System GAINING water

4Barrel

Got an odd situation. My steam system is actually gaining water. First noticed it in the early fall, the entire system was pretty much filled, after sitting idle all summer. I figured this was b/c the autofeeder (Hydrolevel VXT-24) had been powered down, and its valve was not fully shut. Now that the systems been functioning for about 6-8 weeks, I've found that the water level steadily increases when the system has been sitting idle (after accounting for condensate return). I've narrowed it down to either 1) the ball valve shut off in the supply line that runs parallel to the VXT, or 2) the VXT itself. I don't think it's the ball valve.



Has anyone had any experience with the VXT's failing in this way, and are there a recommenced procedure for troubleshooting that unit, or is the unit itself shot? It's only two years old.



Input welcome and appreciated.

Maine Vent

VXT 24 ????

Just a homeowner, with a new system. I had my old VXT off this summer while waiting for new sytem to go in. I could look into the water feed side of the copper tubing, an I saw a lot of calcium built up and krud. My VXT was on a 6 section V9 Burmham that used over 900 gallons of water the last 3 years. This thing got a workout, and before I reinstalled in on my new system I tried to purge as much krud out of the line that I could get to. Sounds like a auto valve is not closing all the way, or something is in the way. Hydrolevel has been helpfull with me on another problem, call them.

Long Beach Ed

Feeder Feeding

If a feeder is installed properly, it will have unions on each side of it.  There will also be a union after the manual feed valve.  This is how McDonnell Miller taught us to pipe a feeder so we could determine the source of exactly your problem.



Open the union under the manual valve and you'll know if that valve's leaking.  Open the union after the feeder and you'll know if the feeder is passing water.  Simple.   Without the unions, cut the pipe.  (See why they told you to install unions?).



That said, here's our sad experience with Hydrolevel VXT's: 



They fail.  About 40% of the ones we bought have failed in the first two years.  But all of ours have failed shut.  They stop feeding.  Thank God none have gone on feedwater marathons.



The most likely way for that to be passing feed water when closed is if there is debris in the seat which is holding the valve open.  Have you cleaned out the strainer?  Look at the manual and see if the strainer is full of goop.  If it is, you may have a problem.  If the control is improperly piped to feed from a hot water supply, the valve with foul with lime.



Don't rule out another cause.  If you have a tankless hot water coil in the boiler it may be leaking domestic water into the boiler. 



Good luck with your search. 

4Barrel

good suggestions

thanks for the replies.

the first season i used it, the VXT did feed fairly often as I worked out a lot of kinks in the new system. last season, not often. but then i had the issue over the summer.

def not piped to hot water supply.

yes, i piped it w unions -- see pic -- not a very pretty job, i know.

i test the feeder every year on turn up under a couple scenarios to make sure it feeds. good to know that i'm on the right track with this, and not to get lazy about it given the failure rate mentioned.

good suggestions on isolating the leak, and will give hydrolevel a try if i get stuck.

will post once i find the culprit.

4Barrel

it's the VXT

after a few calls in Hydrolevel, we confirmed the valve is not fully shutting. and of course, i am just two months out of warranty. i'm trying to work with the supplier to see if they will petition hydrolevel to honor the warranty nonetheless (hydrolevel seemed open to this, but we'll see). wish i had paid more attention to this when i turned up the boiler in the early fall. amazing that a $250 part only lasted two seasons. very disappointing.

BobC

I would not use them

Has anyone taken one of these VXT's apart to see whats going on? It sounds like questionable milling in the valve parts. I'm hearing a lot of problems with reasonably new parts. I'll bet it's a Chinese supplier substituting parts without making sure they are viable replacements for the original specified parts, just get the things out the door at any cost.



It's just another reason I will never allow anything but a gate valve to feed water into my boiler, that valve is over 30 years old now. I record the amount of water I add in a log (inches of water in the sight glass - usually in 1/2" increments) so I'll know if anything changes.



i can understand that auto water feeders are a necessity for some installations but for an owner occupied building forget about it.



Bob

Jean-David Beyer

I will never allow anything but a gate valve ...

I am a homeowner, not a professional plumber or heating professional. But I have done quite a bit of plumbing work on my house, mostly soldered 1/2 inch copper tubing and a litlte PVC drain pipe from a double sink.



When I first put in a photographic darkroom, I installed a gate valve for the incoming hot and incoming cold so I could shut everything down if necessary. I also put in three gate valves when I decided to run the cold water supply to my electric hot water heater through the unused coil in my boiler. Those valves in case I regretted using the coil (leaks, etc.). Very soon those valves deteriorated to where they would not shut off completely. I later replaced them with ball valves and never had any trouble after that. It is true that I got those gate valves from a big box store (I had not discovered where a plumbing supply house was that would sell to those not in the trade).



My question is: are there better gate valves available than the ones I got? Mine were made in Italy (not Caleffi). Nowdays the big box stores sell mostly Peoples Democratic Republic of China stuff that seems even worse. My view is that in any plumbing I do, I would use ball valves instead of the gate valves I had in the past.



The only plumbing abuse I have in my house now are five ball valves where flow balancing valves should be. But they may last as long as I do.

BobC

Not easy finding good parts

My old gate valve is a Watts and seemingly well made, I've seen some supposed gate valves at HD that I would not buy if I had any choice in the matter. I'm lucky that my local hardware store seems to carry some pretty good valves, not cheap but if they last who cares.



If I had to replace the Watts I would probably go to a ball valve but I'd be careful of where it was made.



Bob

Long Beach Ed

Gate Valve

Watts = Chinese.  Most won't pass a pressure test.  Many NYC inspectors don't permit them (or any Chinese valve) for this reason. 



The proper way to pipe that VXT in the photo is to include another union below the bypass valve.  By opening that union, you can tell if the bypass valve is passing water when closed.   I see a coupling under the valve -- perhaps where someone cut the pipe to check the valve.

icesailor

Gaining Water

In my opinion, the way that auto-feeder is feeding is a bad design.

Basically, its like a toilet ballcock. 50 years ago, a float lever let the water in when the water level dropped. When the level was high, it shut off. If water was leaking by the flush ball, the ballcock would leak water at the rate of the water leaking past the flush ball. The water slowly leaking past the ball cock washer and seat will wear out the washer. New ballcocks are line solenoid valves. When the water in the tank drops to thr\e trip level, the valve snaps open. When it is full, it snaps off. If a toilet tank is leaking, I will get a complaint of the toilet running in the middle of the night.

If boiler feeders fed like this, you would probably get water hammer. The valve should have replaceable seat and washer assemblies.

If you read the instructions for M &M feeders, they tell you to install the unions so you can check it for leaking. They also make it easier to replace.

4Barrel

missing union

yes, there should be a union below the by pass, excellent point. when i opened up the union below the feeder, that's where it was leaking, but, of course, that doesn't mean it's not also leaking at the by-pass... a union below it would rule that out. on my list of to-dos.



w/r/t to the feeder, if this was a year ago, i'd be much less confident in taking it out of the loop. and even though that now the system is working well, and i think i will have minimal make up water, it provides a sense of security (perhaps false). i'm hoping hydrolevel comes thru and gives me a new part (which, undoubtably i'll have to replace in two years).



thanks for the informative replies!

4Barrel

Hydrolevel comes through

Nice concluion to this issue:  I was getting the run around around from the supplier and their wholesaler, etc, etc, so Hydrolevel stepped in, and they are sending me a new unit. They clearly made an exception for me, since the unit was a couple months out of warranty. Hopefully the new one will last more than two years :-)

Long Beach Ed

Hydrolevel

We've found them to be a good company.  The problem is imported electronics that are undependable. 



While we've had half of the ones we've installed fail early in their lives, the ones that held out are still working years later.  Hydrolevel also always made good on their products with us.