Best Place for Circulator and Expansion tank

Mail4tommo

Where would the best location be for the circulator and expansion tank in this primary secondary set up? A or B for the circ? and the circ after the expansion tank I know that . Im just confused

PriSec.png

Thank you

Jamie Hall

Unless the boiler has one inside, you need pumps at both locations. And in that case, probably the better location for the tank would be on the inlet side of the pump at B. That would also be your pressure reducing valve location.

Mail4tommo

@Jamie Hall so three pumps?

Mail4tommo

So the inlet side of b because the one on the zone circuits using (zone valves) and before B both would be technically pumping away from the tank correct?

Jamie Hall

I misread your drawing. My error, and I apologise. I see now that there is a pump shown on the zone manifold. You need one other pump, and it could be at either A or B — doesn't matter unless the boiler has a high head loss, in which case B would be the preferred location, pumping away from both the boiler and the expansion tank.

hot_rod

there are a number of ways to pipe a PS system

This shows the distribution loop as the primary, as it has the expansion tank connection.

The large pipe size, pink line, becomes the reference for the boilers circulator to the expansion tank.
It could be a single zone, multiple circs or one circ and zone valves on the distribution

This is a 6 zone with circulators example.

Mail4tommo

Ok, just wanted to confirm how I planned it. Makes sense at B if high head loss. Appreciate it. Thanks @Jamie Hall

HomerJSmith

I don't think your drawing is correct. The side ports on your tees should be on the boiler side not the distribution side. You need a pump on the boiler circuit and a pump on the distribution side if zoning with zone valves. @hot_rod diagram.

To your Ex tank question, It really doesn't matter. If it is on the distribution side, just make sure that the pump is pulling from the Ex tank. Same if the tank is on the boiler side

The air eliminator should be on the boiler side on hot water from the boiler to the distribution side and the boiler pump should be pumping into the boiler intake.

I'm assuming it's a Mod/Con.

EdTheHeaterMan

I would make the system loop the primary loop by placing the expansion tank on the section of the system loop down stream of the closely spaced tees. As shown here:

The loop with the expansion tank is the primary loop. I would also place a air seperator on that pipe where the expansion tank is located and also place the water feed connection at the expansion tank location. Ask me why if you need to know.

hot_rod

yet another option, you want the air purger close to the hottest temperature

The first option a few posts up makes for a nice clean piping arrangement, boiler “injects” heat into the primary loop

Mail4tommo

@HomerJSmiththanks homer for taking your time

@EdTheHeaterMan Thank you for taking the time to recreate my drawing . And yeah the separator is at the hottest point and (if possible @ the highest) because the higher the temp the more oxygen you get out of solution.

@hot_rod Thank you as well, Appreciate it love the napkin drawing. Know my only question is to as why the circ is on the return in @EdTheHeaterMan drawing ? (maybe going off the assumption this is a high head boiler[Mod con]?? which it is a cast iron.

and why @hot_rod your circ is on the boiler loop? Just some clarification here. I know they will both work but whats the reasoning?

My plan is going with the paper drawing, even though it would be a cleaner look with @EdTheHeaterMan drawing

Mail4tommo

@hot_rod Just noticed it wasn't a napkin, my eyes are getting tired Apologies.

EdTheHeaterMan

@Mail4tommo the boiler is the primary loop in the napkin drawing since the expansion tank is on the boiler loop. That is a perfectly good way to do the job with a cast iron boiler.

Would you like me to draw it for you? give me the brand and model of the boiler and I will even match the colors. Taco Pump will be green, B&G pumps will be red and Grundfos pumps will be burgundy … generic pumps are blue!

Mail4tommo

@EdTheHeaterMan I appreciate it Ed , I'll make it on this one. You guys are the best truly!