# Just wrapping up a knight boiler



## 907plumber (Mar 13, 2010)

Thought I would throw up a couple of pics. This is a lochnivar knight with squire sidearm. This is for one of my part time gigs. The company owner Is real pleased with it and gonna take a picture for his website. The knight rep is coming put to take a look so I'll get some feedback. Really just wanted to try the forum app on my phone. Pretty cool!


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## Mark Potter (Sep 29, 2011)

Looks good is this a residential building? You ran the exhaust pipes through top of building? Good post!

Sent from my iPhone using PlumbingZone


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## Mississippiplum (Sep 30, 2011)

looks good but i would have layed down a sheet of plywood to make that build-up look a little nicer and tideyed up the wiring a little but besides that you did a good job :thumbup:


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## Titan Plumbing (Oct 8, 2009)

Mississippiplum said:


> looks good but i would have layed down a sheet of plywood to make that build-up look a little nicer and tideyed up the wiring a little but besides that you did a good job :thumbup:


Would you have used a sledgehammer to demo the platform first?


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## Mississippiplum (Sep 30, 2011)

Titan Plumbing said:


> Would you have used a sledgehammer to demo the platform first?


:laughing: yeaaaa then i would have found some lawn chairs to set the plywood on, makes the janitores job easier, he can clean underneath it.




on a more serious note, looks like you read the plumbing tips section recently.


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## Titan Plumbing (Oct 8, 2009)

I'm just a lurker...heck, I'm not even a plumber...:laughing:


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## Plumberman (Jul 7, 2008)

Titan Plumbing said:


> Would you have used a sledgehammer to demo the platform first?





Titan Plumbing said:


> I'm just a lurker...heck, I'm not even a plumber...:laughing:


Bam, Bam!


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## Mississippiplum (Sep 30, 2011)

Titan Plumbing said:


> I'm just a lurker...heck, I'm not even a plumber...:laughing:


 
:thumbup: trying to find a solution to yur leaky diy washingmachine job?

lol just kidding


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## DesertOkie (Jul 15, 2011)

Where's the plumbers putty?


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## Mississippiplum (Sep 30, 2011)

or the famous "schwinn'' coupling :laughing:


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## Titan Plumbing (Oct 8, 2009)

Mississippiplum said:


> :thumbup: trying to find a solution to yur leaky diy washingmachine job?
> 
> lol just kidding


Nah, been having trouble going to the bathroom and when I Googled a solution...this was the first site that came up...


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## Mississippiplum (Sep 30, 2011)

Titan Plumbing said:


> Nah, been having trouble going to the bathroom and when I Googled a solution...this was the first site that came up...


:laughing: thats funny


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## 907plumber (Mar 13, 2010)

Mississippiplum said:


> looks good but i would have layed down a sheet of plywood to make that build-up look a little nicer and tideyed up the wiring a little but besides that you did a good job :thumbup:


We got it all tidy. The pic was taken before the wiring was even started. That romex was the only wiring started. I wanted to lay down some wood but the guy who made the bid decided against it.

And yeah if it's a straight shot we run the exhaust and intake in the old flue pipe


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## Mack508 (Oct 16, 2011)

I just did a knight boiler for the first time with the squire. I am used to doing the Buderus GB's. But here is a picture of the one i did.


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## 907plumber (Mar 13, 2010)

Its amazing how much pipe and space these things use. I cant really tell in your pictures, did you do a primary/secondary loop? Also whats the deal with that huge pump? How come it needed to be that big.


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## Mack508 (Oct 16, 2011)

Yes there is a primary/secondary loop, its the grunfos 99 pump just to the bottom left of the boiler. The reason for the big B and G pump is because this house is 4500sq ft house built in the late 1800's and has all cast iron radiators, close to 30 of them. So they wanted a big pump to push all the water. better to be a little over sized, then being undersized and going back.


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## ILPlumber (Jun 17, 2008)

Where's the expansion tank? Maybe my eyes are failing me....


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## Mack508 (Oct 16, 2011)

Its on the right side. i couldnt get it in the picture, i was using the camera on my phone.


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## ILPlumber (Jun 17, 2008)

Oh OK. I don't see a pipe going that direction. Doesn't matter just curious.....


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## 907plumber (Mar 13, 2010)

Mack did you just use a ball valve in the loop instead of a differntial pressure bypass valve? I just used a ball valve. Also did you use a system supply sensor? I didnt use that either.

Whats everyones opinions on ball valve vs differential pressure bypass valve? Im pretty green with this boiler stuff. I can pipe one up just like a diagram says to, but am at a little bit of a loss when it comes to choosing the right parts. 

The guy I plumbed that knight boiler for doesnt have much of a clue either or Id ask him. He is a sheetmetal guy who just leases his plumbing card. He was the one that told me to use the ball valve and omit the sensor. But I have had other supervisors throw in a ball valve too. And it seems standard operating procedure is to just leave that ball valve half open and call it good


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## Mack508 (Oct 16, 2011)

I just use a ball valve for the bypass. here is a picture of another one i did this week. a little different set up.


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## 907plumber (Mar 13, 2010)

then what are you doing with the bypass? Supposedly we are just to leave it closed. If that is the case then what is the point of it? I wasnt present when the Knight rep came out and looked at my boiler so I couldnt ask him that question. Of course the guy bidding these jobs didnt ask any questions either :huh: so everytime I ask him a question he doesnt know, probably doesnt care. He just wanted the rep to look at it to see if it was plumbed right. It would have been nice to know the whys and hows


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## Nikolai (Dec 17, 2009)

I would have used Honeywell ZV's instead of Tacos but the install looks good. 

Lockinvar makes a nice product but I hate their boiler/WH design, it makes for such a cluster fawk of piping, especially the Squires where the cold inlet is down low. The WM Ultra/Bradford White combos I've installed came out much cleaner.


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## Scott K (Oct 12, 2008)

Having the Cold inlet low is a more proven, reliable, & durable place to introduce cold water into the tank than through a dip tube at the top of the tank. 


You NEED a differential bypass valve, at a minimum, to bypass some of the flow of the pump when only only some, or one, of the zones are open. If you don't have a pressure differential bypass, when one zone valve opens, the pump tries to ram all it's flow through one zone. If you have multiple zone systems with no differential bypass valve, what can happen is say you have 5 total zones, and only 2 zones are open. 1 of those zones will become satisfied meaning one of the zone valves will close while 1 remains open. When it closes it will take excess wear and tear on the ball as it tries to come down to stop the flow where the pump can now only route some of it's flow through one zone. This can cause premature wear and tear on your zone valves, as well as unneccessary erosion on piping, valves, fittings,etc. 

Even worse - you CAN cause short cycling on your boiler which puts wear and tear on equipment- as your pump is ramming all it's flow through one zone, it is pushing more water than the loops in the radiant heat emitter can give off heat as the boiler ramps up quickly to satisfy what it thinks is a large demand. You then see warm water start to return to the boiler inlet which will cause it to modulate down and short cycle as it no longer needs to produce heat. Overtime, wasting fuel and reducing system efficiency. 

With the advent of delta P pumps with ECM motors like the Grundfos Alpha & Wilo Stratos, Differential pressure bypass valves are become a thing of the past. These pumps react to the zone valves opening and closing and throttle the flow accordingly only trying to maintain a set differential pressure. Basically what this means is say you had 5 zones and each zone required 1 GPM. The pump would ramp it's flow up or down by 1 gpm as each zone opened and closed (roughly - it's not exact, but damn are these pumps good at getting it close as far as the flow you need and balancing, etc.). Even better - these pumps use 50-80% less electricity than your typical wet rotor circulator (e.g. Grundfos 15-58, etc.), AND, the cost of them compared to a wet rotor circulator, a differential bypass, and some fittings & labour to install is roughly the same, yet the ECM circulator as I just mentioned uses way less power, AND, is way easier to set up/tune to your system which saves time, and labour on top of aesthetics, AND, it has a display which shows you how much power it's using at the time, as well as how many GPM"s it's flowing. 

Taco apparently has some new zone valves out that use hardly any power compared to the tried, tested, and true honeywells that seemed to be the go to zone valve on the market up until recently.


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## Nikolai (Dec 17, 2009)

Good write up. Just spent some time looking at the Alpha pumps on Grundfos' website, they look nice and sound even better! Might have to convince my company to try them out.


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## Scott K (Oct 12, 2008)

*No Convincing needed*

If you're planning on installing a fixed speed pump, with zone valves, and a bypass, as I mentioned above(to serve various radiant heating zones), the Alpha installed is the same cost as the fixed speed pump and the differential bypass installed parts/labour. IN fact as I mentioned above,not only is about the same cost as the fixed speed circ and diff bypass, but it also saves your customer money on electricity (50-80%), and it saves you time setting up your system as you don't have to tune the diff bypass. It's really a no brainer. And even better - you COULD also potentially upsell you customer on using Alpha's for the other pumps such as the boiler pump, or indirect bump or other fixed speed applications due to it's power savings.


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## gtmechanic (Feb 15, 2009)

One thing stands out, your potable water expansion tank is upside down. You get air accumulated under diaphragm and with time it drys out. There is a reason for lettering on the tank be readable without standing on the head.


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## Redwood (Sep 8, 2008)

gtmechanic said:


> One thing stands out, your potable water expansion tank is upside down. You get air accumulated under diaphragm and with time it drys out. There is a reason for lettering on the tank be readable without standing on the head.


Of course that would be subject to the installation instructions of the manufacturer... Right?


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## Scott K (Oct 12, 2008)

As I understand it, most expansion tank instructions I've read suggest that hanging the expansion tank so no air can accumulate it is the best orientation (e.g. the threaded connection on the top) but an option orientation as per instructions is upside down. However, as was pointed out, I personally will ALWAYS install them so they hang from the piping for the very reason GT pointed out.


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## Redwood (Sep 8, 2008)

Instructions do vary...
Watts says any way
Flexcon says up or, down...


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## Mississippiplum (Sep 30, 2011)

If the exp tank is hung horizontally then it needs to be supported, from above or below. It only takes a water logged exp tank and a little movement to cause problems.


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