Banging noise.
#1
Banging noise.
Hi. I have an oil fired, forced hot water system, and lately been having some loud banging noise. It seems to be coming from the BG flo control valve. It doesn't happen every time there is a call for heat, but it seems to be getting worse lately. My first thought was maybe air in the pipes, but I can't find bleeders anywhere.
There are pics of my system in this old post from when I replaced a circulator pump taco circulator pump
I'm really not sure what to do. I'm worried.
Thanks for reading.
There are pics of my system in this old post from when I replaced a circulator pump taco circulator pump
I'm really not sure what to do. I'm worried.
Thanks for reading.
#2
Member
Best bet is to call a plumber. He can explain what you have and what you need if there is no way to bleed air from the heating system. Have him do the work if it is out of your comfort zone.
#3
Join Date: Jan 2005
Location: Delaware, The First State
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How much pressure is on the boiler? If low, increase it via the pressure reducing valve to 12-15#. Sometimes the reducing valves get crud in them & don't operate as they should. You may need to purge air as you did when you replaced the circulator.
#4
I will take a look after work. If it's low, do I need to let it cool down before operating that valve? Turn the system off?
Honestly, I have always wondered if I purged it correctly.
Honestly, I have always wondered if I purged it correctly.
#5
So, I went home on my lunch break, and took a look. It looks like about 17 psi.
I tried turning on one zone at a time, the downstairs zone was nice and quiet. Seemed to work normal. When I turned on the other zone, upstairs zone, the noise happened. Could I possibly have air in one only zone, but not the other? Could it be a circulator pump issue? It is the same zone that I replaced the pump on 4 years ago. The noise is rattling inside the BG Flo check. It resonates through the pipes.
When the circulator was not working someone advised me to open one or both (i can't remember) of the valves in this picture, and it basically made the whole house one zone. I wonder if I should try that again.
I tried turning on one zone at a time, the downstairs zone was nice and quiet. Seemed to work normal. When I turned on the other zone, upstairs zone, the noise happened. Could I possibly have air in one only zone, but not the other? Could it be a circulator pump issue? It is the same zone that I replaced the pump on 4 years ago. The noise is rattling inside the BG Flo check. It resonates through the pipes.
When the circulator was not working someone advised me to open one or both (i can't remember) of the valves in this picture, and it basically made the whole house one zone. I wonder if I should try that again.
Last edited by frankjc; 01-21-20 at 12:06 PM.
#6
Member
frankjc is probably right that banging nose is air going through B&G flow control valve in 2015 post picture. https://www.supplyhouse.com/Bell-Gos...oduct-overview
Venting air at boiler level is not always completely effective. Would try venting at high point of system. If no high vents, try loosening a fitting.
A temporary solution is venting with saddle valve installed at system high point. Eventually it should be replace with regular fittings. https://www.supplyhouse.com/Wal-rich...alve-Lead-Free
Venting air at boiler level is not always completely effective. Would try venting at high point of system. If no high vents, try loosening a fitting.
A temporary solution is venting with saddle valve installed at system high point. Eventually it should be replace with regular fittings. https://www.supplyhouse.com/Wal-rich...alve-Lead-Free
#7
I really can't tell. would the 2 zones need to be bled separately? Or are they connected? It seems to only happen when the upstairs zone kicks on. Then goes away.
The pump on the right is the "upstairs" pump, wich I replaced 4 years ago, and it's the one that comes on when the noise starts. That's actually the old pump in the picture.
The pump on the right is the "upstairs" pump, wich I replaced 4 years ago, and it's the one that comes on when the noise starts. That's actually the old pump in the picture.
#9
Also also the temperature in the boiler is 170 is that too cold you should be higher than that?
And and thank you all for your responses by the way I really appreciate it
And and thank you all for your responses by the way I really appreciate it
#10
180° is typical so 170° could be a tad low but that won't cause that noise.
170° water will heat the house a bit slower.
170° water will heat the house a bit slower.
#11
Member
As long as you are satisfied with the heat you are getting and domestic hot water if you have a coil that is fine. Your aquastat is adjustable if you want to experiment. Aluminum fin baseboard if figured at about 600 BTU's a foot at 180 deg. water for heat output.
Example would be if your figured room comes up with 6000 btu's of heat loss it would take 10 ft. of baseboard with 180 deg. water running through it to heat that room. That would be 600 btu's x 10 ft of board. The higher the water temp., the more heat the baseboard puts out. The lower the temp, the less heat it puts out.
This is for typical #30 baseboard. They also make a lower output or a higher output which happens due to the size of the fins.
Example would be if your figured room comes up with 6000 btu's of heat loss it would take 10 ft. of baseboard with 180 deg. water running through it to heat that room. That would be 600 btu's x 10 ft of board. The higher the water temp., the more heat the baseboard puts out. The lower the temp, the less heat it puts out.
This is for typical #30 baseboard. They also make a lower output or a higher output which happens due to the size of the fins.
#12
Member
While it varies with each system layout, good practice is to vent at the high point of each zone. An auto vent on each zone automates the venting. https://www.supplyhouse.com/Watts-05...Vent-3679000-p
#13
Join Date: Jan 2005
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Air will tend to work it's way into an upstairs zone sooner than the downstairs. If there are vents on the upstairs baseboards that's where I'd start. The saddle valve would be a last resort for me. If you don't have any place to vent upstairs, I'd try purging at the valve near the circulator.
#14
I can't find a bleeder anywhere in the whole house.
I may need a refresher in bleeding the system. I am pretty sure it's just the upstairs zone.
I really can't remember how I did it after replacing the circulator.
I may need a refresher in bleeding the system. I am pretty sure it's just the upstairs zone.
I really can't remember how I did it after replacing the circulator.
#15
Member
I also want to remind folks... Temps Outside/Inside and Pipeline may be varied! It could also be caused by the contraction and expansion of metal! (We forget about this sometimes!)
mmcc100
voted this post useful.
#16
So, If I am going to bleed that zone, do i:
Shut the system off. Let it cool down.
Connect a hose to the drain just above the upstairs circulator. Open that valve.
Flip the lever on the pressure reducing valve.
Let the water run, until I see no air.
Close the valve. Flip the lever back.
Turn the system back on.
Am I missing anything?
Shut the system off. Let it cool down.
Connect a hose to the drain just above the upstairs circulator. Open that valve.
Flip the lever on the pressure reducing valve.
Let the water run, until I see no air.
Close the valve. Flip the lever back.
Turn the system back on.
Am I missing anything?
#17
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You would want to close the ball valves on both loops, connect your hose to the top hose bib, and procede as you stated. Keep an eye on the pressure & try to maintain between 15 & 25 psi while purging. Once you don't get any more bubbles, flip the reducing valve lever down & set your pressure to about 12 psi.
#19
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The ball valves are the ones with the flat handles (yellow on one zone, red on the other). Yes, leave them closed while purging. By doing so, you force the water in the normal direction of flow. If the ball valves are open, water could flow thru the boiler & circulator thus not purging the loop.
#20
Join Date: Jan 2005
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Since I can't seem to be able to edit the previous reply..... It's best, if you can, to purge into buckets keeping the hose end submerged. By doing so, you can actually see air bubbles coming out of the system.
#22
Join Date: Jan 2005
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After purging & opening the ball valves, look at the pressure gauge. If it shows over 12-15 psi, you will have to drain some water. The pressure reducing valve (fill valve) should stop feeding water at 12 psi. If it doesn't I can tell you how to adjust it.
#26
Member
Is anybody still here? I have some banging and I think it is expansion/contraction. Might be my imagination but it seems alot worse this year. Last fall I replaced a B&G series 100 with a Taco 007. I thought the B&G was too noisy and the Taco is no maintenance. I have a single zone no flow valve. Could the check in the Taco be causing the banging. I've kept it pretty well bled.
Thanks for any help.
Thanks for any help.
#28
Member
Seems like different radiator each time. It happens at night too, when the thermostat has it off (setback).
This is mmcc100. I forgot my new password an d am using my old account.
This is mmcc100. I forgot my new password an d am using my old account.
#30
Member
Upright cast. It’s an older house , @1940 that we need to sell. I think it’s expansion but it seems worse this year.
#31
Member
mac,
With a 1940's cast iron rad system I'm guessing it was originally a gravity fed system meaning there was no pump until added later. With CI rads I'm thinking you either have a monoflo system or a 2 pipe system which cannot be properly bled by conventional means like a loop system.
I'm guessing you have vents on each rad which is how your system must be bled. With a 2 pipe you may have some success but your mostly bleeding the main line and not so much of the rads.
On a 2 pipe all the rads are fed by a supply line and return in another line back to the boiler so bleeding from a purge station doesn't guaranty you will get all the air out of all the rads. On a monoflo system the rads are all fed and return to the same single line by special tees that force the water into the rads. This system cannot be bled by purging.
Pics of your system would be very helpful to see what you have.
With a 1940's cast iron rad system I'm guessing it was originally a gravity fed system meaning there was no pump until added later. With CI rads I'm thinking you either have a monoflo system or a 2 pipe system which cannot be properly bled by conventional means like a loop system.
I'm guessing you have vents on each rad which is how your system must be bled. With a 2 pipe you may have some success but your mostly bleeding the main line and not so much of the rads.
On a 2 pipe all the rads are fed by a supply line and return in another line back to the boiler so bleeding from a purge station doesn't guaranty you will get all the air out of all the rads. On a monoflo system the rads are all fed and return to the same single line by special tees that force the water into the rads. This system cannot be bled by purging.
Pics of your system would be very helpful to see what you have.
#32
Member
I’m not sure how to load pictures yet. It’s a 2 pipe system. When l replaced the circ l had to drain the system. I also had to drain it last winter to replace the aquastat. The thermostat shuts down at 11 and it was still banging at 1. Sometimes in the wall sometimes at the radiator. Not always the same radiator. It seems like expansion/contraction but l’m wondering if the check in the Taco circ is causing the problem. It’s the only new part to the system since last year.
#33
Member
mac,
You mention in an earlier post you have a single zone but in a previous posted pic it shows 2 pumps. You also mention no flocheck valve. What is keeping the water flowing in the right zone and only that zone on a call for heat.
You mention in an earlier post you have a single zone but in a previous posted pic it shows 2 pumps. You also mention no flocheck valve. What is keeping the water flowing in the right zone and only that zone on a call for heat.
#34
Member
Those aren’t my pictures. I also have a banging problem. I’m still trying to figure out how to post pictures.
There wasn’t a check in the system until this year. I’m wondeging if that could cause the banging.
There wasn’t a check in the system until this year. I’m wondeging if that could cause the banging.
#37
Member
The check is built into the circ. I didn’t put any thought into it until now. The B&G didn’t have one. It’s the only difference in the system since last year. I’m going to get rid of the check and see if that fixes it. I hope that fixes the late night banging too.