Hydronic heat, I broke it.

[HillStreet]

Find the highest point in your new change and remove the nipple that is there and install a bleeder nipple.

 

[oosik]

Ah - ha. There are multiple loops in this heating system. You have just added restrictions in this loop. As "the OldGrind & LouNY" indicate - you will probably need flow restriction valving to get adequate flow back into this loop. Even inside a closed circuit - water will take the path of least resistance.

 

[widefat]

Two more drawings -

 

[oosik]

WF - is that bottom drawing correct? You have a main loop( heavy black line) with a circulating pump in the loop. Each of the radiators is a separate loop off that main loop? How does water flow out and thru each of the individual radiator loops?

 

[widefat]

WF - is that bottom drawing correct? You have a main loop( heavy black line) with a circulating pump in the loop. Each of the radiators is a separate loop off that main loop? How does water flow out and thru each of the individual radiator loops?

Yep.

System #2 - Hydronic Piping Systems – Fraser Engineering

 

[dlctcg]

Just wondering after you cut, drained, installed the new radiator & piping; how did you initially refill & bleed that loop?

I'm assuming your one pipe system uses Diverter Tee's (MonoFlow Tee's) in it at each radiator loop off the Main System loop. This system is much tougher to bleed when air is trapped in one of the radiator loops. Using just the bleeder vavle in the radiator loop my never work or take an extremely long time to bleed. Water will take the least pass of resistance & with an air lock in that loop most of the water will flow past the Diverter Tee & travel straight through the Main System Loop.


This may help:

(1) If you have the ability to shutdown each radiator loop off the main loop I would shut them all off first (your system may not have this)
(2) Then shutdown the Main Loop Return
(3) Then Open the Bleed Valve on the radiator loop you just modified
(4) Slowly (SLOWLY) add water to pressurize the loop forcing the air through it.. You don't need the boiler running to do this...

Go slow... these system take awhile to bleed... after you think you have most of the air out of that radiator loop Close that loop also

With ALL of the radiator loop closed off the Main Loop - Bleed the main Loop again..

Then fire the boiler & have the system call for heat... I would then carefully open & bleed each of the radiator loop again individually...

 

[CalG]

With mono-flow tees at each diversion, the newly installed drop will likely never self bleed or purge the trapped air.

If diverter tees are NOT fitted, it's worse '-)

There are no shut off valves shown in the system layout. That sucks. because if the flow could be forced through the modified loop, circulation could be restored. At least until "new air" gets caught in the natural trap.

A simple bleed at each elbow of the modification might be enough to get things moving through the loop.

I can't think of a reason to use caution or to go slow with your efforts. but don't expect immediate improved results without getting in and making changes.

Diverter tees are stupid devices.

 

[kenmac]

I agree, Most likely got an air lock in the system

 

[Tractor Seabee]

This stuff was my trade for 30 years. Probably an air lock but! I would never try to diagnose this without seeing the system. An air bleed needs to at every high point of the system. I would need to see the finned pipe enclosure to determine how to accomplish such. Air does not circulate in a closed system as it pockets in the high points blocking flow. Bleeding a cold system is a start, heating the water releases the dissolved in the water until there is no more. Several bleedings may be required to get rid of it all. Your drawing exhibits at least one bleed valve in the wrong location, maybe. We used to tip the finned pie a little down toward the input side to push the air to the outlet connection.

Zone pumps and closely spaced tees or diverter tees help smooth out a system(s). Engineering on these systems has gone through a lot of changes over the last 30 years. Like is your boiler make-up water feed automatic or manual? A leaky system keeping water flowing in on an auto feed also keeps introducing air and nobody notices like on a manual feed which shuts down on low water. Continuous water feed will also shorten the life of the boiler and components due to oxygen created acidic corrosion among many other potential problems. The average homeowner has no clue about water chemistry and water treatment of hydronic systems.

You are possibly beyond the DIY stage unless you have a knowledgeable friend or neighbor. You may find some helpful system drawings on the internet. I gave a way ll that stuff long ago.

Ron

 

[BrokenTrack]

You need a high point vent. Home Depot sells them...