Boiler Bypass confusion- stumped!

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Old 01-01-11, 12:02 PM
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Boiler Bypass confusion- stumped!

Hi folks Ė

Been trying to understand the boiler bypass concept using some of the excellent information provided on this forum so I can verify that my installation is proper. Iíve been studying the installation instructions for my boiler which maybe was installed in the early 90ís. But I am stumped? Iím only asking the forum experts for help here after I did my homework and looked at past threads and referenced material concerning boiler bypass vs. system bypass. I was wondering if my manual is wrong. Itís probably me but I spent a lot of time and Iím just not getting it!

http://www.newyorkerboiler.com/pdf/8...R5%20(web).pdf

The above manual on page 10 bottom right, item A.3.d, talks about possibly installing a system bypass. The manual never talks about a boiler bypass. That bypass discussion in A.3.d references figures 5 and 6 on pages 12 and 13.

Questions:

(1) Seems to me in figures 5 and 6 the water flow arrows indicate a system bypass, but the bypass pipe is labeled boiler bypass?

(2) yet in figures 5 and 6 how do you get the flow indicated by the arrow across the bypass pipe if the circulators are on the system side? Shouldnít the flow arrow be in the opposite direction across the bypass pipe? In other words, should it be flowing from the return pipe over to the supply pipe and thus the depicted configuration would in fact actually be a boiler bypass?

It almost seems like whoever tried to handle the bypass section of the manual really didnít understand boiler vs. system bypass. Seems to me like you couldnít tell from the manual what they really want? But I guess if I had to bet on who doesnít understand Ė them or me Ė it would be me!

ĖAny help would be greatly appreciated!
 
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Old 01-01-11, 03:44 PM
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hi again folks -

Just thought I would post this since it's related to my question in the previous post. If I understand the info on another thread here today, this setup for the bypass looks wrong in that the return valve is all the way open and the bypass valve is almost all the way closed?

I think the installers were trying to set up a boiler bypass regardless of what the manual said that I referenced in the previous post.

 
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Old 01-01-11, 07:12 PM
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You will have a system bypass if the circulator is between the boiler and the bypass and a boiler bypass if the bypass is between the circ and boiler.
 
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Old 01-01-11, 07:34 PM
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You need to show more pics. I cant tell how your boiler is really piped. There may be other factors

NJ trooper will help you on this. The ball valve looks almost closed but really is more open then you think. These really are not good valves to use in by pass systems.

Your circs are on the return side. Water flows least resistance and will prefer to go through the bypass before going through the boiler.

Its a whole head pressure flow thing that might take along time to explain here if you dont understand it.

Newer boilers have a boiler circ plus zone circs.

Mike NJ
 
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Old 01-01-11, 07:43 PM
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It looks like a series of bad and/or incomplete edits in that manual.

Fig 5 & 6 DO show a BOILER bypass, but you are correct Dad! The flow arrow is definitely backward.

Your bypass is obviously not full sized. And on the return side at least, the valve in the boiler return is on the wrong side of the bypass to do any good adjusting the bypass flow. Is there a valve in the supply side pipe, between the bypass and the boiler?
 
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Old 01-01-11, 07:52 PM
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Water flows least resistance and will prefer to go through the bypass before going through the boiler.
Mike, it's true that water will take the least resistant path, but in this case, being that the bypass appears to only be 3/4" pipe, the least resistant path will be through the boiler.

Another reason for this is that once water is flowing in a pipe, it won't want to 'turn'... momentum will keep it going straight through the tee fitting. MOST of the water will be coming from the boiler, with a (comparative) trickle coming through the bypass pipe.

So, even if the bypass were full size, the boiler would STILL present the least resistant path.
 
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Old 01-01-11, 07:58 PM
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Yeah I am not sure thats a by-pass but I have been wrong on many a times. I would like more pics. I tried to look at the diagrams but got dizzy turning my head sideways.

After looking at the pic again yeah it will not turn. ( Hey wait thats a mono flo tee!!!) LOL

Mike NJ

Happy New year!!!
 
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Old 01-01-11, 08:05 PM
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HA HA ... a monoflo... that's funny!

Did you know that Acrobat allows you to rotate the pdf files? Yep, there's an app for that!

HNY to you also... hey, that wasn't you lighting them quarter sticks last night was it?
 
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Old 01-01-11, 08:12 PM
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No but we had some doozy's here. Felt like the 4th. Lets see if Zoesdad posts again. Hopefully with more pics.

Mike NJ
 
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Old 01-02-11, 08:29 AM
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Thanks guys for your time.

Originally Posted by drooplug View Post
You will have a system bypass if the circulator is between the boiler and the bypass and a boiler bypass if the bypass is between the circ and boiler.
Thanks droop! Iíll be posting more pics

Originally Posted by lawrosa View Post
You need to show more pics. I cant tell how your boiler is really piped. There may be other factors

NJ trooper will help you on this. The ball valve looks almost closed but really is more open then you think. These really are not good valves to use in by pass systemsÖ
Thanks Mike. Iím going to post more pics.

Originally Posted by NJ Trooper View Post
It looks like a series of bad and/or incomplete edits in that manual.

Fig 5 & 6 DO show a BOILER bypass, but you are correct Dad! The flow arrow is definitely backward.

Your bypass is obviously not full sized. And on the return side at least, the valve in the boiler return is on the wrong side of the bypass to do any good adjusting the bypass flow. Is there a valve in the supply side pipe, between the bypass and the boiler?

Thanks Trooper. Iím getting the camera out now and Iíll take more pics. I know this sounds like BS but it actually did occur to me this morning (no lie, maybe something to do with getting sleep?) that even if that is supposed to be a boiler bypass that return valve and other valve in the pic couldnít be right. I guess that bypass pipe should be on the other side of the return valve. I did think the 3/4 inch pipe was wrong since thatís smaller than the supply/return pipes. That was going to be my next question.

Now this whole thing is really mysterious? Iím going to get more pics now and post them so you guys can see the entire thing when you have the time?
 
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Old 01-02-11, 09:57 AM
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hi guys -

Got a few more pics then my battery got tired and went to sleep (charging it now in case you want another pic).

I put some dashed arrows in the pics to help identify the so-called bypass pipe or whatever the heck it is ?









 
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Old 01-02-11, 11:07 AM
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Looks like a boiler bypass. like Trooper said the valve on the return is useless when it come to adjusting the flow between the boiler and the bypass. Did you measure the temperature of the return and supply water to find out the Delta T? and the temperature after the bypass?
The bypass on my boiler is not full size but it is mixing the supply water with the return water, my delta is 30 degrees.

Unless the idea is to slow the flow for the whole system including the boiler, allowing the boiler to heat the water faster if needed, but then it will not deliver even/enough hot water to the whole system.
 
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Old 01-02-11, 11:36 AM
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This may help you understand bypass piping.

Bypass_Piping_Explaination
Scroll down to the bypass info on the link.

You have a bad attempt at a boiler bypass. The bypass should be full sized and if there is a valve in the bypass it would be full open. There would have to be a valve either supply or return but between the tee's for the bypass and the boiler.
 
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Old 01-02-11, 01:12 PM
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I'm thinking that your system doesn't even need a bypass anyway. What were your emitters again? fin-tube?

Also thinkin' that if you just went ahead and left the bypass valve fully open, you might not even notice anything different. Any flow that did occur in the bypass would offer a bit of protection.
 
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Old 01-02-11, 03:39 PM
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Originally Posted by esalman View Post
Ö Did you measure the temperature of the return and supply water to find out the Delta T? and the temperature after the bypass?....
thanks for your time esalman. That is one of the questions I had for you guys here. How do you measure the temperature? Is there some kind of instrument you put on the pipe? Googled and I canít find anything?

Originally Posted by rbeck View Post
This may help you understand bypass piping.

Bypass_Piping_Explaination
Scroll down to the bypass info on the link.
You have a bad attempt at a boiler bypass. The bypass should be full sized and if there is a valve in the bypass it would be full open. There would have to be a valve either supply or return but between the tee's for the bypass and the boiler.
thanks rbeck. Did read that explanation the other day. Thatís what I was thinking Ė some kind of bad attempt at bypass? Would love to know what the installers thought process was at the time? Those kinds of mysteries bug me! You never get to understand what they were thinking. Maybe 3/4 copper pipe left on the truck?and maybe back then bypass wasnít understood like it is today ?(Iím grasping)

Saw your post the other day talking about the bypass valve where you said it should be fully open. Thatís what got me thinking about this whole thing. Of course I understand what you are saying, if the valves are properly placed you should open the bypass fully and then use the return valve to adjust the flow through the bypass and return paths. At least I hope I understand that? As Trooper pointed out my return and bypass valves are in the wrong spots anyway.

Originally Posted by NJ Trooper View Post
I'm thinking that your system doesn't even need a bypass anyway. What were your emitters again? fin-tube?

Also thinkin' that if you just went ahead and left the bypass valve fully open, you might not even notice anything different. Any flow that did occur in the bypass would offer a bit of protection.
Trooper thanks a lot for your time and expertise. I have these little flat thingies against the wall called Base-Ray. They are about 2 inches deep, 7 inches high and have these horizontal oval open slots near the top about 9Ēwide x 1Ēhigh, spaced a few inches apart. Guess these are just called radiators?

Think I would like to just leave the bypass fully open to get a bit of protection as you say. What you are saying sure seems to make a lot of sense- system really doesnít need a bypass. Seems like it really doesnít have much of one now and I guess itís been operating for years that way. Didnít really want to start fooling around and wasting peoples time here, but I was thinking if something is really set up very bad, I should try to do something about it!

Thanks for your time and good information once more.

(p.s. Lawrosa also pointed this out - why in the world would someone use a ball valve for flow control? All you have to do is bump it with your rear-end and you changed things? But maybe that's an indication they meant to have it fully open? I'm wandering here. I'll shut up!))
 

Last edited by zoesdad; 01-02-11 at 04:14 PM. Reason: left out word 'valve'
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Old 01-02-11, 04:15 PM
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Guess these are just called radiators?
BaseRay is CAST IRON baseboard... made by Burnham ... nice stuff.

One thing you can always do with a ball valve is take the handle off and hang it on a nail near the boiler. Prevents OOPSIES...
 
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Old 01-02-11, 04:21 PM
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MP748 - Mr. PEX MP748 - Strap-On Pipe Thermometer for 1/2"-4" Pipe (70-200F)

More accurate if you insulate the pipe either side of the instrument.

You can also use those 'point and shoot' Infra-Red jobbies, but you do need to understand the term 'emissivity' in order to get reasonably accurate readings. Paint the spot you want to measure with flat black paint and you should be close enough. The insulation trick is a good idea also... it will give you a better idea of the temp of the WATER, rather than the surface of the pipe.
 
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Old 01-03-11, 08:56 AM
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Originally Posted by NJ Trooper View Post
BaseRay is CAST IRON baseboard... made by Burnham ... nice stuff....
Gotcha Trooper. Now at least I can use the right terminology.

Originally Posted by NJ Trooper View Post
Ö
One thing you can always do with a ball valve is take the handle off and hang it on a nail near the boiler. Prevents OOPSIES...
Excellent idea. Thatís not hard to do.


Originally Posted by NJ Trooper View Post
MP748 - Mr. PEX MP748 - Strap-On Pipe Thermometer for 1/2"-4" Pipe (70-200F)

More accurate if you insulate the pipe either side of the instrument.

You can also use those 'point and shoot' Infra-Red jobbies, but you do need to understand the term 'emissivity' in order to get reasonably accurate readings. Paint the spot you want to measure with flat black paint and you should be close enough. The insulation trick is a good idea also... it will give you a better idea of the temp of the WATER, rather than the surface of the pipe.
Thanks. Was getting nowhere with google. Iím going to get the instrument. Good tips for how to do it. Looks like itís good to have for that price. Iíll do some homework to learn about 'emissivity'.

Thanks again Trooper for your time and the excellent information and help.
 
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