A question about Circulators on Packaged Boilers

JaredM_3

Ok, good point

on the low water cut off...they would find the cheapest out there. I have had similar experience with the cheap relief valves. But how about providing a tapping expressly meant for that purpose? Keep it under the hood on the gas boilers, like behind the door on a Burnham series 2 (the model I am most familair with, other makes have similar designs). The oil boilers would have to be outside the jacket but provide the tapping in the casting in a factory authorized location. It's just a pain...the probe type cutoffs sometimes don't fit into a 1-1/4" x 3/4" black tee which means using a 1-1/4" tee and a bushing, that usually allows it to fit. But it's just more fittings for us to stock and remember to take on a boiler install.

We recently bought the ProPress tool and I was just checking if they made an 1-1/4" x 3/4" FPT tee for LWCO installs...alas they do not. They only make it in a 1/2" FPT version in the price sheet I have, which is dated 2003.

-Jared

Unknown

LWCO on Packaged HW Boiler

The three primary reasons that LWCO's are not with the boiler are that they need to be in the supply pipe above the boiler, there are simply too many personal choices out there regarding brand, voltage and type and that approximately only 7 states are even enforcing the use of them. When the code is adopted uniformly then some consideration may be given to this. In most cases though, it will require design and production changes to the boiler and very lengthy recertification processes due to the design and control changes.

The stringent requirements that equipment manufacturers have to follow are difficult for many folks to understand. It is not as simple as just making a change in the equipment design and configuration every time a good suggestion is made. It is a lengthy and very expensive process to recertify. Hope this helps.

Glenn Stanton

Burnham Hydronics

Unknown

We have several

large oil accounts that brought up the configuration change. The concern is not at the installation level, but rather at the sales and management level of these companies. Many of the Petro companies use our knocked-down or semi-packaged boilers where the pump is not mounted.

Glenn

DanHolohan

I know that a change in any boiler

isn't a simple task. A couple of questions, though. The 2000 International Mechanical Code calls for low water cutoffs on all boilers, both steam and hot-water, regardless of size. Doesn't this apply across the board?

And why does the hot water low-water cutoff have to be in the piping and not in the boiler when it's in the steam boilers? Is this written into some code?

Thanks for your insights, Glenn. Much appreciated.

DanHolohan

Interesting

how the sales guys get to override the installation guys, especially considering how the pump on the return will probably have the installation guys spending more time trying to bleed the air from the radiators on start-up.

Gil Carlson had this great expression, "What you save on the meat you spend on the mashed potatoes."

Unknown

The steam boilers

require the LWCO to monitor the lowest permissable water level in an effort to keep the boiler from dry-firing. In the case of a Hot Water boiler the LWCO is serving two purposes. First to shut the boiler down in the event of a possible system break or failure, provided the PRV hasn't already kicked in and flooded the basement. This is more than likely the reason why some of the PRV makers state to shut off the PRV after static fill is reached.

Second, in the event of an improperly wired zone of heat or Indirect Heater the possibility of a dangerous overheating condition exists whereby the high limit may be out of the circuit. In this event, both pressure and temperature will escalate until the relief valve blows off. At this point the super heated boiler water can flash to steam and make the situation even more dramatic. This steam will more than likely occupy the upper tier of the boiler vessel and the connected supply pipe. This is where the LWCO needs to be installed in an effort to sense this condition. As stated in an earlier post, most packaged residential boilers do not have a dedicated tapping in the top tier of the boiler for this purpose.

Enforcement of the 2000 International Code is not uniform throughout the states in regards to this. New Jersey and the NYC and Long Island areas were the latest to adopt thislast year. I conducted almost 3 weeks of training sessions last year throughout NJ on just this topic at the request of some of the distributors and utilities.

Rhode Island was the first state to require LWCO's on ALL hot water boilers way back in the 1980's long before the 1998 International Code adopted it. If I remember correctly, the older BOCA Code required a LWCO on a hot water boiler if it had radiation at or below the water level of the boiler. I could be wrong but I also believe that it referenced installing it in the supply pipe as close as possible to the boiler with no walve or branch tee in between. Hope this helps.

Glenn

DanHolohan

I've got a copy

of the 2000 code on my desk and it just says ALL boiler. It doesn't specify where, though. Enforcement may not be uniform, and I can understand that due to manpower restraints, but doesn't it apply nevertheless?

Unknown

In many seminars

that I do I have both installation techs and service techs from big companies in the same room sitting across from one another. I'll bring up the topic of service valves before and after pumps and PRV's for more servicability. The installation guys always tell me they would like to put them in but for budget reasons, they can't afford to.

The service guys across the table always answer with references to the 2 or 3 hours that were spent on the jobs in the middle of the night because something leaked or failed during the warranty period with no service valves. But neither of them were really at fault as they were doing what they were required to do.

I had the opportunity to spend a few days with the managers and sales people of one of our biggest oil and gas accounts earlier this year and trained them on Boiler Installation Issues. Some of the issues I always address in these are Combustion Air, Chimney Issues and Near Boiler Piping for better servicablity. Really raised some eyebrows when I discussed the extra time on the jobs because there were no valves. They are now including them in the quotes along with pump isolation flanges.

Glenn

Weezbo

Secondary High limit and LWCO...

n'est pas? in the late 70's and early 80's we Had a boiler inspector who liked them personally:)

Rudy

pumping away

I have done great things with pump away. One job had a burned out circ. on the return. This was a B------- Boiler that was installed in the late 1990s and to my surprise it wasen't leaking. This house has town water, that is full of air and hard to bleed. I talked to the cust. and she said the house was not realy balanced(one side cold, one side hot). I Told her I would fix it and installed a spyrovent-pump away setup. She is very happy with the heat now. It balanced the whole house and using a circ with a chek valve I was able to remove the leaking chek. The air in the lines is pushed or pulled to the return so why have a water cooled circ. in a place where the air can burn it out? When I left it still had some air in it but I went back to clean it just the other day and no air was found. Thanks to dan.

Unknown

Glenn, the requirement for

LWCO's in Rhode Island was determined first of all by the gas company setting it as a requirement for gas forced hot water boilers. I was the training supervisor and also responsible for the testing lab at the time and had run several tests on boilers and proved that under numerous cicumstances an unsafe low water or no water condition could occur. It was on my recommendation that we set the precedent of requiring LWCO's it was not long after that the state dept of regulation instituted it state wide.

Unknown

Glenn a question about air for combustion -

are you using confined space/unconfined as a criteria for air for combustion?

Unknown

Glenn to install a low water cut off

in the boiler would it not just require another tap being drilled into the boiler and placing the low water cutoff into that tap with a proper well.

I understand the cost for retesting but perhaps as other changes that are being made to boilers come about it could be included at that time. I would much rather see the low water cut off in the boiler as part of the package.

Unknown

More to it

than just drilling and tapping Tim. The molds and castings would all have to be changed to incorporate a reinforced boss to drill and tap through as well as changes to the jacket panels and wiring harnesses. This would involve a complete design change on every single boiler. I have already looked into this. Hope this helps.

Glenn

Unknown

Only

as a rule of thumb in determining placement of the equipment in reference to available combustion air. There are many variables that can have an effect on this. We also state to consult NFGC guidelines. It is in every manual.

Glenn

hr

Dan, the International Code

although is sounds like, is not a nation wide code. Most of the west is under Uniform plumbing, electrical, building, and mechanical codes.

I think there are still some areas under National Codes. And to further muddy the waters NFPA is trying to make a move to over take the Uniform Codes, and compete with the International to become the "one" code body. It's a power and money struggle!

BOCA and Southern Building Code used to apply here in my area, but the International Codes took over.

Unless of course certain jurisdictions chose to stay with their old codes, or even older code books.

The code issues in this country are crazy. Not only a state by state choice, but city and townships can use codes of their choice regardless of state adopted ones.

Then there are the local amendments. additions or deletions local AHJs make. The City of Springfield banned gas flexes, as they felt many were misapplying them. Go figure?

Not to forget how the individual inspector interprets the writing of the code he inforces. That's where it really gets mind boggling. Many inspectors in this neck of the woods don't know a boiler from a wash machine. Just not enough exposure or training, really. Not lack of desire generally.

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DanHolohan

Once again,

I have to commend you for the good and important work you do, Glenn. You're making a difference in this industry, and you're doing it calmly, logically, and intelligently. Thanks.

DanHolohan

How would

you remedy this if you were King of the Forest?

Unknown

Glenn, my reason for asking

has to do with the new NFPA 54 code which does away with Confined and Unconfined space rules and now wants calculations made based on air changes per hour factors. It is a somewhat more complex process than the confined and unconfined rules presented. It does however cause it to be necessary to more often than before use outside air for combustion.

Kal Row

COUNTERPOINT!!!

the pumps shipped with the boiler costs us very little in the total picture - and makes a great spare pump

in a hydronics setup – the low water cut-off should be mounted high to protect all the pumps in the boiler room as well – so there is just as much argument for not shipping it mounted on the boiler (of course, you will need put an auto-air vent above it)

as for “pump-away” – by definition “pump-away” is from the point of zero pressure change (where the exp tanks connects) and can be on the boiler return side as long as the expansion tank precedes it, the advantage of this method is that the boiler acts as a noise damper for the pump,
yes I know, most of us like to put the exp tank into the air separator past the boiler for the most dissolved air removal, as well as putting the fresh water feed there, to protect a hot boiler from a cold feed, however It can be argued – that putting the pump on the return after the exp tank increases the dynamic pressure across the boiler by 5-7 psi and will make the air separator work even better – as long as we stay below the boilers steady state pressure rating, ( relief rating ) I don’t see a problem with this

PEDRICK MECH

PUMP PLACEMENT

THE PROBLEM WITH THE PIPING DIAGRAM WITH THE RELOCATED EXPANSION TANK ON THE RETURN IS THAT ALL THE PRESSURE SUPPLIED BY THE PUMP WILL INCREASE THE PRESSURE IN THE BOILER, WHICH COULD POSSIBLE CAUSE DISCHARGING OF THE RELIEF VALVE DEPENDING UPON THE HEIGHT OF THE STRUCTURE WE ARE TRING TO HEAT. IT WILL THEN HAVE TO LIMIT THE VARIATIES OF CIRCULATORS THAT WE COULD USE TO THE LOWER HEAD VARIATIES OR REPLACE THE EXISTING RELIEF VALVE WITH A HIGHER PSI SETTING ( MORE EXPENSIVE ONE ). LOCATING THE EXPANSION TANK AWAY FROM THE BOILER IS A MUCH BETTER OPTION. BUT YOU ALREADY KNOW THIS.

THE REAL PROBLEM THAT I FIND WITH SUPPLYING THE PUMP WITH THE BOILER IS THAT IT MOST OF THE INSTALLERS BELIEVE THAT IT IS A ONE SIZE FITS ALL APPROACH. IT DOES WHAT THE CALCULATOR HAS DONE TO KIDS WITH MATH PROBLEMS. INSTEAD OF GIVES THEM AN EASY WAY OUT OF DOING THE PROBLEM. I SEE MORE GUYS USING THE 007 PUMPS ( ONE SIZE FITS ALL )ON INDIRECT HOT WATER TANKS THAT REQUIRE A MINIMUM FLOW RATE/HEAD LOSS THAT WOULD REQUIRE A DOUBLE 0010. THEY DON'T EVEN KNOW THE DIFFERENCE BETWEEN PUMPS. THAT IS A SAD TRUTH.

Unknown

Thanks Glenn as always

you give a complete and factual answer.

Unknown

King of the Forest

sometimes I feel more like a chipmunk coming out of my hole, Oh well!!

If I could I would like to see all the code producers sit down and look to consolidate many of the variety of codes across the land. As one who teaches code application and interpretation I find that many of them are the same and have different ways of saying the same thing. I guess that is to avoid plaguerism charges.

The meeting would really be to address their differences and iron out the difficulty of applying codes across the land. In this ideal world of me as "King of the Forest" I would like to offer them my interpretation of these many codes into one simple easy to apply process much as I try to teach it in class. Here in New England we have International Code in one state, National Fuel Gas Code in another and then Mass Code in another. I have them all in the same class room and teach all three at the same time simply pointing out some of the few differences. It is actually pretty amazing that they are so similar in many areas and that it is simply the Kings English that makes them sound so different.

That being said we now have local jurisdictions or as the codes call them "Authority Having Jurisdiction". Some of them really let that title go to their heads. They are at present an unsolvable lot as much of it goes to protecting sacred code turf in their little world. I guess in that world they are "King of the Forest". I have found in my travels and dealing with code officials that we can all come together and reason if we keep out cool and do not try to protect our own turf so much.

Last of all I am sure that in each area of the country there have to be special applications to resolve unusual situtations that exist in those areas.

If however we could have one code that fits all of the situations that we all face it would make things a lot easier. A sort of General Plumbing and Fuel code if you will with sections dedicated to specific issues each fuel presents. I know that the competition and money issue will probably make this certainly a pipe dream to say the least. But hey I have been having this dream for over 40 years now who knows someday it may come true.

hr

Small steps for small feet

First I would get all the states to adopt one code that worked in every town, city, etc. That would be a big plus for contractors that travel. At least you could know what to expect as you cross state lines.

Then every state would have their code of choice and any mods listed at their state web page. State crossing contracctors could research requirements at any time.

While I agree states should have the power to add or modify, it shouldn't break down to city by city WITHOUT that info (modifications)being readily available to any contractor. Again the www would be a good place to offer this info, city by city. Or attach the city mods to the states .org website.

Certainly there are valid reasons to modify. Water line burial depth is a good example. In Park City, Utah 6 foot was minimum, for good reason! I doubt Moab, Utah needs to bury water lines that deep. Same state big difference.

18" is the requirement here in my neck of Missouri!

I'm not sure we will ever see a one code fits all, or that we should. Too much politics and power struggle involved.

Think we will ever see a national drivers license or vehicle registration?

Julius Ballanco, PM mag columnist is the guy we need to quiz. He is in the know about this stuff

http://www.pmmag.com/CDA/ArticleInformation/features/BNP__Features__Item/0,2379,126074,00.html

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Unknown

Well

In answer to your "ALL CAPITALS" response, we have tested for this in the lab and in residential applications with relatively small pumps and a boiler with very little pressure drop, this is not a real concern. If it were a commercial system with a very large pump, then I would be concerned. Hope this helps.

Glenn

Unknown

NFGC

also follows those same parameters based on construction and where the combustion air may be coming from (indoors vs. outdoors). We state simply that the <50> rule applies to general everyday 2x4 construction with average infiltration. I agree that direct vent is the better way and trends are gradually steering that way.

Glenn

Unknown

That is interesting

I was was always led to believe by Ron R---llo that he was instrumental in requiring the LWCO's. Or at least that is what he told me anyway.

Glenn

Robert O'Connor_6

It should be noted

that the LWCO requirement in Maine predates the RI requirement of the eighties. - 1977.

regards

Robert

Unknown

Thanks Robert

I had not heard that before.

Glenn

Unknown

Keep in mind there may have

been more than one group influencing the decision. The gas company however would not give a meter to new installations unless they had a LWCO. This was over and above any other requirements in place at the time.

Robert O'Connor_6

I've

Been asking Bob Tonner to develop an aquastat LWCO combo.Think it would have any takers? The idea would be one probe for both.

I could really use it when i want to put a LWCO on an old boiler and don't want to break into the piping

Regards

Robert

ME

leo g_13

besides

in pri/sec arrangment, is there really a "return" or "supply" side?

Leo G

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DanHolohan

Yes.

The primary circuit has the compression tank and the primary circulator pumps away from that. On the secondary circuits, the point of no pressure change is the common piping, so the secondary circulators should pump away from that point.

Kal Row

except for multiple stateged boilers

where the exp tanks is in the secondary - so the primary return header is an efective pump away zone


another point - no one will probably admit to, the reason they ship boilers with the pump on the return - is that cooler is still better even for water cooled pumps - the manufactures doesnt know what temp you are going to drive it up to, so they put it on the return to protect against flash cavitation - which is not unlikly at 190+ discharge temps just past the flow-check

leo g_13

So

I have a radiant floor secondary and a DHWT, (which our drawings show supply off the primary and return after all other S/R's) secondary, can I put the compression tank beyond the last secondary return and pump away from that but "into" the boiler?

Or must the primary circ always be located before the first secondary supply take-off?

Leo G



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Kal Row

a pri/sec with DHW off the pri

is inherently a paralel primary

now - if you only have one pri-pump and use a prioriy zone valve arangement to select between heating and DHW, then you can indeed put the exp on the return just before the pri-pump attached to the boiler - but, if you have two pumps - then you have no choice, but to put exp tank after the boiler and the two pumps pumping away from there

ps dont forget to sprinkle your system with spring checks - otherwise the heat from the DHW tank will gravity migrate right out into the heating system - costly in the winter and really anoying in the summer - and can easily mitigate all the saving of a combined system

hr

Robert

I think i would prefer seperates, i feelo the LWC belongs above the boiler in the piping. protects more than just the boiler that way.

Ever seen the clever well Viessmann uses on their cast iron? It's a triple well that accepts the sensors from the aquastat, low temperature protection stat, and the temperature gauge, which is remote mounted on the panel.

I like that it has all these in the same (correct)location, and only requires one boiler tapping! any or all the controls could be changed without a drain down.

A pressure gauge is sent separately, which I also like as it can be mounted outside the jacket for easier viewing. Better quality psi gauge available when seperates are used, I feel.

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DanHolohan

Got

photos? ;-)

S Ebels

RE: LWCO's

I would like to see the manufacturers include just a wiring harness for a LWCO. Something you could plug into the boiler wiring and then run your wiring from the LWCO to the pigtail or whatever you want to call it. I realize this may require a little thought and engineering but the cost of implimentation should be negligible. A connector plug and a few feet of THHN wire. $2.00 tops at the manufacturing level. Put a jumper in the plug ala Honeywell aquastats when not used with a vent damper.

Little things like that can set a brand apart from the rest. Buderus for example has a spot for wiring in a LWCO right on their 2107 control. Makes it a 5 minute job instead of trying to figure out where to jump it in on every different boiler.

Unknown

It is just as simple

to install a 120v LWCO and wire it in series after the service switch. This way you will also interupt the circulators and there will be no concern about cutting into the boiler wiring. The 120v controls are, for the most part, the same price as 24v models. Hope this helps.

Glenn Stanton

Burnham Hydronics