation is as such; DHW calls, my Taco 0010 kicks on to feed storage tank, pulling out of both boilers simutaniously out of each DHW tapping coming out of each boiler. I have installed relays to kill the Taco 0012 circs coming out each boilers heating circuit side feeding the low loss header which diverts all the energy available from the two viessman 200 wb 15/60 boilers into that 0010 and over to my storage tank. I have installed 1 1/2 in copper piping coming out of each DHW side of each boiler into my 0010 circ which needs to pump approximately 80ft to my storage tank because I had to install my tank remotely. My storage tank setting is 140 degrees, I have installed a tempering valve on my water side of my storage tank set at 130 degrees. I have a strong fealing my circulator is to small but I'm not sure at this point. Anybody with any knowledge on these Viessman systems would be greatlt appreciated! Please help!!

Marc_21

programming

Christian, lets start with the controls and programming for the boilers? Vitodens 200 series boilers are NOT compatable with aftermarket controls. Are you high firing the 15-60's? If so, there is a very slow delay for the boilers to reach high fire/167 degree temperatures.

More info is needed,

Marc

Paul Pollets

Vitodens w Vitocells

You'll have to get the DHW kit from Viessmann and install it on one of the boilers for DHW. Follow the piping and control schematics which are detailed in the installation instructions. Make sure you talk to tech services about proper integration of 'other' controls.

The storage tank should be within 15 feet of the boilers. 80 feet will be a problem.

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Derheatmeister

I Second Paul on this one,or you can do a "external demand" but the"DHW kit" will be better depending on the piping/controls and requirement/Needs...

Why two 15/60 for domestic? Very large demand?

Swimming against the stream is not recommended or tiring to reinvent the wheel is pointless,just pay the piper which is not to much compared to the time wasted!

80' is very far and shall be insulated well, the add. head may require a diff. circulator than the 0010!

Hope all works out OK.. Richard

Marc_21

If you choose to install the DHW kit, you can only use one boiler, limiting your output to 200,000/hr. With one boiler working the domestic, the other could still be heating as well. Lots of choices, the best is per Viessmann recommendations

Marc

Paul MacDougall

WHy would the distance from the boiler be a factor? If pump and pipe size are adequate, I dont see why there would be a problem. I have done two Vitocell-300-H 92 gals tanks that where over 75ft of linear pipe away from the boiler. Not critizing, just wanted more info.

heatboy_22

Where to start?

I am assuming this is a 120 gallon vertical 300? A 30° delta T across the HX around 30 GPM is about 14' of head.

30 GPM through 1.5" copper is 12' for the 160' of tube.

The Vitodens 15-60 has another 14' at 15 GPM (max flow rate).

So, with two boilers to get 30 GPM with a total head of around 40' means you would need something in the range of a Taco 1400-50 or Grundfos UP43-110.