New to the trade

Probie

Hi I'm currently new to the HVACR trade. I have been an apprentice for about 2 months now and i was doing a routine on two oil burners today and noticed they both had 2 expansion tanks and was wondering why a system would have 2 expansion tanks instead of one?

SWEI

Was there a tankless coil or an indirect water heater?

That would (in many cases, and certain jurisdictions regardless) explain the second expansion tank.

Weezbo

this is interesting ...

do you recall how these tanks were arranged and piped ?

i can see some probability in Swei's reply yet i also am interested in what you encountered ....what were the boilers pressure readings ?

were the tanks different colours one white on grey for an example?



or were they on a common headder ?



if they were on a common headder were they side by side as it were in like Twined?

twined tanks though fairly uncommon has some redundancy type factor ...



a few well, almost a decade back i recall some really large tanks that were twin tanks that were used in a process of drawing larger quantities of different temp water from different levels of a lake all lashed up to like a university town ,

and in the past i have seen this done although in the last 20 years or so not so much..









.....

Probie

The Expansion tanks

all 4 of the expansion tanks ( 2 piped into each boiler set up) were the same colors (grey). one of the boilers hot water coils (there was two hot water coils for this boiler) was on the 3rd floor of the house the tridicator read 20 psi and both expansion tanks had 20 psi in them. The second boiler was used for the 1st floor hot water coils (Two) and the hot water tank which was next to this boiler the hot water coils were also in the basement with the boilers. This boiler read 12 psi on the tridicator and both expansion tanks had 12 psi in them.



As for the exact set up i know on the boiler for the 3rd floor the expansion tanks were across from each other but i don't remember at this moment the EXACT placement of the expansion tanks.



Hope this helps. Any information helps thanks,

Probie

Bob Gagnon plumbing and heating

Were They

Large systems? They may have used two of the more common smaller expansion tank, instead of getting one bigger tank, or maybe they didn't have room for the longer tanks? Welcome to the trade Probie, hang around here and you will learn A LOT.



Thanks, Bob Gagnon