Boiler system help! Cannot get heat to all registers...
Hello, I recently replaced my expansion tank (wouldn't hold pressure) and my temp/pressure gauge due to a leak. I've been trying get the air out of my system since with no luck. It's a single story home and not all registers are getting heat. I've tried purging air from both zones as I only see two valves to close a loop. The large yellow handle near the boiler is closed when I do it, and I've tried draining from both the high and low spigots. Also tried not closing anything and did the whole system. Frustrated. I'll attach pics and hope somebody can give me some insight. Thanks.
Comments
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The blue handle valve that is circled must be closed as well as the yellow handled valve.
You have two loops and they must be purged separately.Connect a hose to the boiler drain to the right of the blue handled valve while it AND the yellow valve are closed. Purge it until only clear water water comes out. Close the boiler drain and move the hose to the other boiler drain above the yellow valve and do the same. Do not open either the blue or yellow valves until the air is completely purged.
I’ve also circled the system fill valve which has a lever on top. The valve is probably set to maintain 12 psi on the system, but that’s usually not enough when purging air. Raising the lever will manual open the valve and allow full house pressure to be used for purging.
CAUTION: the system pressure must NOT be allowed to get to or near 30psi on the boiler gauge with the fill valve manually open or the boiler relief valve will release dumping out water! I’d keep it at 25psi or below.
Once all air is purged from both loops, close the boiler drain and the fill valve. If the system pressure is above 15 psi, then let some pressure off through one of the boiler drains until it drops to 15.
Open the blue and yellow valves and you should be good to go.
Bob Boan
You can choose to do what you want, but you cannot choose the consequences.1 -
Ok, thanks for the info. Pretty sure I've done it that way, but I'll give it another go. Probably emptied a 5 gallon bucket about 25 times. Haha! Water is clear, but still not working. Try again tonight.
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Should the valves be wide open or just cracked 1/2 way or something?
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Wide open.
Hose into a floor drain may expedite things.
Trying to squeeze the best out of a Weil-McLain JB-5 running a 1912 1 pipe system.0 -
Additional info about your system.
Your expansion tank is known as a Fil-Trol system. It is not the regular expansion tank that @Ironman believes it might be. That expansion tank is also the trigger for the automatic water feeder (in the Red circle) so you will never get the water pressure you need to flush that water out of the loops. You will only get the water pressure to go as high as the air pressure in the tank
It also appears that you have no other bypass valve to add any higher pressure to the boiler. So the highest pressure that will ever be applied to the boiler will be the air pressure charge in the tank (usually 12 PSI). That may be enough to purge a one story baseboard loop depending on the configuration. But it may not be enough for the 1" loop. (might be 1-1/4" copper)
Which brings me to the next question, the 1" loop… What type of radiators do you have on that side of the house? It looks like you may have other than baseboard radiators. and there is a 1-1/4" tee fitting just past the Red Flo-Control valve just before the 1-1/4" x 3/4" Tee fitting for the baseboard loop.
If you have Convectors then each convector has an air vent on them that needs to be bled individually. Those vents might be behind the radiator covers.
Need pictures of the different radiators in your home.
Edward Young Retired
After you make that expensive repair and you still have the same problem, What will you check next?
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Good eye Ed. I didn’t see that. It looks like there might yet be another one tapped into the supply line below where it branches to both zones?
It makes it difficult to explain to a HO when the system’s been knuckleheaded.
Bob Boan
You can choose to do what you want, but you cannot choose the consequences.
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Agree @Ironman. there are at least 3 different loops off of that supply tee run. There may be even more tees from the pipe the turns up from that 1-1/4" tee branch. So the entire home may be several parallel loops of "Series baseboard" which means that there might be more of those purge stations in the basement somewhere.
only see one feed line though
Another option is that the other loops only have isolation valves and use the purge station (near the yellow valve you referred to originally) as a common purge. One other observation would be that the original boiler was oil fired with a tankless coil. See the B&G Flo-Valve… with the manual open stem all the way up? No need for that if there was no tankless!
Edward Young Retired
After you make that expensive repair and you still have the same problem, What will you check next?
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Wow, lots of good information. Thanks guys. Some more info for you...all the registers are baseboard. I've destroyed plaster in the past taking end caps off looking for bleeders. I found 2 in the whole house. One in my kids room and the other in our office. The expansion tank I just replaced, was the exact product number as I took off. Yes, this house use to be oil fired. When it was switched to propane, years before I bought it, they also replaced the furnace. Probably some of the piping also. Some of it is copper, the other is steel. I've had hvac techs out in the past, and nobody has really got this working correctly in my opinion. Some registers are hot, some warm, others cold. I've bled ot in the past with some luck, but not this time for some reason. It seems to be cobbled together...probably the reason myself and hvac guys can't ever get it working right. Not a fan of this type of heat and always dread winter. Haha! Like I said, gonna try again tonight and will follow your suggestions. Anything else is appreciated!
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Most folks with wet heat love it. you just need someone that can get the air out.
Here are some tricks. You need to get the water pressure in the boiler up to about 25 PSI. this may compress the air in the system enough for the circulator pump to move it out of the way and back to that air vent on the top of the scoop where you put your new tank. In order to do that you need to connect a garden hose from a cold water tap from outside or from the washing machine hookup. Then you will purge all the air from the hose into a bucket (you don't want to add more air to the system) then connect the hose with the air removed and full of water to the boiler drain valve and watch the gauge as you open the valve and let water in.
When it gets to 25 PSI on the gauge, shut off the water from the hose by closing the boiler drain. Disconnect the other end of the hose from the tap and place the hose on the purge valve near the Yellow handle valve. Be ready to lower the boiler pressure if the gauge goes above 28 PSI so you do not pop the relief valve. Operate the boiler to get the pump to start to push water thru the system. Lower the pressure by opening the purge valve to let a little water out. If you get lucky, some of the air in the radiators will find its way back to the boiler and end up in the air scoop where the air vent will let it out. If you get air out of the vent that will lower the boiler pressure so you want to keep as much water pressure in the boiler as you can during this purging process.
In order to force water to go in the other zone loops, close the Blue valve you use to purge that one loop. this will make the pump push water thru the other loops.
Look for other valves on the other zone loops to see if they can be isolated. Just understand that the water will take the path of least resistance. If there is a tee fitting and you push water into one of the openings, the water will go out of that tee fitting based on what is the least resistance path. If the path it is not taking has an air pocket then there is nothing you can do to make it go that way unless there is a valve on the side that has less resistance. Close it and make the water go the other way.
Diagram to follow
Edward Young Retired
After you make that expensive repair and you still have the same problem, What will you check next?
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I think you really need to get rid of that fill-trol tank in favor of a regular #30 expansion tank. You will never be able to purge the system properly with that in place. The good news is that you already have a pressure reducing fill valve. Most system with a fill-trol tank do not have one.
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Would raising the pressure in the expansion tank (currently 12 psi) help me in this case? I've read where it might...
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Ugh, I just replaced it. Should of researched a little more first I guess.
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Don't worry about that tank. it is just fine.
Don't raise the pressure in the tank
From what I can see here in the photos you posted you may have some valves that you do not know about.
Take a look at the return pipe on your heater and follow it away from the heater to see if there are any other valves where the large pipe Tee fitting to small 3/4" is connected.
You can get the pressure higher than the FillTrol by using a washing machine hose connected to thewater heater drain and the boiler drain. with both (A) valves open you will getthe pressure in the boiler up, watch the gauge ans shut off (A) when the pressure gets to 25 PSI.
You have a valve marked B in a green oval in the photo. You want to look at the return pipe to the boiler and follow it away from the boiler (darker Brown in the illustration) to see if there are other Tee fittings that have 3/4" pipes connected. see if there are any B type valves on those return lines. If you can find all of them then you can purge all the loops.
Let me know if you can find any more B type valves on your system.
You should be able to click on the illustration and zoom in for details.
Edward Young Retired
After you make that expensive repair and you still have the same problem, What will you check next?
1 -
Thank you very much for taking the time to respond and make that diagram! There is only one more t with shutoff that I see. It's looks pretty rough, but it's to the left of the furnace. It is the 2nd pic posted in the original post.
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Got it!
Look farther down the pipe (green arrow). What is connected to that pipe? More radiator loops branch off before it ends. How many more? or is this the last loop? If it is the last loop then you have 3 different loops and and you need to find one more valve. It might be on the supply side of that loop.
once you can isolate all three loops, then I can tell you how to purge it.
As it stands now, you can only purge two of them with what I know so far.
In the second (B) valve above, is there a purge vent (that you can connect a hose to) like there is on the first one in the top picture?
Edward Young Retired
After you make that expensive repair and you still have the same problem, What will you check next?
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The pipe just goes off by itself and then I lose them all behind walls and metal covers in the basement.
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I just remembered this...in the one corner of my basement is a small closet. I may have found the 3rd drain. There used to be heat in my garage until the pipe burst. We eliminated it and the baseboard (cut the whole pipe out and just continued the loop with a small connection). There are valves and a spigot just inside the basement where it used to go to the garage. Problem is...nothing turns. You will see in the pic how bad they are. Been meaning to get a plumber out to replace all of them. So, maybe I can just try the 2 loops and see what happens...
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didn't see it mentioned but are there any bleeders on the radiation?
John Ringel Energy Kinetics0 -
I've found 2 in the whole house on the baseboards.
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OK now that you have all three valves located I will go from your basement diagram
To a diagram that shows your system in a little easier to follow diagram that I used to teach a seminar about this. the parts are not in the same order so I will need to adjust then a little.
- So connect the water heater drain to the boiler drain with a double female end hose or a washing machine hose as indicated in the top photo/illustration.
- Open the water heater drain and be sure that you get good flow before you connect to the boiler drain. (and you water heater needs to be flushed anyway)
- With the air purged from that hose connect to the boiler
- Open the water heater drain valve to add pressure to the hose
- Close all three of the (B) valves on your system
- Close the yellow handle valve on your system
- Connect a garden hose to the purge tap just above Yellow valve
- Now open the boiler drain valve to let pressure in the boiler. Watch the gauge and be ready to shut off if the pressure goes over 25 PSI
- Open one of the three (B) valves in you system and open the purge valve to let the water and the air out.
- After a few minutes you will notice that no more air is coming out
- Then close the open (B) valve and open another (B) valve and wait for that to purge all the air.
- Repeat with the third (B) valve with the other two (B) valves closed.
- when all the air is out close the boiler drain and the purge tap.
That should. get all the air out. Now you need to get everything back to normal.
- Close the boiler drain at the bottom.
- Close the water heater drain
- Disconnect that hose.
- Open all the (B) valves
- Open the Yellow valve
- Look at the boiler pressure and let water out of the purge valve until you get to 12 PSI
- once that is done, you can close the purge valve and disconnect that hose.
- Operate the boiler and see how it heats the home.
Edward Young Retired
After you make that expensive repair and you still have the same problem, What will you check next?
1 - So connect the water heater drain to the boiler drain with a double female end hose or a washing machine hose as indicated in the top photo/illustration.
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I'll give it a shot! Thanks again.
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The only reason that valve is there is because that branch loop has been an issue in the past. Good catch.
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@HVACNUT Said: "The only reason that valve is there is because that branch loop has been an issue in the past. Good catch."
Is this one that you have been to?
Edward Young Retired
After you make that expensive repair and you still have the same problem, What will you check next?
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Lol, no. But I have seen a couple over the years while poking around. I saw one with a drain valve also for a purge station.
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Update: Like I mentioned when I posted a pic of the last shut off valve, it will not turn. Thing is so stuck the handle broke. So I just kept trying to bleed air using the other 2 valves. Pushed a ton of water through it. Fired it up tonight and same thing. Not all the baseboards are getting heat. The pipes are all scorching hot to touch in the basement. Every single pipe going every single way. I don't get it. Pretty frustrated with it and about ready to call a hvac tech. Unfortunately around here, nobody knows boilers. Been through it already in the past. Probably need to replace all the shut off valves and hope I can get heat. Thanks for all the help, but I think I've done everything I can do.
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Have you bled the radiators?
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Yeah. Only 2 bleeders on all the baseboards.
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What? On a Monoflo system, every rad gets a bleeder. The original design didn't have a purge station at the boiler.
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Could it be that you have a bad circulator while we’ve all gone on the assumption that you had air binding?
Bob Boan
You can choose to do what you want, but you cannot choose the consequences.
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Yes sir. Mentioned earlier in the post...I destroyed a decent amount of plaster getting these end caps off in the past to check for bleeders. 2.
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Possibly? Any way to check that? I can hear water going through the pipes when it's running...So I assume it's circulating?
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if you hear your water, there's air there too
known to beat dead horses
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Wish I could post a video. When I purge it, water is gurgling in the pipes, there is air hissing out of the relief valve on top of the expansion tank and no bubbles at all in the bucket. Haha! Unreal. Again, thanks for trying guys. This thing is a nightmare. I'm done with it for now.
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I've never seen a Monoflo system that didn't have some means of bleeding each convector, radiator, fin tube baseboard, whatever. Every branch loop I've ever seen in my life had a bleeder at the emitter.
Can you post pics?
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Here is an example. In our bathroom which was remodled and has a different cover, so it's easy to get off. Pic of both ends, no bleeders, and a pic of the whole thing.
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The remodeling was probably when the modifications were made and the coin vents removed. Maybe the system was originally radiators and foolishly changed to fin tube?
You replace one of the copper 90⁰s on each baseboard with a brass 3/4"x1/8" heel tee and install coin vents or install a full port ball valve on the monoflo main between each baseboard element.
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The baseboards were not changed in the remodel. All the registers are the same as they were in 1968 when the house was built. It was my grandfathers house. My dad grew up here (I've been talking to him about this), I spent my childhood here, now I own it. I just have some sort of mutant system.
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Do we know for certain that this is a Monoflo system?
Can you take a couple of pics of the Tees where the baseboards branch off the main?
Bob Boan
You can choose to do what you want, but you cannot choose the consequences.0 -
Not much I can see downstairs. Most of the pipes are covered with a metal shield that is nailed to the wall. The few I see just go straight up through the floor.
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no, they want to see where the other end of those feeds connect to the basement main also
known to beat dead horses
2
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