Heating Help

adding a high water cut-off?

friends of mine often travel during the winter months and I suggested that they consider installing a high-water cut-off on their Safgard circa 1987 auto-feed because I know that sometimes auto-feed may fail open. They have a Weil McClain EG-65-P1 gas fired boiler. The EG Series Manual shows these tappings (below) are available currently he has everything tapped on the left side but according to the below, it looks like there may be taps on the right side as well. Can anyone here suggest how he can work with his plumber to install a high-water cut-off? He really wants to to do it since he did once have a boiler make fountains of his radiators. Thanks!

Boiler Flooding

You might want to take a look at this page on Gerry Gill's website. He has an interesting discussion on this.  http://www.gwgillplumbingandheating.com/webapp/GetPage?pid=500

When I travel in winter I just shut off my automatic water feeder as I have an low temperature function on my security system. The boiler shuts down, the temperature drops, the alarm company calls a neighbor, the neighbor calls the pro and the neighbor has a key to the basement. The neighbor also checks the boiler water height once a week.
- Rod

thanks...what is that

thanks rod .. what is that honeywell control shown on Mr. Gills PDF? It looks like a Honeywell pressure device, but I don't recognize this one with the large bottom diaphram .. it is specifically designed for Water (liquid) pressure rather than gas? Is thre a model of this device? Or perhaps it's just a regular honeywell pressuretrol .. thanks.

jpf

nevermind ...think i found it

i believe i found the pressure control device in Mr. Gill's PDF .. a Honeywell L91 .. however, it looks like a Honeywell L404F would serve the same function. They both handle non-corrosive liquid media .. this is the gateway into all the Honeywell pressure controllers .. http://customer.honeywell.com/Honeywell/UI/Pages/Catalog/SystemCategory.aspx?Catalog=Buildings&Category=Limits+and+Controllers_170&ChannelID={02CD9124-96F3-4A04-8EA7-1777CCCAD5B3}

My question now becomes one of piping .. and how the Safgard hydrolevel works .. a stack of water at a Dimension A of 28inches = 1psi .. that's awfully difficult for a standard pressuretrol to measure.

It looks like a better solution may be a Hydrolevel Tank Level Control..such as the 727 .. http://www.hydrolevel.com/new/index.php?option=com_content&task=view&id=23&bbc00e759205945763041cb2fb7e8b90=8defad515193547ce5430dba95e76854&Itemid=37

Using the Hydrolevel control, if water reaches 28in .. it can "deenergize" the auto-feed. Doesn't this sound like a better solution?

But how best to pipe it in? (see below sketch) Perhaps they can use the taps on the right side of the boiler marked "H" for gauge glass .. then run a high loop (to dimension A) of pipe from the lower tap with a 2 elbows and a close-nipple on the top of the loop returning back into the upper tap. And mount the 727 controller on the pipe leading from the lower tap. I cannot find an install manual or spec sheet for the 727 .. i will have to call them on Tues... unless someone has it. Then, once the water level is significantly high in the new piping loop, it will break the electrical connection to the auto-feed.

But it seems to be that these solutions only solve the problem of the probe LWCO or float LWCO asking for more water and therefore the feed continuing .. how often is the case that the LWCO is NOT asking for water (proper function) but the motorized valve fails OPEN of not fully shut.

jpf

Boiler Flooding

Quote:- "but the motorized valve fails OPEN (or) not fully shut" (or the valve seat leaks)

This was the reason that I just decided shut off the automatic feed water with a ball valve when I was away. I couldn't come up with what I felt was a viable solution. I had considered putting in a second electrically operated valve on the waterline. The downside was that it probably would stick and not function if you didn't "exercise" it at frequent intervals. (The one thing I am thinking of adding (for vacation setup) is a second LWCO (and possibly a emergency high limit (4 PSI) Pressuretrol)
- Rod

thanks...

thanks..Rod .. i appreciate your info and that you arrived in the same paradox as I

The human touch

The reason Steam systems lost favor is also in the human care they require. Turning off a valve is the best bet. A properly cared for system with proper piping is the only defense to system function.

and that's why ...

i tell the guys coming through giving me quotes that "no, i do not want an auto-feed" .. but possibly add it later (.. after my demise or sale of house.) but i would like a flow-meter on my manual feed system.

i think i've got it ...

how about piping in an F&T trap .. they are designed to release liquid when full .. you could add one sufficiently high and pipe it to a drain.

if the auto-feed puts in too much water, it opens and drains the water .. it doesn't help with shutting down the water, but it gives it a place to go when the boiler is overfilling rather than out the rad vents.

the F&T traps are steam rated and would pass air or be closed close under normal, not overfilled, operation ..

on occasion, they may themselves fill with condensate, and let it go into the drain .. you would need one of sufficient size to drain the amount being let in by the autofill .. i'm not sure how to size these.

i think this is a very clever idea indeed .. comments appreciated.

Ball Valve

It sounds to me that the F&T trap idea, while theoretically good, unfortunately would have the same vulnerability as the secondary water line solenoid. After sitting there inactive/neglected for several years will it work when it is needed?

In the past I've thought a lot about the auto feed problem and I always return to the thinking "simple is reliable". That's why I just use a ball valve. When I'm away the heat is turned way down so the boiler uses less water. I also raise the water level slightly to give it a bit more "reserve" and was thinking of adding a reservoir if more reserve was needed but this hasn't been the case with my boiler. 

As I mentioned earlier that my security system has a "no heat" function so the alarm company will notify me if the boiler shuts down. When I'm going away I let them know to notify my neighbor instead.  If one didn't have or want to bother with a security system it would be easy to setup a sensor /autodialer/text message notification that the boiler was in trouble. Even in the coldest weather you'd have quite a bit of time to respond before the house cools enough and damage was done to the waterpipes etc. The autofeeds are like a loaded gun in they have the potential of going off when you don't want them to.

If you are going to use a auto feeder I would highly recommend the Hydrolevel VXT. I have one though I have gone to manual use especially when I'm away. They have a string of safety features to help prevent flooding. They keep track of how much water is being used (even if you manually fill)  and are about as "bullet proof " as you can make an auto feeder.
- Rod

thanks rod ..

thanks rod ..

i would love to hear from folks with real experience with F&T traps to determine how feasible that are for a high-water overflow application. and how they might be sized in this application.

i've looked around a bit and the guts seem to be all Stainless Steel at least the ones here: http://www.spiraxsarco.com/us/products-services/products/steam-traps/float-thermostatic-steam-traps.asp#sb

You are looking for a foolproof system

but no such thing exists. You have me thinking now, what would I do if I was going to leave my house for several months during the winter. I'd probably turn everything off (at least the water) and hope for the best. I'd also google to see what others do.

Without further guidance, I'd turn the water off for the whole house - and drain whatever I could. I'd slightly overfill my boiler, set the thermostat to 55. I might even turn it off and drain it! A visiting neighbor is probably the most reliable backup (do alarm systems work if a tree takes down your power/telephone/cable lines?)

I don't think there is a right answer to your question, but I don't think adding anything will help. Just introduces one more point of failure IMO.

Edit: I'd also call my insurance company to see what they recommended or required.

Live in the tropics on the fuel money!

I have neighbors who drain everything and go south for the winter. The first year they did this it was a bit of a hassle as they needed to get their plumbing modified a bit and have a lot of drains and inlet valves added so they could blow out the water lines with compressed air. After the first year hassle they now can close up in a couple of hours. They work from a check list so as not to miss anything like adding anti freeze to the toilet bowels (they drain the tanks) and sink traps.
The only downside that I've heard to closing down a house is that if you have old horse hair plaster rather than modern dry wall, there can be moisture in the old plaster and it may freeze and form cracks.

These are old houses with practically no insulation with resulting high fuel bills. Several of my neighbors have found that they can rent in Florida or the West Indies for about the same as the savings on their fuel bill and be a lot warmer too!
- Rod

not looking for perfection but PRO feedback on f&t as a possibility?

at this point, i'm only asking if a F&T is a reasonable option from those familiar with using F&Ts on a daily basis since it seems like having a normally closed yet float operated overflow is something that makes perfect sense, would be easy to pipe, costs less than electronic control and may protect the rads from filling with water.

perhaps no one has ever considered using them in this function, but now that I have raised the point, i'm only asking for someone familiar with them to provide feedback to the consideration.

i'm sure the F&T companies would love to have them installed as an overflow solution/option on every installed boiler. if i'm not able to obtain considered pros & cons feedback here, I'll reach out to F&T manufacturers on Tues.

i'm completely clear that there are other more manually intensive, probably more foolproof, "this is what I do" solutions...but i'd like to concentrate on the ability to use an F&T in this manner.

thx.

i think you may find they ''dribble''

a little bit, which would be bad if your sending the discharge to the sewer..they are used in exactly the application your talking about when multiple commercial boilers are installed where one has the potential to be off line..the f&t is a good idea, but i would be concerned that it would dribble..on commercial jobs the discharge is sent back to the inlet of the feed tank..so its not really lost water..humm, i wonder if a 3/4'' vertical radiator trap pointing up would work, with its discharge then piped back down? shouldn't dribble then.. 

found this ..

i found this drawing on the net .. that mentions exactly what you say .. in multiple boilers, F&T used to prevent flooding ..

F & T trap idea

I don't think an F & T trap would work due to the relatively small size of the drain. I believe it would have an extremely difficult job in keeping up with the volume of water, unless you were to use a HUGE  F&T (which would probably be cost prohibitive).  Just my opinion.

thank you ..

thank you Mr. Gill and M. Downey ...

regarding the dribble .. do you think they will condense enough on their own to cause significant loss? the point here is that it will be mounted near-boiler and high ... so it should never really have any flow except for it's own condensation.

regarding a 3/4 rad trap pointed up .. would you consider that as an ADDITION to the F&T to prevent dribble .. or INSTEAD of the F&T? do you have a make and model of such a trap so I can visualize what you are referring to? (i found a Watts unit pictured below .. is this what you are referring to?)

regarding size ... yes, i know that the size factor needs to be large since it is expected to handle the load of an inbound auto-feed .. they have "calculators" .. but I really don't know how to fill in the values .. http://www.spiraxsarco.com/us/resources/calculators/pipes/single-discharge-line.asp .. any help would be appreciated .. i'm sure they make ones which are big enough, and would like to at least understand the costs involved. $300, $500, $1000?



thx

f&t rated for 5,400lbs/hr

i found this f&t rated for 5,400lbs/hr .. but i'm not sure how to translate that to gallons/min or more specifically, domestic water at about 60-90/psi pressure.
http://www.statesupply.com/displayItem.do?sku=SG1112

in TLAOSH, dan says that 30lbs = about 3gal...so this may do 540gal/hr ?? that would be about 9gal/min .. is this roughly what NYC single family domestic water may run at?

thx

Would this work?

What if you installed a probe-type LWCO somewhere in the top of the boiler header piping. Wire it to the autofeeder so that it opens the circuit when it detects water (normally closed circuit, opposite of how it works in the boiler). If your autofeeder goes berserk, this should cut it off when the boiler header floods, but before water gets into the mains or rads.

My CycleGard LWCO can be wired for normally closed or normally open operation, so that part can be done. Not sure if the probe would be damaged by long-term exposure to steam.

Just a thought.

Cheers,
Mark

good idea .. but..

that doesn't solve for the case where your auto-feed is not asking for water (it has been satisfied) and yet the motorized valve has crud in it and remains open or partially open .. as well what is the manual bypass valve is leaking and the auto-feed valves are shut tight .. what i'm looking for at this time is a way to provide an overflow regardless of how the water is getting in .. similiarly .. what if an indirected boiler is leaking domestic water into the heat exchanger or if the tankless coil is leaking into the steam chamber. those are 4 things that may cause boiler flooding but can't be solved through an electronic method.