Auto-feed

lstevens

I spoke with a potential contractor in my quest for a replacement Gas/Steam Boiler. In the course of the conversation, told him that there would be an elderly person in the house, often alone for many weeks at a time, and that I would want an auto-feed. He said he doesn't "trust" them, that they will all fail sooner or later, and that he won't put them in due to liability. Is he right? Shouldn't potential liability be my choice? I also have concerns with NOT having one, as the house may be unoccupied for a month or more during the Boston winter, and I don't want to risk freezing.

KC_Jones

Opinions vary on this subject. I think most will agree it isn't technically a "safety" device it's a convenience item. The boiler should still have someone "checking in" on it regularly. I don't have vast experience, but I don know the one on my old boiler was working perfect and it was 32 years old. I only replaced it because it didn't have a water meter to monitor the amount of makeup water. Your concerns are valid if the house will be empty like that. I would still have someone checking in on it occasionally. If you get a leak for some reason and the autofeed is keeping the heat on you still have water leaking in the basement which isn't good. Freezing is one thing, flooding the basement is another possibly just as damaging problem. I mainly installed mine for the meter, it has never fed automatically and probably never will.

ChrisJ

I agree with all that @KC_Jones has said and would like to add I'd have a wifi thermostat there if I was going to be away for that long.

This way you can check your indoor temperature from time to time.
Insist on a Hydrolevel VXT feeder if you want a feeder.

Personally, I don't have an autofeeder. The boiler that was in the house when we bought it did, but I never put one on the new boiler.

As KC said, you should be manually feeding the boiler anyway and it should be done when the boiler is firing so dissolved oxygen is driven out as fast as possible. I typically remember in the back of my mind that I needed to add soon and when I hear the thermostat click on I'll go down the basement and open the valve to feed water slowly. This way, all of my water is added right at the start of a cycle so I know it's boiled before the boiler shuts down.

Jamie Hall

@ChrisJ and @KC_Jones 's comments illustrate rather well one of the two points of view. The other is that while the auto-feeder is not, strictly, a safety device -- that's the job of the low water cutoff or cutoffs -- it is more than just a convenience when it is installed in a situation where the occupant can't or can't be expected to get down to the basement to check the level and add water manually -- which in my humble opinion applies to the vast majority of homeowners.

It should have a meter on it, but that is common enough now that it shouldn't be a problem.

Regardless, the house as a whole should be checked weekly if someone isn't there! It should be checked at least daily if there is an elderly occupant home alone -- but that, I would think, should go without saying. There would be no harm to asking the check person to go to the basement and note the reading on the water meter on the feeder, but it would be asking a bit much of a home health care type -- or your third cousin once removed -- to check the gauge glass and add water as needed.

On the wifi thermostat... well... um. They are getting to be more popular. On most of the ones which I have seen, the security is somewhere between minimal and zilch, and if it is connected, as it would be, to the home computer system all I can say is that I hope you have really top end firewalls on that system... both upstream of the router (between the router and the modem) and downstream (between the router and all other connected devices -- one on each computer), and the wifi network protected by a really solid password, changed, if not daily, at least weekly.

Paul48

I know the LWCO on my hot water boiler has alarm contacts on it. I could hook it up to an auto-dialer, if I chose to. Maybe that is an option. Even with an auto-feed, you would know if it was adding water too regularly.

Leon82

I've seen diaphragm feeder pumps which have a small tank and aren't damaged if run dry. In the event of a large leak you would only pump a gallon or two instead of a constant flow. I'm not sure if it would be a good fit for this application.

Fred

I too add water to my boiler manually. I am somewhat neutral on the value of a water feeder but there are circumstances when they can be helpful. It sounds like in this case, the value of having one is greater than the risk of it failing. Naturally, the boiler should be checked regularly to make sure all is well and the Low Water Cut-off tested at least once each season. Water feeders are almost always installed with a manual by-pass valve so that the boiler can be fed either manually or automatically so you have either option if you install one. Just be sure things are inspected and cleaned/tuned each season, including the water feeder. When they fail, it is usually failed open, allowing water to seep past the shut-off valve and usually after a few years of operation.

jumper

I don't trust them either.

SWEI

A once per month visual inspection of a metered auto-feeder in this situation does not seem particularly reckless to me.

george_42

years ago my neighbor went south for the winter and before leaving he turned the thermostat down to it`s lowest setting. then we had a severe low temp and one of his baseboard units froze and started leaking and his auto fill worked perfectly and filled the basement till the boiler failed and then continued to work until the ice in his ranch house was coming out of the windows. nice thing to come home to.

Jamie Hall

george said:

years ago my neighbor went south for the winter and before leaving he turned the thermostat down to it`s lowest setting. then we had a severe low temp and one of his baseboard units froze and started leaking and his auto fill worked perfectly and filled the basement till the boiler failed and then continued to work until the ice in his ranch house was coming out of the windows. nice thing to come home to.

I doubt that anyone here is suggesting that a house -- or any other building -- should not be checked on a regular basis, preferably in person, although there are sophisticated remote sensors (which don't come cheap if they are secure and reliable) which can do it for a building which cannot be watched.

I would add that in the case @George cites, the device may not have been an autofeeder, but a PRV, which is somewhat more common on hydronic installations. I would further add that he who leaveth a house in the north and goes down south for the winter and doesn't turn everything off and drain everything may just be a candidate for a Darwin award?

I think, rather, that the suggestion to put an autofeeder on a boiler serving a residence occupied by an elderly person simply makes good sense for the health and safety of that person.

jumper

Jamie Hall said:

george said:

I would add that in the case @George cites, the device may not have been an autofeeder, but a PRV, which is somewhat more common on hydronic installations. I would further add that he who leaveth a house in the north and goes down south for the winter and doesn't turn everything off and drain everything may just be a candidate for a Darwin award?

At the very least turn off water supply. If system loses so much water that heat goes off,there's some chance that pipes won't crack

lstevens

Thanks for all the pointers and advice! :-) Seems to me that a Hydrolevel VXT makes sense if intelligently used. However, I AM concerned about the possibility of the system getting stuck in the "water on" state, and flooding the upstairs. In searching, I found this:

http://www.gwgillplumbingandheating.com/webapp/p/500/the-peril-of-automatic-water-feeders

Is this something that a boiler installer should be able to do for me? Anyone out there has done this? Is there a better way to accomplish this?

Paul S_3

the VXT locks out if it feeds too much water.....yes the installer should be able to do that setup....i guess set it around 1.5 to 2lbs that would limit water stacking up to about 3 to 4 feet above the control.... your system operating controll (ptrol) would have to be set lower preferably a vaporstat set to 10 ozs

lstevens

So, you're saying the VXT essentially has the interrupter capability built in an that I don't have to worry about potential flooding? If that's the case, my problem/concern is solved!

Paul S_3

Where it says lockout flood protection....but @gerry gill idea seems great as it adds a second safety

Fred

The interrupter is attached to the wiring between the LWCO and the water feeder with a sensor attached somewhere in the piping/boiler. That switch will work with virtually any electric water feeder. The interesting thing about that article is that it is clearly a "sales Pitch". More often than not, water feeders will continue to feed water to the boiler, and consequently flood it and perhaps fill it to a point that water spews out of main and radiator vents because the water valve will not seat properly, due to wear or crud or the solenoid will fail and allow the valve to remain open. That switch won't fix those situations. That's why it is so important to periodically check the system, boiler, LWCO, Feeder and piping to ensure everything is in good working order and to have maintenance done annually.

BobC

That's a great way to protect yourself against the auto-feeder getting hung up but there is another failure mode. Sometimes the seat on the valve inside the auto-feeder does not seat properly and water will weep into the system slowly and that will eventually fill the steam piping and radiators with water.

i would add an alarm onto the contacts that disconnect the feeder so someone is aware there is a problem.

Bob

lstevens

So, there is no Fail-Safe for this kind of an automatic feeder?

Paul S_3

What about a normally open zone valve ....wired in with a pressure controller....water starts to fill closes contacts and power closes the zone valve?or a flood protection valve and extend the sensor/s near main vents.....i guess anything can be built

BobC

It's a mechanical device and mechanical devices will eventually fail. Auto water feeders are a convenience but they can not be ignored, adding the pressure switch to stop the flow of water and warn you about it should make it more foolproof.

Bob

Fred

As BobC suggests, an alarm along with the interrupter is an option or you may be able to get a "Normally open" electric water valve installed in the supply to the water feeder and have the interrupter wired to that valve. No power, valve closes. Of course that valve can and will eventually fail too but if it does the auto feeder water valve will be closed unless there is a call for water. The likelihood of both valves failing at the same time are about as slim as it can be.

Aaron_in_Maine

Check with your homeowners insurance about the empty house scenario. I have a customer who winters in Florida and his insurance would not accept a wifi thermostat as far as monitoring. He had to have a land line installed and I put in a freeze alarm auto dialer. That was the only way his homeowners would not cancel his policy.

lstevens

Fred said:

As BobC suggests, an alarm along with the interrupter is an option or you may be able to get a "Normally open" electric water valve installed in the supply to the water feeder and have the interrupter wired to that valve. No power, valve closes. Of course that valve can and will eventually fail too but if it does the auto feeder water valve will be closed unless there is a call for water. The likelihood of both valves failing at the same time are about as slim as it can be.

Sorry if it's a "dumb" question, but will this solution help if the LWC malfunctions and keeps calling for water?

Paul S_3

If the low water cutoff malfunctions the vxt programmable water feeder protects against that...the "normally open " electric water valve adds an additional safety to this

Jamie Hall

Do try to keep in mind that there is no such thing as a fail proof mechanical design. Period. It doesn't exist. Now one can reduce the probability of a failure in a number of ways, and one can reduce the consequences of failure. Reducing the probability of failure from the mechanical standpoint lies in two approaches, which are complementary: first, invest in quality devices and installation. Second, incorporate some redundancy in the design. Thus, for an installation such as what we have here, we want the best quality auto-feeder we can get (and the Hydrolevel VXT is in that class). Second, perhaps we feel a need for redundancy, so as others have suggested we install a fail closed valve with a manual reset, also of very high quality, in the feed line. Having done that, however, we now need to protect against low water, and a redundant manual reset low water cutoff becomes mandatory (set, of course, at a lower level than the regular LWCO. Now we have a problem: we're pretty sure that a) the auto-feeder won't overfeed the boiler or, if it does, our fail closed valve with shut it off and b) if the feeder fails to feed, the boiler will turn off.

Please observe that is also possible to come up with a fail operational design of similar reliability -- with considerably greater expense and complexity.

OK... now we can be reasonably sure that the boiler won't overfill or dry fire.

But... what happens if the power goes off completely? What happens if one of the redundant safeties shuts things off? And then it gets cold...

Um...

You have two choices: Well, three. First, and best, is that someone competent checks that all is well at least daily -- and I don't mean an auto-dialer or wi-fi thermostat (that's just something else to fail). Second, drain the water out of the building if it is going to be left for more than 24 hours (perhaps, if well insulated and not too cold in your parts, as much as 72 hours might be OK. Not in New England...). Third, live with the consequences of failure... and hope it doesn't happen on your watch.

lstevens

Is there a better unit than the Hydrolevel VXT (regardless of price), or is that one as good as it gets?

Fred

That's about the best one in the market. McDonnell Miller makes one also, but it does not have a water meter built into it, which is an important feature for tracking excessive water usage (indicative of a leak). They all operate pretty much the same way. There just isn't anything mechanical that won't fail, at some point. Use the VTX and add the redundant valve if you are especially concerned. The VTX will most likely go several years without failing. It's anyone's guess when it might fail.