Bleed from manifold?

donedeal

Is there a fairly simple way to bleed air from the top manifold in this picture ? The zone was not heating adequately, the temp was only reach about 110. The circulator was making a little rattling noise. I tried changing them circulator and now it’s worse, not picking up temp at all. And the manifold below is reaching higher temps than usual. The Hvac came out and was certain there’s air in the line but couldn’t figure out how to bleed it. Ultimately he said he had to order a valve that he would put in on the return line down in the basement near then boiler next week. But is there a simple way I can try to bleed direct from the manifold ?

STEVEusaPA

Don't you have a bleeder on the top left where the barbed fitting is. Put a hose on the fitting, open the valve.
Note how many rotations on each loop, close all 3, open one at a time to bleed. Someone may have to be at the boiler to operate the fast fill to keep enough water in the system and to make sure the pressure does rise enough to pop the relief valve.

hot_rod

The Watts website has some additional info. You have both a purge valve and a small bleeder on that manifold. Find a hose that slips on that barb as you will need to flow a lot of water to purge each loop one by one.

donedeal

He tried that but I’m not sure that he closed all three loops and tried one at a time. Nor was there someone in the basement at the fill. Is this the fast fill? So just have this on while draining the manifold? Do I need to shut off/isolate any other pumps or valves elsewhere ?

hot_rod

So you close the blue tee handle valve on the return, but leave the red one open.

Then screw down all but one of the blue plastic caps, that shuts off the loop flow. Purge the one open one until it runs clean. If you purge into a 5 gallon bucket you can better see when all the small bubbles disappear.

That is probably a metric hose thread under the barb fitting, find a piece of hose to slip over it, maybe use a hose clamp.

I like to use a clear vinyl hose for purging to see the air coming around, buy it at plumbing or hardware stores. Take the barb fitting with you to get the correct those, maybe 8 feet.

Of course if you had a Caleffi fill valve you would not need to babysit it, it is a fast fill valve by design

donedeal

Okay thanks so in the marked up photo below of the manifold , just stick a clear hose on that red circled part and twist open the green circled part with the other components as open/closed as marked while simultaneously running the fill nonstop. Should I have the circulator running ?

Do I need to close any valves anywhere else in the other picture ? The red circle is the circulator pump for this manifold.

How do I know how much water to add via the fill ? Will that overpressure the other zones or by physics will the water go to the areas of lowest water supply? when would I stop filling? When I get a clean stream of water out of the hose I’m thinking ...

Sorry for the questions, I’d have the hvac do it, but they couldn’t figure it out and want to cut into the system which seems unnecessary.

hot_rod

Correct, almost. I think the white plastic part is just a small bleeder, does it have a screwdriver or square key in the center? Open carefully and it will probably squirt from a small hole.

That barb connection works like a garden hose nozzle, when you turn it, it opens a port and allows flow. Don't unscrew too far or it ends up in your lap

A second person will need to monitor pressure back at the boiler and keep it from going to 30 psi as you open and close the various manifold blue valves, or the boiler relief will pop.

The fill will be adding the same amount you are purging out, maybe more so you need to watch pressure.

Shut down the boiler and pumps while purging.

When all loops are air free, release the fast fill lever, pressurize to 12 psi, start system.

It can take a few- 5 minutes per loop to get them air free, so you have a few hours ahead of you.

donedeal

huh, when I open the drain valve at the manifold all the way nothing comes out. No water, no burst of air. I engaged the fast fill and get psi up to 25 but didn’t want to go past that and still no water with one open and the return closed .

I tried changing the circulator on chance it could be faulty, it’s definitely a little noisy. I opened the right ball valve adjacent to circulator just to see if there’s water in there and a blast of air came out and some spurts of water but not much else. But I don’t know if that’s normal. It doesn’t get warm in the tubing just past the circulator but is hot right up to it and within the circulator. Could there be an air blockage more proximal to the manifold ?

Any thoughts?

donedeal

I got in touch with the previous owner and he recommended this -

Close the shutoff, both the red and blue valves.

Open the drain and let any water come out.

Take off the end cap and put on the hose connection (pic attached) , hook up a hose to it

leave the drain open, and run fresh water through the system, look for big air bubbles coming out.
When its a steady stream of water, shut the hose connection, and then shut each individual supply and return line, so all the water will be stuck in the tubing. Reinstall the end cap. Open the individual supply and return lines. Open the blue and red shutoffs

hot_rod

that is intended to test the manifold and loops before it is piped in, a way to pump water into the loops

do you get water and pressure out of the white bleeder on the supply manifold

donedeal

Nothing comes out of that white bleeder

hot_rod

usually a system only needs to be bleed one time, makes me wonder why you need to bleed it again and that then owner had a "method"

If you cannot get flow from the red manifold, thru then loops and out the blue purge with the fill pressure at 25 psi, it must have something else wrong and it probably will not heat even if you do a manual purge with that test valve.

25 psi is a lot more that the circulator will develop.

How old is that system. That rubber has been know to sludge up.
Maybe it has the mixing valves sludge shut?

There is a hose bib where the fill line ties into your system, you could hook a garden hose there and use city pressure to purge, but you would need to isolate the boiler out bon then loop or the relief will pop.

donedeal

K. It’s about 8-10 years old, I’ve been here for 3. Had to replace three different circulators in that time and poor heating in the bathroom/basement zone but otherwise has been fine.

Just odd that temps were only reaching 110-120 on this bad zone a couple nights ago when usually it’s 140, so I decided to try to change the circulator and then bam, no hot water at all thru the zone.

Gordy

Are you sure there isn't some valve(s) off to that zone?

Gordy

Also those two circs that are vertical should not be mounted in that way unless pressure is around 25. It holds air in the pumps volute and will also lack lubrication.

hot_rod

anytime you pull a component out, there is a chance to get an air lock, purging, however you do it should get flow going.

No system should go thru circulator that often, what is the failure, gunked up? Frozen impeller?

The upper two pumps are improperly installed, the motor needs to be horizontal. Mounted that way could cause premature failure as fluid may not be getting to the bearing and cooling the motor.

Looks like someone only had rotated flange versions to install? Notice the difference between the upper and lower pumps, motor to flange orientation.

It could be the mix valve that's causing the low temperature condition also.

donedeal

I’ve triple checked no valves closed. It’s also weird that now the manifold below it is hitting supply temps of 160 return 140 where usually it’s 20-30 degrees less than that on each.

After That first night I swapped the circulator out, put the new one in. It didn’t seem to be working so I ripped/broke the integrated restriction valve on the right hand side out of it Then reinstalled and it was moving water (backwards maybe, draining the zone- is that even possible??)

ive since put the original circulator back in but nothing is moving still , and still getting that whining noise from it. Could both pumps just be bad ? Doesn’t explain why raising the psi doesn’t flow water tho or why no water comes out of the drain valve, unless it pumped all water out of the zone ?

Gordy

When you removed the circ what was the system water like?

I'm thinking you have some fouled components like @hot rod_7 .

Specifically the mixing valve.

Gordy

The circ in question is also at the highest point. Most likely air locked by your description.

hot_rod

If the pump is whining it probably isn't moving fluid. With the motor vertical that is another possible cause of noise, no fluid lubricating the bushing on the motor.

All pumps have direction arrows cast in, I doubt it can move water backwards if the flow arrow is pointing towards the system.

You need to get a good purge to get back to square one on the system, pumps don't pump if you are air locked, and they can and will burn out if not moving fluid.

donedeal

Murky water. When the other pumps failed I changed them to the flanged version so they could fit in proper position , I’d read that before. Didn’t have one on hand to try this one.

I’ll get a flanged circulator to install but then how do I proceed with getting a good purge ? Isolate out the boiler and hook the whole rest of the system up to city water and run it thru or try what the owner said first? I’d be afraid of running pressure too high and busting a fitting somewhere ! I’ll run this by hvac on Monday tho, I think this is out of my DIY league at this point.

Could something be busted in front of the circulator preventing it from filling and pumping?


But worst case hvac wanted to install some valve near the boiler to purge, that sounded expensive, is it unnecessary?

hot_rod

Looks to me you have plenty of places to purge the system properly, and additional valves to use house pressure. There are boiler drain, hose bib connections all over that system, the black handled valves. A wash machine hose would connect the to the house water system power purge.

I suspect someone has done this before to have those additional valves installed?

The "art of troubleshooting" start with the most obvious, and work your way around the system. A good hydronics guy should be able to figure out how to power purge the entire system, boiler, piping, and individual loops at the manifold.

donedeal

Ok I’m gonna take one more crack at this tomorrow morning, it kills me not to be able to figure it out.

- could there be a more “hidden” valve that shut off that I don’t know about ? Like could one of these be something that closes under different pressure situations if I messed something up and is now preventing flow ? (Circled in green)

- if airbound, could I do a full purge by hooking a garden hose up to spigot circled, run it open and manually fast fill until for until it seems to run clear while maintaining psi under 30? Can I mess anything up by doing this as long as I keep that pressure under 30?

hot_rod

Looks like that 3 way thermostatic valve could use a cleaning and rebuild, it could be clogged, also. Three way valves cannot be turned off, as one port closes the other side opens. They do have small passages that could clog up, however.

The other two valves are one direction flow checks. Normally the stem is turned down, clockwise. You could turn them counter clockwise which forces them open, and easy thing to try.

From what little I can see I don't notice any valve that is turned off to prevent flow to the manifolds.

Rubber tube systems have a history of clogging up the tube and components. Often a good high pressure flush will clean them out.

But it takes more than the 25 psi fill pressure to blast any sludge out.

A purge pump providing high flow and high pressure is sometimes needed, or valving out the boiler and flushing with 45-60 psi water pressure.

There are purge cocks all over that system, a red handle ball valve with a hose bib valve next to it. But you would need to do a section at a time, it's tough to purge and entire radiant system with just 1/2 valves.

You kinda need to be standing in front of that wall to decipher which isolation valves need to be open and closed, and also activate one or two loops at a time to get everything purged.

There should always be water and pressure at those small bleeders on the two manifolds. Of course those could be plugged also.

Richard out in Colorado rehabs those rubber tube systems, sometimes
He has purged 1/2 of a 55 gallon drum full of crud from some systems. Others refuse to budge and the loops are abandon.

I don't think you are there yet, your tube is not all that old, based on the color black.