Intermittent boiler banging, knocking noises

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  #41  
Old 03-17-15, 10:21 PM
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banging and knocking

Hi, attached a few pics. Seems pump is installed ok per pic. Arrow shows the flow going downwhich looks right. Attached a pic of the pump brand and model and another pic of the circuitry. Pump is wired to p1 and p1c.
Bottom wire hookup to L1 & L2 in pic is for relay. Sent another pic of pump model and brand as first one was upside down.
Would a poor connection cause the pump to operate intermittently?
Thanks,
 
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  #42  
Old 03-17-15, 10:25 PM
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banging and clanging

Attached a close up of the circuit board hookup, may see a bit better.
 
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  #43  
Old 03-17-15, 11:03 PM
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We need to see the wiring harness on the right side of the zone control board.

2008 Wiring diagram: Page 25 MG-SG_Installation_&_Service_Manual [pdf] Wayback Machine.
 
  #44  
Old 03-18-15, 07:59 AM
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Trooper, HW,
Post 22. it starts with "PERSISTENT BANGING".
I see the pics you're talking about in post 23 and now post 42. That is not what I'm talking about.
I'm now on my desktop and things haven't changed.
No smartphone. tablet. but the pics are the same.
Just going by what Rich said in the post.
 
  #45  
Old 03-18-15, 08:06 AM
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HW,
I found that sight also and it doesn't even show that relay in the schematic which is why I was wondering what it was for. I know where they want the pump but according to Rich it isn't there according to #22.
 
  #46  
Old 03-18-15, 09:56 AM
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banging noise

Attached more pics of the wiring to the control board. Left the boiler off the entire night again and did not turn it on this morning. Can't stand the banging noise. It sounds as if the thing is alive. Warming up here on the west coast but will eventually need to replenish the hot water tank.
I'm now thinking the flow is the problem all along as per Trooper. The water is not getting out of the boiler. The pump works 90% of the time but doesn't engage 10% of the time. I have had the relay changed but could it be as simple as a connection in the rats nest of wiring is loose? Does a control board operate intermittently or if it goes does it just die? I also noticed in the wiring schematics of the boiler that P2 and P2G are for another pump hook up. The schematics show P1 and P1c as pump 1 optional whereas P2 and P2g show "pump 2".
I could try hooking up the pump to P2 and P2g?
Thoughts?
 
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  #47  
Old 03-18-15, 09:57 AM
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What relay are you talking about? The ladder diagram in the manual shows the relay contacts on the 120VAC side of the transformer, and the coil for that relay is called the "Pump Relay Coil"

Does this help Spott?

 
  #48  
Old 03-18-15, 10:00 AM
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I could try hooking up the pump to P2 and P2C?
You could try that, but it's not likely to make any difference. If you reference the 'Ladder Diagram' to the right, you will see that both relays do the same thing.

It WILL help if there is some issue with the relay contacts itself, so give it a shot.

In fact, you don't even need to move the P1C wire, as it is the same electrical point as the P2C wire (see ladder diagram). You only need to move the BLACK wire on P1 down to P2.
 
  #49  
Old 03-18-15, 10:08 AM
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From a National Electric Code standpoint, this is just plain WRONG. Armored cable must never be terminated in that fashion. There must be a connector and an 'anti-short' bushing used, just like the one from the pump.



Also in this picture, tell us where the small cables on TH1 & TH2 , and ES1 & ES2 are coming from.
 

Last edited by NJT; 03-18-15 at 10:27 AM.
  #50  
Old 03-18-15, 10:10 AM
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banging

The relay that I replaced and referring to is wired to L1 and L2 of the control board. Not sure if that is correct term (relay) for that specific object.
I took a pic of it and posted it below.
 
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Old 03-18-15, 10:13 AM
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If you have valves on each side of pump , you could remove the four Allen head screws of the pump motor and remove the motor from the pump housing to inspect the pump impeller ,and even power up the pump to be sure it is turning. Pump impellers will come off the end of the shaft.
 
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Old 03-18-15, 10:14 AM
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banging

Hi Trooper,

post number 23 shows a picture of the item I have been calling a "relay" and that item is wired to L1 and L2 of the control board.
 
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Old 03-18-15, 10:27 AM
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banging

Hi Trooper,

Also in this picture, tell us where the small cables on TH1 & TH2 , and ES1 & ES2 are coming from.
The small cables connecting to Th1, Th2 Es1 and Es 2 are coming from the zone valves I believe. I am recalling from memory as am at work this morning. Have attached a pic of the wiring rats nest. If you can see the four brown wires coming from the red and yellow nest, two of those brown wires are wired to the th1 th2 es1 and es2. Would have to double check which wires come from where but you get an idea.
 
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  #54  
Old 03-18-15, 10:29 AM
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The pump works 90% of the time but doesn't engage 10% of the time.
OK, now this is something we can sink our teeth into.

Is the 10% of the time the pump doesn't work when you hear the banging?
 
  #55  
Old 03-18-15, 10:33 AM
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post number 23 shows a picture of the item I have been calling a "relay" and that item is wired to L1 and L2 of the control board.
In that post, there are two pictures.

The first, on top, shows a 24VAC control TRANSFORMER.

The second, shows a ZONE CONTROL RELAY PANEL.
 
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Old 03-18-15, 10:34 AM
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All this discussion would be unnecessary if a multimeter could be used to measure the voltage at P1C and P1 when the boiler is acting up and banging.

That would tell us a LOT!
 
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Old 03-18-15, 10:39 AM
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The small cables connecting to Th1, Th2 Es1 and Es 2 are coming from the zone valves I believe. ... Would have to double check which wires come from where but you get an idea.
I need to know EXACTLY where they are coming from.

The wires on TH1 and TH2 will have absolutely NO EFFECT on the boiler UNLESS JUMPER 2 is installed, and in the pictures it does not appear that it is installed.
 
  #58  
Old 03-18-15, 02:17 PM
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Wires in TH1 & ZV2; He's stealing power off the zone control transformer.
 
  #59  
Old 03-18-15, 02:26 PM
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Wires in TH1 & ZV2; He's stealing power off the zone control transformer.
Interesting...

Makes me wonder why there's another transformer then...



Possibly running some valves from the external transformer, and some from the internal transformer.
 
  #60  
Old 03-18-15, 10:46 PM
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banging

Hi Trooper,

ok, I have looked at the wires connecting to the control board

Es1 and Es2 are both connected to the red wires that run from the 7 zone valves.

ZV2 is connected to 3 yellow wires that run from the zone valves and TH1 is connected to three white wires that I assume to be hot.
I note your request mentioned Th1 and Th2 but the one wire is connected to Th1 and ZV2 and the other wire is connected to Es1 and Es2 as you noted.

I believe the pump doesn't fire when I hear the banging noise. The cycle is extremely short and the water doesn't appear to be moving.
 
  #61  
Old 03-19-15, 06:47 AM
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ZV2 is connected to 3 yellow wires that run from the zone valves and TH1 is connected to three white wires that I assume to be hot.
I note your request mentioned Th1 and Th2 but the one wire is connected to Th1 and ZV2 and the other wire is connected to Es1 and Es2 as you noted.
Yes, HeatWoim pointed out that when the picture was lightened it could be seen that the wires are in TH1 and ZV2, and that it means the installer used those connections to take power from the transformer on the relay panel.

So you have SEVEN zone valves, and THREE are being powered from the internal transformer, and the other FOUR are being powered by the other external transformer. That makes perfect sense.

ALL of the endswitch wires are going to ES1 and ES2, and again, that makes sense.

I believe the pump doesn't fire when I hear the banging noise. The cycle is extremely short and the water doesn't appear to be moving.
If your belief is a true fact, and the pump is not running 10% of the time, then you need to determine the reason for that.

In my opinion, monitoring the voltage at P1 and P1C is the best way.

Moving the pump wires to the other relay output may also solve the problem.
 
  #62  
Old 03-20-15, 07:25 AM
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boiler died!

Hi Trooper,
last night moved pump wires from P1 and P1c to P2 and P2c to see if there would be a difference. Turned power back on and boiler went through three cycles without pump engaging. Turned off power and moved pump wires back to original P1 and P1c. Turned power back on, zone valves called for heat, boiler fired and "kettling noise" began. Went through 4 cycles and pump never engaged.
It looks like whatever was intermittent is now permanent. The heat is not leaving the boiler as the pump is not pushing the water out. So now it's the pump, which was recently replaced, or the control board. It seems as if the control board is partially working as the zones call for heat, boiler fires, cycles and stops firing when heat level is reached. Whatever is controlling the pump to start is not.
Is there an easy way to determine if the pump is ok?
 
  #63  
Old 03-20-15, 08:22 AM
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Pump: White wire to P1C, Black to P1
With AC/DC Multimeter Observe voltage at P1,P1C:
If voltage good 110-118 VAC: Pump problem.
If voltage bad: Test relay
 
  #64  
Old 03-20-15, 08:40 AM
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If voltage good 110-118 VAC
Many areas much higher voltage these days, and it varies with location.

I would say 110-125 . At my home the average is 123 over long period.

But yes, you need to do some testing with a multimeter.
 

Last edited by NJT; 03-20-15 at 03:19 PM.
  #65  
Old 03-20-15, 03:02 PM
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Richard,
If you're comfortable with electricity remove the pump wires and hook up to an external source to see if it solves the problem.
Put the wires into an outlet to test or you can put a plug on the end and put it into an outlet.
Hook up your bypass again and have constant circulation until you get the board fixed.
 
  #66  
Old 03-22-15, 09:23 AM
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boiler is now working!

Well, the boiler is now working fine and no more banging noises. The control board has been replaced and all is working fine. The relay on the control board must have been bad.Thanks to all of the contributors for help on this.
Couldn't have done it without you.
cheers,
Richard
 
  #67  
Old 03-22-15, 11:51 AM
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A small light to indicate pump is being powered would have taken a lot of the mystery out of the problem.
 
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Old 03-22-15, 01:46 PM
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Or a multimeter.......................

Thanks Rich for letting us know it's all good now!
 
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