Buffer tank question

VRM

Can get a scratch and dent Vitocell indirect at a good price. Had this idea to use it as a buffer tank and as a "preheater" for DHW. My boiler is NOT plumbed primary secondary. The Vitocell has inlets/outlets at the top and bottom of the tank in addition to the connections for the indirect coil. Would this tank as a buffer be better placed on boiler supply or return side. I've been leaning to the supply side with the boiler supply plumbed to the bottom of the Vitocell and supply to the house coming from the top of the Vitocell. I see plenty of information about 2,3, 4 pipe buffer tank piping used in conjunction with primary secondary piping but can find little about just putting a tank as a buffer inline on either the boiler supply or return.

Derheatmeister

Vitocell 100 or Vitocell 300 ?

hot_rod

The 100 is a steel tank, if it took much of a hit, the glass lining could be cracked and the tank can rust quickly.
The 300 is stainless.

VRM

Several are available, a Evia 42 300 or an Evia 53 as examples. I believe these are both SS and are not beat up much. Just light dent and scratches and already out of the box. Even if I bought new, how would I best plumb it.

Derheatmeister

hot_rod said:

The 100 is a steel tank, if it took much of a hit, the glass lining could be cracked and the tank can rust quickly.
The 300 is stainless.

What i was getting to...

Derheatmeister

Never used a Vitocell as a Buffer..However i used a Turbomax as a buffer and O2 seperation which worked out great..Good heatexchange and no problems with the Viessman WB2B

Derheatmeister

https://www.supplyhouse.com/Lochinvar-SBT030-30-Gallon-Stainless-Steel-Hydronic-Buffer-Tank?utm_source=google_ad&utm_medium=Shopping_tm&utm_campaign=Shopping_TM_New_users&gclid=CjwKCAjw586hBhBrEiwAQYEnHfQYlW2AaNJlfvW6k0xa4SneQBvJBe_K7Vo7dDTls1V1FHUpt38oeBoCAvMQAvD_BwE


Maybe this option is less $ and less brain work.

hot_rod

Derheatmeister said:

hot_rod said:

The 100 is a steel tank, if it took much of a hit, the glass lining could be cracked and the tank can rust quickly.
The 300 is stainless.

What i was getting to...

I read yo ur mind

VRM

Unfortunately its quite a bit more money for a 30 gal tank than my 42 gal scratch and dent. Also I'm not piped primary/secondary so hydraulic separation is a non issue. Thirdly no opportunity (not sure ultimate value of this) for DHW tempering thru the indirect acting as a buffer tank. If I try this right now thinking boiler outlet to the bottom of the Vito and then supply to emitters from Vito top unless I get some information to the contrary.

Derheatmeister

Are these scratch and dent of the H or V series ?

VRM

V. Evia-42 if my memory serves me.

hot_rod

This is a direct to load 2 pipe buffer piping. From boiler to indirect, large pipe at tank becomes the hydraulic separation for any system pumps and boiler pump.

Feed this tank with cold, over to the second tank, with a thermostatic mix valve on top of the second tank.