air in heating pipes

scottymac

just put a new gas boiler in my home... I have baseboard.. I also have a monoflo system ..After hooking up new boiler and bleeding all baseboards i still keep on getting bubble noises in my pipes in baseboards....WHY.... I have a taco0010 circ on my heat side..1 zone...

kcopp

0010... sounds

like a way too big a circulator. Are you pumping away from the expantion tank?

icesailor

Over Pumped Air:

Another over pumped system.

All the old monoflow systems that I ever saw or still see were pumped with a B&G Series 100 or equivalent, Which is is equal to a 007.

010's prove my point. If you increase the velocity in a pipe with a high GPM, you will cause a localized vacuum with cavitation and get air. The pressures in the system and the temperatures will make tons of air.

Some of you need to put tridicator gauges on your supply and returns so you can actually "see" what your differential pressures and your actual "Delta T's" are so you can maybe understand how badly you may be over pumping a zone or circuit.

"Ti's better to pump up than to have to pump down". So sayeth some.

icesailor

Pumping away:

And all those old Monoflow systems, used an air scoop with a can vent on top and the expansion tank hung on the bottom (badder tank) or off the top of the boiler with the circulators on the return so the cooler water didn't wreck the water seals on the 3 piece circulator.

The other day, I went to a new customer. He had no heat on the second floor. He had been through 3, 007's on this zone. All the circ's were on the supply. I told him he needed more pressure in the system. It was at 10#. I pushed it up to 20#, and the flow started. The 007 was cavitation in the hot system supply water causing steam/air to rise up to the baseboards. "You want me to vent the radiators (baseboards) upstairs?" says the customer. No, the higher pressure will squish the air and if you get any flow through the pipes, it will be absorbed, The water went cold in the return, and then got hot as the sound in the 007 changed. If the circulator was on the return, and there was no air restriction in the upstairs loop, the water would have circulated from the circulator on the return. Only if the top of the loop is negative, and the supply temperature going into the beginning of the top floor radiation is higher than the boiling point of the water, for that negative pressure, will there be boiling/ air.

The next day, I stopped by. "It's fine now".

Has anyone noticed how the boiler manufacturers are starting to show the boiler pumps on the returns so you are pumping into the boilers? Cooler water I suppose and the pressure is being pumped into the boiler.  

Any circulator that is on the return and is "seeing" negative pressures is pumping into a badly designed loop and the circulator is being used to overcome a problem. IMO.

Mark Eatherton

Got pictures?

A picture is worth a few thousand words around here....



Front, back and sides would be helpful.



ME

scottymac

air in heat pipes

I tried to use a 007 and it wasn't really pushing the water enough ..11/2 inch pipe around my basement and 1/2 inch pipes going up walls to supply baseboards ... OLD  homeowner real piss poor job too cheat to put in 3/4 pipe ..0010 was pushing water to 3rd floor ..20 feet up.. 007 was getting so hot couldn't even touch the motor side of circ....Scratching my head  on this ....

scottymac

air in pipes

 I have 20 lbs in boiler.. 007 won't push heat up to 3rd floor ..0010 does .007 was getting so hot couldn't even touch the circ motor

kcopp

hold on....

are you taking lines off the mono flow loop all the way to the 3rd floor? Thats not a good plan. You should have a separate zone. It will not "work" the way you have it 1st fl is over pumped.....3rd fl. has air issues.

icesailor

Pump Head Pressure:

>> I have 20 lbs in boiler.. 007 won't push heat up to 3rd floor ..0010 does .007 was getting so hot couldn't even touch the circ motor

icesailor

Air in pipes:

Are you using one circulator to try and push water around three floors at once?

You can't mix monoflows and series looped radiation on the same loop.

You need the hydronic equivalent to Steamhead et/al to look at this. It's too complicated to figure out without seeing it in person. If the previous homeowner did the work, it is probably FUBBAR and needs a serious consult with a pipe doctor.

add

Need to split

  the loops,i agree with ice.need to see some pic. of all the piping.