Help with moving expansion tank from supply side to the return side of circulator/boiler.

HomerJSmith

I must admit that I am somewhat confused. I don't see the take off for the monoflo space heating sys. I see on Taco zone valve and have no idea what it's controlling.
It lacks symmetry. I really don't want to be harshly critical. I'm not saying that it doesn't work.

If the sys reaches setpoint on the coldest day in winter, who am I to criticize.

If you want to change the position of the Ex tank, disconnect it from the present position at the boiler output and plug the tee. Move the tank to the tee just above the tee where indirect return flows into the pump and plug the Ex tank in that tee side port. I think that was previously suggested.

hot_rod

When in doubt, consult the installation and operation manual. Looks like you may have low water protection onboard?
Same with the piping suggestions, it shows air sep, expansion tank, fill and pump up on the supply connection.

newtonkid88

HomerJSmith said:

I must admit that I am somewhat confused. I don't see the take off for the monoflo space heating sys. I see on Taco zone valve and have no idea what it's controlling. It lacks symmetry. I really don't want to be harshly critical. I'm not saying that it doesn't work. If the sys reaches setpoint on the coldest day in winter, who am I to criticize. If you want to change the position of the Ex tank, disconnect it from the present position at the boiler output and plug the tee. Move the tank to the tee just above the tee where indirect return flows into the pump and plug the Ex tank in that tee side port. I think that was previously suggested.

The monoflo loop has been removed. I capped it off at the top of the “tree”. You can see the white teflon tape with the plug/reducer.

The single taco valve you see is for the indirect WH. 

leonz

The two hydrostat 3250 plus units I had almost blew up my boiler, the first one nearly boiled the boiler dry and the second on turned the LWCO function off.

You have a firematic valve already attached to the riello burner piping.

There is no reason you cannot have a fuel line secured to the ceiling joists.

I have Honeywell mechanical controls on my boiler and an immersed McDonnel and Miller RB-122-E low water cut off.

With that distance you should have a 2 pipe fuel system with your reillo burner so the fuel pump does not have to work as hard to pull fuel.

newtonkid88

I have decided to leave the piping as is for now. I can install tees now to make it real easy to change the expansion tank location in the future.

My reason is because the plumbing inspector told me, as a non-licensed anything, I am not allowed to touch anything before the backflow preventer. 

So I will wait until after all inspections, i get my occupancy permit. If the heating system has issues, i can easily swap the tank locations. 

Regardless, here are some more pics for the morbid curious.

hot_rod

Your call, but you don't need to touch the BFD or the fill valve. 90 down from the fill valve out port where it is, to that plugged tee that is a foot below, move the tank down there. Flip tank tank while you are at it

That puts the tank and fill at the circulator inlet and you are now pumping away. With the 3 valves you have, you would not need to even drain down the system.

If you want super simple, you could even shut off the white handle ball valve, remove the handle. Now take the ell off below the exp tank, make it a 1/2" tee, replace tank, same upside down location
Pipe from the bottom of the tee you added into the plugged tee just above the Webstone. Add a tee there also for your future return connection. Probably an hour job.

newtonkid88

hot_rod said:

Your call, but you don't need to touch the BFD or the fill valve. 90 down from the fill valve out port where it is, to that plugged tee that is a foot below, move the tank down there. Flip tank tank while you are at it That puts the tank and fill at the circulator inlet and you are now pumping away. With the 3 valves you have, you would not need to even drain down the system. If you want super simple, you could even shut off the white handle ball valve, remove the handle. Now take the ell off below the exp tank, make it a 1/2" tee, replace tank, same upside down location Pipe from the bottom of the tee you added into the plugged tee just above the Webstone. Add a tee there also for your future return connection. Probably an hour job.

I have sent you a private message

leonz

The low water cut off on the hydrostats are a dry bulb and based solely on my experience that is not something you want on a hot water boiler.