Can’t get upstairs radiator to bleed or make heat!

Cummins17

I’ve been working on bleeding this radiator for over 4 hours now. It’s a 5 zone boiler heat system with baseboard radiators. All plumbed in 3/4 inch copper and some sort of pex. All the other zones are working perfect. 

Can’t get any heat going upstairs. So far I replaced the zone control valve and the thermostat and have confirmed both those work properly. I started to bleed by isolating the zone and turning the boiler off and allowing it to cool. Attaching a hose to the drain valve. Closing off the returning and opening the drain. Adjusting water pressure as needed. 

First couple bleeds I was able to get about a 1/2 gallon out and tons of air. Like makes the hose jump around it’s so much air. Then it just trickles. There is a bleeder upstairs in the middle of one of the returns. I have been able to get a decent amount of air out of it as well. 

Do I need to be more patient and just keep doing this very slow bleed process and eventually I will get full flow? Or is there something else I need to be doing? 

I believe the reason this happened is last year the circulator pump housing failed and had a pin hole shooting water out. It was replaced. But this zone doesn’t get used much as we usually have a fire going in the woodstove that heats the upstairs too good. 

Pictures are incoming as well. 

leonz

Turn the thermostat way up and keep water moving and the air will come out.

Cummins17

leonz said:

Turn the thermostat way up and keep water moving and the air will come out.

Like turn the thermostat on the boiler way down and the circulator pump will force it all out? 

hot_rod

Is there a working pressure gauge in the system? What does it read before and during the purge

leonz

NO, you need to open a few windows, turn the wall hung thermostat to the highest temperature to get the system very hot to drive the air out.

Cummins17

hot_rod said:

Is there a working pressure gauge in the system? What does it read before and during the purge

Between 12-15psi. I’ve been pushing up to 25psi while purging though. 

Cummins17

leonz said:

NO, you need to open a few windows, turn the wall hung thermostat to the highest temperature to get the system very hot to drive the air out.

I will try this now. How long should I let it go? Should I shut the other zones thermostats off or are they ok? 

pedmec

how high is the troublesome radiator from where the feed valve is connected to the heating system ?

Cummins17

pedmec said:

how high is the troublesome radiator from where the feed valve is connected to the heating system ?

Probably about a 30 foot run of pex. 

Cummins17

pedmec said:

how high is the troublesome radiator from where the feed valve is connected to the heating system ?

 Sorry I read that wrong. Height wise it’s probably about 15 feet above the feed valve in the basement 

Cummins17

Cummins17

neilc

with your boiler and circs turned off,
if you go to that high radiator, and crack open that vent, do you get and maintain water or air pressure?
in other words, is your feeder feeding consistant?

Cummins17 said:

Can’t get any heat going upstairs. So far I replaced the zone control valve and the thermostat and have confirmed both those work properly. I started to bleed by isolating the zone and turning the boiler off and allowing it to cool. Attaching a hose to the drain valve. Closing off the returning and opening the drain. Adjusting water pressure as needed. 

First couple bleeds I was able to get about a 1/2 gallon out and tons of air. Like makes the hose jump around it’s so much air. Then it just trickles. There is a bleeder upstairs in the middle of one of the returns. I have been able to get a decent amount of air out of it as well.

your maintaining 20~25 psi while purging?


or how bout this,
zone valve,
you do have it open and latched by the manual lever, correct?

and all the other zones are isolated while you're purging this one (?)

Cummins17

neilc said:

with your boiler and circs turned off, if you go to that high radiator, and crack open that vent, do you get and maintain water or air pressure? in other words, is your feeder feeding consistant?

Can’t get any heat going upstairs. So far I replaced the zone control valve and the thermostat and have confirmed both those work properly. I started to bleed by isolating the zone and turning the boiler off and allowing it to cool. Attaching a hose to the drain valve. Closing off the returning and opening the drain. Adjusting water pressure as needed. 

First couple bleeds I was able to get about a 1/2 gallon out and tons of air. Like makes the hose jump around it’s so much air. Then it just trickles. There is a bleeder upstairs in the middle of one of the returns. I have been able to get a decent amount of air out of it as well.

your maintaining 20~25 psi while purging? or how bout this, zone valve, you do have it open and latched by the manual lever, correct? and all the other zones are isolated while you're purging this one (?)    

That bleeder is actually towards the end of the loop in the upstairs zone and is the only bleeder. It seems to be pretty consistent after bleeding it for while. 

Zone valve is latched to manual when bleeding. I don’t maintain 20-25psi it drops off and returns to normal. I can feel water moving through the feed line it just isn’t making it all the way thru the radiator. 

neilc

I don't see your fill valve, but, usually they all have a way to fast fill,
it may be an obvious lever on the valve body,
or at the top diaphram bell housing, it will have a hole in it where you can insert a pry driver, and push down on the regulator mechanism,

you need to maintain pressure, 20~25, while purging or the air just stays up top,
the pressure and water speed push the air back down to your purge bib,
show your fill valve.

Cummins17

neilc said:

I don't see your fill valve, but, usually they all have a way to fast fill, it may be an obvious lever on the valve body, or at the top diaphram bell housing, it will have a hole in it where you can insert a pry driver, and push down on the regulator mechanism, you need to maintain pressure, 20~25, while purging or the air just stays up top, the pressure and water speed push the air back down to your purge bib, show your fill valve.

Here’s the fill valve. I’ve been turning the lever up and it increases the pressure. Should I leave the bleed valve upstairs open while purging air? Or just bleed from basement? 

neilc

I would not leave a bleed valve open and walk away, could get messy,
if you maintain pressure at the rad bleed valve then the setting on the fill valve, and it's operation, seem ok,

use the fast fill lever and maintain the higher pressure while you're in the basement at the purge bib,
zone valve manually open, and isolate ball valve downstream of purge bib,
purge till bubble free, and burp the ball valve below,
you should be maintaining a steady stream from the purge hose,
if pressure drops off there's something not being done right,

post a wide picture of the hose on the purge bib, and the isolation valve there,

Cummins17

neilc said:

I would not leave a bleed valve open and walk away, could get messy, if you maintain pressure at the rad bleed valve then the setting on the fill valve, and it's operation, seem ok, use the fast fill lever and maintain the higher pressure while you're in the basement at the purge bib, zone valve manually open, and isolate ball valve downstream of purge bib, purge till bubble free, and burp the ball valve below, you should be maintaining a steady stream from the purge hose, if pressure drops off there's something not being done right, post a wide picture of the hose on the purge bib, and the isolation valve there,

Hose bib and ball valve. Ball valve is currently closed. Waiting on the boiler to cool down to prevent damage from cold water rushing in. 

Cummins17

Cummins17 said:

neilc said:

I would not leave a bleed valve open and walk away, could get messy, if you maintain pressure at the rad bleed valve then the setting on the fill valve, and it's operation, seem ok, use the fast fill lever and maintain the higher pressure while you're in the basement at the purge bib, zone valve manually open, and isolate ball valve downstream of purge bib, purge till bubble free, and burp the ball valve below, you should be maintaining a steady stream from the purge hose, if pressure drops off there's something not being done right, post a wide picture of the hose on the purge bib, and the isolation valve there,

Hose bib and ball valve. Ball valve is currently closed. Waiting on the boiler to cool down to prevent damage from cold water rushing in. 

Cummins17

Got one big burst then it’s slowed to a trickle. I am using the fill valve to maintain 20-25psi. All zones closes except upstairs. Hose is on drain bib and valve is shut past drain bib. 

neilc

we're missing something here somewhere,
for giggles, open all your zone valves manually and latch,

and post a picture or 2 of the circulator, does that have a flow check in it?
Are there other flow checks or check valves we're not seeing?

neilc

wait, "slowed to a trickle",
but is there air pressure coming down ?
finger over the hose end, pressure?

neilc

any chance the pex got kinked anywhere ?

Cummins17

neilc said:

wait, "slowed to a trickle", but is there air pressure coming down ? finger over the hose end, pressure?

No air pressure. I think I am going to cut the feed line and plumb a bib into it and try to fill thru it and force the air out that way. 

hot_rod

Seems like you are flowing the wrong direction at the purge cock. Water should go up, around the zone, stop at the ball valve and purge air at that point. Do that for every zone.

Cummins17

hot_rod said:

Seems like you are flowing the wrong direction at the purge cock. Water should go up, around the zone, stop at the ball valve and purge air at that point. Do that for every zone.

I was able to bleed every other zone like that. 

hot_rod

If the other zones purge properly, it sounds like a restriction somewhere. Closed or backwards zone valve? Ball valve not open completly? Kink in the tube somewhere?

certainly not frozen this time of year

neilc

sometimes TRVs are fitted into baseboards under the covers, I don't know why,
any chance you have a TRV up there somewhere that is clamped down ?

Cummins17

I am back up and running. Plumbed a hose bib into the feed for that zone and forced water in. Pushed out tons of air. Flushed 4 5 gallon buckets out of it and it finally got all the air and old water out. Probably going to plumb these into the feeds of all my feeds and try to flush them every fall. 

Thanks for all your help!

neilc

I'm still wondering what was holding back in the direction of flow,
congrats on heat

HydroNiCK

Hook hose up to the zone and open it up. You keep using fast fill anyway athis point blast it with your hose.

Cummins17

neilc said:

I'm still wondering what was holding back in the direction of flow, congrats on heat

I think it was just hydro locked and needed a little extra force.