Noisy pipes near boiler when only 1 zone is open

Blackforestnoob

Hello, 2 years ago I had a triangle tube solo 175 boiler installed and it uses a grundfos 3 speed circulator pump (ups26-99fc). It replaced an old leaky boiler from the 60,s. The existing piping was used, there are 4 zones using white Rodgers zone valves. System has worked very well until this heating season. When the boiler is running with only one zone open it makes a loud "crackling" sound which seems to be the loudest about 3 feet after the pump before the zone valves. If two or more zones are open the sound is non-existant. What things should I check? Could it be the pump? I am thinking something else since it is quiet when more zones are open. I don't think the system has any inhibitor in it, would this help quiet it down when only one zone runs? Thanks in advance for any advice!

Zman

Pictures?

A picture of the boiler room piping would help.

What type of heat zones do you have?

What does the pressure gauge on the boiler read?

Where is the expansion tank in relation to the Grundfos.

It sounds like you are describing pump cavitation.

Carl

Blackforestnoob

Pictures

Thanks for the reply.

The system is all baseboard heating, the different zones are 1. bedrooms, 2. living room, 3. basement, and 4. sunroom. 

The pressure gauge is right at 13, it is pretty steady at that pressure. 

The expansion tank is located on the pipe after the water has ciruclated through the zones. 

Secondary question, what temperature should the boiler be set at? Would having it too high cause the problem?  It is set at 180 by default. 

Everything heats well it just makes that noise when only one zone is open, rather than waiting for complete failure I am hoping to figure it out since the cold weather is setting in here in Colorado.



I'll take some pictures and post them up after work today

kcopp

im thinking.....

its not piped primary secondary and there is a flow issue.

Blackforestnoob

Pics

Here are the pics.

kcopp

I was right....

its not piped right.

Unknown

incorrected pipings

From the start, the system is piped incorrectly... for one, having one oversized pump for the WHOLE system won't work... secondly, when only one zone is calling, the oversized pump is screaming pushing water thru ... when all zones are calling.. the pump is still slightly oversized. Time to get a real hydronic heating pro and hopefully you get your money back from the 1st unquaflied installer.

Blackforestnoob

How to fix

Thanks for the feedback everyone.  I bid the job out to 3 companies when I bought the house and this is essentially the way all 3 had explained they would fit the new boiler.  Beyond the pump being oversized what else is missing or needs to be fixed, I would like to be able to point out what needs to be changed/added/deleted so I can get the work done and not have to worry about it anymore. 

Based on the responses I decided to look at the manual online.  Since the primary/secondary was mentioned I found this information in there:

In new or retrofit applications in which primary/secondary arrangement is not utilized, the PRESTIGE Solo allows this flexibility due to a lower boiler pressure drop. 

However, it states that if you utlize the setup that way with multiple zone valves you will need to install a by-pass loop with a pressure differential valve. There is not a bypass loop.   Would adding a by-pass loop and having a correctly sized circulator correct the piping or is the installation way off?

Thanks Again for the help, the next two days are supposed to drop down to 12 degrees, luckily the system still heats, it's just noisy right now, but I would guess there is damage being done and will want to get things fixed sooner than later. 

kcopp

figure 10....

on page 27...

http://www.triangletube.com/documents/1/Prestige%2060%20175%20250%20399%20TriMax%20Manual%20030713.pdf

Blackforestnoob

How about figure 11 on the next page

That is pretty similar to how it is actually set up now minus the bypass. 

I've attached that schematic.

If not I'll find someone who can set it up as shown in figure 10.

kcopp

from the pix....

you put up there is no primary/ boiler circulator on your set up. You should have One for the zones and One for the boiler.

Zman

Piping

I really love the "boiler is piped wrong" or "call a real pro" responses.

Why bother to post?





The fact of the matter is, Triangle Tube allows non primary/secondary installations. It is in their manual and there training classes.As long as you meet the flow requirements,it is not the problem.



Does the noise occur when any of the zones are the only one operating or is it one particular zone that causes the problem?



Your circulator is probably too big. Is it set to "speed1"?



On the boiler press the  "mode" button until it says "info"

Now press "step" 2 times. Record the numbers as you press step it will say "1 xxx" then "2 xxx" These are the supply and return temps. If the differences between these numbers should be between 5 and 20 depending on the size of the zones.



I cannot tell much from the pictures. Is the circulator and the zone valves on the supply with the circulator arrow pointing to the right? Is the expansion tank on the return?



Carl

Tom_133

This fix is pretty simple

If I am seeing this right I would probably install the two closely spaced tees, use the existing pump for primary loop on speed 1 and install a grundfos alpha on the secondary to eliminate the noise from velocity. Of course I may not be seeing this quite right either. Who installs a new boiler but no new zone valves and air separator?

Blackforestnoob

Piping

Does the noise occur when any of the zones are the only one operating or is it one particular zone that causes the problem?

It will occur on any of the zones when that particular zone is the only one open.



Your circulator is probably too big. Is it set to "speed1"?

It has been set at speed 2, I have turned it down to "1" but that does not eliminate the problem.



On the boiler press the  "mode" button until it says "info"

Now press "step" 2 times. Record the numbers as you press step it will say "1 xxx" then "2 xxx" These are the supply and return temps. If the differences between these numbers should be between 5 and 20 depending on the size of the zones.

Unfortunately the supply and return are generally close to the same temperature up to 5 degree difference. 



I cannot tell much from the pictures. Is the circulator and the zone valves on the supply with the circulator arrow pointing to the right?

It is somewhat hard to tell from the pics, I'll see if I can take some better ones.  The circulator is taking water away from the boiler and pushing it towards the zone valves, so yes, it goes to the right.

 Is the expansion tank on the return?

Yes

I mentioned in another reply that there is not a differential bypass valve and loop on the system, would that take care of the problem? 

Here is how it is piped minus that bypass loop.

Zman

Over pumped

I think you are clearly over pumped. A 15-58 or 15-55 alpha would be plenty for most baseboard systems. The other issue is that you will wear out your pipes with that kind of velocity.

The question is, why did the noise just start?

Is the air vent on the top of the boiler open (the little thumb cap)?

I would switch the pump before I repiped it.

Carl

Blackforestnoob

Pump

Thanks, I'm pretty sure I can take on the task of switching out the pump, I'll give that a try and then report back if that eliminated the noise.  That'll give me the opportunity to install some isolation flange valves while the pump is out. 

Not sure why the noise just started, it is possible it was happening before but was quiet enough that it wasn't noticed and has become louder now.  

The air vent is open on top of the boiler.  Each zone has a manual air vent at the high points as well.