Exp. tank location for Ultra

bobbyg_2

Two considerations.

1. In a primary/secondary piping the "point of no pressure change" in a secondary circuit is the closely spaced tees. The main PONPC is the air separator/expansion tank/fill valve, but in the secondary the two tees become the PONPC.....So where your secondary ciruit pumps are placed are important.

2. Air in solution (entrained in the water) will come out of solution best when water is the hottest and lowest in pressure. If not placed in hottest and lowest pressure, make provisions to collect air on all high points.

Hope this helps.

Bob Sweet

Does anyone see a problem

with installing the exp. tank/air seperator in the boiler loop rather than in the system loop?

hr

It does get a little complicated

as the Ultra, and most condensors with high pressure drop HXers, insist you pump into the boiler. So really the purger would be at the top supply connection, if the hottest point is what you are after, but the expansion tank shoud be just before the pump, which pumps into the bottom tap of the boiler.

Remember the key to condensing boiler efficiency is to bring back the water as cold as possible, so by default the purger would be at the coldest temperature if you locate it with the expansion tank at the circ location.

Primary secondary helps in the fact that the ponpc will be within that primary loop and the boiler pumps away from it. However sometimes, in the case of an Ultra connected to an indirect for just DHW, there may be no primary loop.

hot rod

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james patrick

Ultra Exp. tank

I'm going to put my Exp. tank just prior to the Taco 0011 pump to the Indirect. The DHW takes priority.

The Ultra install piping diagram shows that pump pushing the 180* water into the indirect + it will run during warmer months.

Also, my boiler primary loop only supplies a HX. That Taco 0011 pump will push the return water into the boiler.

Is this A-OK ?

BBP

bobbyg_2

I want to make sure I have this right. You only have two circulators on the system. One is used for boiler to dhw tank only, and the other is boiler to heat exchanger?

If this is the case, make sure the circulator for boiler to heat exchanger is sized right. If there are three circulators disregard previous sentence.

Will the boiler to heat exchanger set-point water temperature change, or is it a "high" temp. system as well?

james patrick

Bobs answer

I will only have the 2 Taco 0011 pumps that I described on the boiler side of the HX & IDWH. Lots of constant circulation pumps on the radiant floor side of the HX.

Plenty of head to move 11+gpm through HX & boiler HX.

Designed for 80,000btuh @ 14.6* deltaT

150* to HX, 180* to IDWH.

bobbyg_2

Sounds like you got it going on. Should work fine. I would check the pH level of the cold-water fill for the aluminum heat exchanger. (see installation manual)