Biting the bullet to repipe this boiler to pump away

sixplex

Hey guys, so the village idiot has decided to bite the bullet and repipe to pump away, and add a micro bubble eliminator and magnetic dirt eliminator.

Is this the correct way to do it?

Do I need to change or add anything to the way expansion tank and relief valve are piped?

Slant Fin manual has separate pipes from the boiler for the expansion tank and relief valve, my boiler does, not sure what to make of it


NOW




WAY TO GO?


SLANT FIN MANUAL

hot_rod

adding the air sep and circ in the pipe where the insulation is removed?

while not pretty the exp tank and relief could stay as is and you will be pumping away

How much piping do you want to redo?

mattmia2

You probably want to look at this in how do you get enough flow in your monoflow loops besides pumping away. i thought the piping did something different at that radiator that didn't heat, i don't think the problem there is air. I think either you don't have enough velocity in the main or the monoflow tee is damaged or clogged.

Others know about sizing circulators and piping better than i do but the fact that it reduces at the boiler makes me think someone didn't understand what flow the monoflow system needed.

oh, and hot water piping is a lot more forgiving than stream piping, there are a lot of ways you can set up the near boiler piping and still have it be correct, especially with a cast iron boiler.

sixplex

hot_rod said:

adding the air sep and circ in the pipe where the insulation is removed?

while not pretty the exp tank and relief could stay as is and you will be pumping away

How much piping do you want to redo?

Correct. Where insulation is removed.

How much piping? As much as needed i guess without chasing marginal improvements.

sixplex

mattmia2 said:

You probably want to look at this in how do you get enough flow in your monoflow loops besides pumping away. i thought the piping did something different at that radiator that didn't heat, i don't think the problem there is air. I think either you don't have enough velocity in the main or the monoflow tee is damaged or clogged.

Others know about sizing circulators and piping better than i do but the fact that it reduces at the boiler makes me think someone didn't understand what flow the monoflow system needed.

oh, and hot water piping is a lot more forgiving than stream piping, there are a lot of ways you can set up the near boiler piping and still have it be correct, especially with a cast iron boiler.

Agreed about the bad rad. There could be a blockage in a specific spot due to a long term air pocket that corroded the pipe.

I still need air removal at the boiler.
My basement rads (below main) are full of magnetite, flushing the system doesn't remove it.
Also when both my pumps are pumping on the return (taco 007 equivalents at medium), that may cause issues from what i understand.

MikeL_2

  The sub zone return piping shown is less than ideal & can be improved. Bullhead tees create turbulence & flow restriction as the water from multiple zones enters the bottom of the tee.

clammy

If you have 1 zone mono flow and one baseboard it s better to use a separate pump for the mono flow and one for the baseboard other wise you will need to install a circuit setter in each zone to balance the flow when both zone are calling . Usually what happens is the mono flow suffers until the baseboard zone is satisfied due to less restriction in baseboard zone . I ve found it far easier to install a separate pump due to the pressure drop through the mono flow system in some system it’s not noticeable but in larger mono flows w micro zoned baseboard zones it’s usually hard to get flow everywhere all at one time and as zones shut off flow increases in other again either seperate pu p or zone valves w flow setters w gum meters built in callifee comes to mind and multi zones don’t forget check valves . As time advances and the price of taco valves ( china resido Honeywell are garbage ) it may be much cheaper to just use a small ecm circulator .
Peace and good luck clammy
If using any ecm pump please install a magnetic separator Adey comes to mind it will save your pump due to maganite in most steel piped system and is cheaper than a mid priced ecm circulator .

sixplex

clammy, not sure what you mean by 1 zone monoflow and 1 zone baseboard.
my entire system is monoflo.

single supply, 2 returns (each return has 2 sub returns)
-1 reponsible for 16 cast iron baseboard rads and 2 free standing rads ABOVE the "main" (2 floors)
-1 responsible for 10 cast iron baseboard rads and 1 free standing rad BELOW the "main" (basement)

I always wondered what happens when circs on both zones are both running

mattmia2

I'm looking more closely at the piping. Does the supply go to a tee at the center of the system and both zones branch off from essentially the center of the loop?

Does that tee in the return at the back left near the ceiling that connects go a smaller pipe with a valve go to a compression tank in the ceiling or where a compression tank used to be?

mattmia2

MikeL_2 said:

  The sub zone return piping shown is less than ideal & can be improved. Bullhead tees create turbulence & flow restriction as the water from multiple zones enters the bottom of the tee.

The only tees I see are the monoflow tees that feed some emitters close to the boiler.

MikeL_2

mattmia2 said:

  The sub zone return piping shown is less than ideal & can be improved. Bullhead tees create turbulence & flow restriction as the water from multiple zones enters the bottom of the tee.

The only tees I see are the monoflow tees that feed some emitters close to the boiler.

  I was referring to the tees in the near boiler piping diagram labeled " way to go "?

mattmia2

I dont think there is any reason to change the returns beyond replacing the circulators with a section of pipe and maybe a balancing valve. You can put a dirt mag discal in the supply before the circulator.

I had questions about pipe sizes but that was before I realized it was a center fed loop.

A circulator with enough flow for the monoflow will be important.

sixplex

mattmia2 said:

I dont think there is any reason to change the returns beyond replacing the circulators with a section of pipe and maybe a balancing valve. You can put a dirt mag discal in the supply before the circulator.

I had questions about pipe sizes but that was before I realized it was a center fed loop.

A circulator with enough flow for the monoflow will be important.

I read in the Q and A for monoflo split return drastically reduces the size of the "longest circuit".

Do the subzones for each of the 2 returns i have count as such?