McDonnell & Miller Water Feeder Clicking

Eagle1017

Hi - I have a McDonnell & Miller Series WFE Uni-Match Electric Water Feeder on my Burnham gas fired steam boiler. Over the last month or so I've noticed when the boiler cycles off the water feeder makes 3-4 very loud clicks. It would be fine but the noise reverberates through all the pipes and is pretty loud upstairs. It wakes my family up at night. Has anybody experienced this before? The water feeder seems to be working fine otherwise but not sure why it has started clicking so loudly. Any insight would be appreciated. See attached picture.

Mark N

Is the water feeder cycling the boiler off and feeding water? If that is the case find the leaks. The constant adding of fresh water will eat your boiler. The banging could be high water pressure rattling the pipes when it feeds. Make sure the pipes are secure. Have you been in the basement when it happens? What have you observed?

Mark N

It looks like it feeds right into the top of the hartford loop. That is not right. It should feed into the wet return.

Eagle1017

I don't believe so. I believe the thermostat is cycling the boiler off which triggers the water sensor to test the water level, right as that is happening the auto feeder makes loud metal on metal clinking sounds. I've observed the boiler cycling off, the water sensor turning on and clinking coming from water feeder/water pipes near feeder. I don't believe there are any leaks. I'd say it only actually feeds new water to boiler once or twice a day. See attached picture showing lower portion of boiler.

KC_Jones

If you are feeding water once or twice a day that is a massive amount of makeup water and generally means you have a leak. Unless you are removing a lot of water from the system that feeder probably shouldn't feed more than once a month...if even that much. That much fresh water will destroy the boiler in a hurry. As far as the clicking it shouldn't make any noise unless it's actually feeding water and even then should be very loud. I think it has already been mentioned it seems as though you have a lack of pipe supports which will cause noise. Generally it's not so much the valve making noise it's the pipes rattling making noise....especially on solenoid valves like that and in washing machines.

Mark N

If your feeding once or twice a day you've got leaks. Check all your vents, check the packing nuts on the valves. It looks like you have pipe running on the floor. Does it go under the floor anywhere? If it does assume it is leaking.

Mark N

If you need to have a water feeder I would suggest getting a HydroLevel. It has a built in water that tracks the amount of water feed into a boiler. I also have a Burnham Independence boiler. My water level drops a 1/4" to a 1/2" a month. That is like a quart of water. If your dropping enough to feed once or twice a day your losing gallons a day. How new is your boiler? Was the old one replaced because it rotted out?

Eagle1017

The feeding I am talking about is for about 10 seconds, it isn't much at all. No I don't have any underground pipes. It is a brand new boiler installed in November. Yes the previous boiler rotted out.

Abracadabra

Does it make the noise when manual feeding? Noise at start of feed or when feeder shuts off?

Mark N

Do you have slow returns? Do you ever have to drain out water because the level is to high? Your old boiler rotted out, do you know how old it was?

KC_Jones

The point is it shouldn't feed daily...no matter what. There is a problem. It could be a severe surging issue causing feeding during operation. Has the boiler been skimmed? Sometimes they will surge to the point of hitting low water then feed, but stop quickly because the boiler shuts down and the water level returns to normal. Usually for these situations there is a feed delay built in so it gives the water a chance to return before feeding. As MarkN suggested possibly a slow return to the point it starts feeding then suddenly the water comes back? It sounds like the issue is more complicated than just a noisy feeder.

Eagle1017

No it does not make the noise when manually feeding. It happens right after boiler cycles off and sensor is testing water level. Yes, I believe I have slow returns - at the end of the mains there are down pipes to the return lines which are low/on the basement floor. No I never need to drain it out because it is too high - never had that issue. I can see all the mains/returns/radiators, I would be very surprised if there was a leak. Yes, I skimmed the boiler a few weeks ago, I'm still seeing a fair amount of surging.

Eagle1017

The old boiler was 20+ years old.

Mark N

If you're still surging you have more skimming to do. Do you have a cycle guard LWCO? Is this happening when it shuts you down to do a intermittent water test? Turn off the water feeder and see how long it takes to go off on low water. Keep an eye on it because it is too cold not to have heat. It should take many weeks to go off on low water not hours.

Abracadabra

Eagle1017 said:

...Yes, I skimmed the boiler a few weeks ago, I'm still seeing a fair amount of surging.

i got a fever.. and the only prescription is more skimming

KC_Jones

When I did mine I skimmed until it seemed good, then did another skim just to be sure. Surging wrecks havoc on the boiler and system operation.

Eagle1017

Yes I have a cycle guard LWCO. It could be for an intermittent shut down, not sure. How do I shut off the auto feeder? I think the boiler will go to low/no water quickly. At the moment the heat is running and the water vile shows no water - it seems like it only takes minutes for the boiler to turn the water in the tank to steam - is that normal?

Fred

Not Normal at all. I suspect you need a very, very good skim. You said you have skimmed it. How are you doing that? If you are draining water out of the spigot at the bottom of the boiler, that's not a skim. You have to skim, very slowly from a skim port above the water line. It takes several hours to do properly and may take several sessions.
EDIT: Besides that, the "Lowest Permissable Water Level" on your boiler is not mounted where it should be. On a Brunham, it should be 2/3's to 3/4's of the way up the sight glass. Make sure your LWCO is working. There is no way the glass should be empty and the boiler still running.

KC_Jones

That is surging. It doesn't empty the boiler when it steams the water level should have minimal drop in the glass. If it is dropping that much you still have plenty of skimming to do, or the pressure is too high. My guess would be skimming.

Eagle1017

I removed the pressure release valve well above the water line and slowly added water to boiler until it barely dripped out. I did for a few hours. I need more?

Fred

Yes, you definitely need more and you may need to do it several times at maybe 1 week intervals until the water in the sight glass has minimal bounce, maybe 1/2" to 3/4". The boiler water should not drop much below the middle of the sight glass during the entire heat cycle. Post some pictures of the piping around the boiler. That water is being pushed out of the boiler for some reason. It may be because it needs skimming but it could also be because it is not piped correctly.

Eagle1017

Here's some pictures. If it helps you to diagnose I have lots of water hammer.

Abracadabra

Abracadabra said:

Eagle1017 said:

...Yes, I skimmed the boiler a few weeks ago, I'm still seeing a fair amount of surging.

i got a fever.. and the only prescription is more skimming

skim the boiler more.

Fred

The piping looks pretty decent actually. That water supply line definitely needs to be taken out of the top of the Hartford loop, a plug put in its place and the water line piped over to that fitting at floor level that has a plug in the top of it.
Also, looking at your last picture, the Main taking off to the right of the screen looks like it may be pitched down towards the header. If that's is the case, that is probably one source for water hammer. It needs to be pitched up, away from the header. I can't see the other Main but if it is pitched towards the Header, it too needs to be raised. Probably when they connected to the Boiler/header, they pulled the mains down.
Check the pith of the Mains and run-outs to the radiators anywhere else you might hear hammer and make sure they are pitched correctly.
Skim somemore and take care of those relatively minor piping issues and it should fix things.

Eagle1017

Thanks. Any ideas on the clinking from the water feeder?

Fred

If I had to hazard a guess, I'd say it may have something to do with the steam/temp that the water supply pipe is exposed to by being tied into the top of that Equalizer. I'm betting if you move the water line to that return, the clinking will disappear. Probably more noticable now because the temps have been colder and the boiler is running a little longer.

Abracadabra

How about a video of the noise? Maybe it's just expansion noise?

Eagle1017

Thanks. I'll try to send a video soon.

Eagle1017

Also - I've read the articles on this site on skimming but still not clear to me why some oil film would cause surging. Can somebody please explain? Why would oil in the boiler water cause my boilers water to quickly boil/leave the boiler while a fully skimmed boiler would drop just half an inch when running?

KC_Jones

The oil doesn't allow the steam to escape the water properly. The oil makes it so the water boils with large bubbles not small. The larger bubbles contain a lot more steam and therefore more energy. This energy then sucks the water out of the boiler with the steam. The best way to see this is get 2 pots, put them on the stove put water in pots add a skim of oil to the top of one of the pots and then boil them both. You will clearly see the difference in the manner in which the bubbles break the surface. If things are piped correctly and skimmed correctly you should get very little water leaving the boiler if at all. The idea of the header and equalizer is to separate steam from water and let the water go right back into the boiler. Here are some interesting videos that show you what goes on inside the boiler not necessarily surging, but it will give you and idea how violent it is and why things must be just right to work correctly.
http://forum.heatinghelp.com/discussion/152119/steam-boilers-the-inside-story-lots-of-videos

sbachman7117

I have the same Uni-Match Waterfeeder and it is doing the same snapping that the OP mentioned. Like the OP, I have a larger issue that is causing the water to feed too much. (In my case, it's an obvious leak.) However, I still hope to understand why the water feeder is snapping and whether I need to repair it. The snapping happens when the feeder valve closes. It happens whether the feeding was triggered by the LWC or by me manually pressing the button. There is normal noise of flowing water while feeding, followed by about 30 seconds of random clicking, snapping and banging after the valve shuts (or should have shut...) There is a B&G FB-38 pressure reducing valve immediately upstream from the Uni-Match. It's possible that the noises are coming from the FB-38, but I don't think so. I thought I had fixed it when I cleaned the filter screens on both the Uni-Match and the FB-38. It stopped for a day or so, then came back. I cleaned them again and the noise remained. The noise sounds a bit like water hammer typical of a washing machine solenoid, but is more of a mechanical/metallic clicking and is goes on for quite a while. Any thoughts? Thanks!

sbachman7117

Also, my feeder is far enough from the boiler that it is not getting hot, as an earlier poster speculated might be the cause.

Fred

It sounds like a solenoid might be failing or the water pressure is still to high???

KC_Jones

Is it possible there is some weird resonance between a back flow preventer and the auto feeder? So when the feeder shuts off it's pretty common for it so send a pulse backwards down the water line (fast acting valve). If this "pulse" hits a backflow preventer then what happens? I am not well versed when it comes to backflow preventers so I can't say for sure, but I wonder in these situations if there isn't some resonance being set up between the 2 devices. Basically a pulse being bounced back and forth between the 2. Even if it was I would still say it's a pipe support issue of some kind. I have an Auto feeder and backflow preventer with well secured pipe and mine is silent except when I feed it (that's just water flowing sound).

sbachman7117

Thanks Fred and KC_Jones. I appreciate your thoughts. In my case, the FB-38 pressure reducer is between the backflow preventer and the feeder. I expect the FB-38 would provide some isolation and prevent resonance between the feeder and the backflow preventer.
I messed with the adjustment screw on the FB-38 a bit (1 turn in either direction) to see if a pressure change would eliminate the snapping. It did not.
A bad solenoid seems like a good guess, but it doesn't sound like the shuddering noise that my dishwasher fill valve made when it died. It is very odd.