Weil-McLain 88 series 2 commercial Boiler waterline

temporarystress

Hey guys, as the title says, i have a commercial boiler and im having an issue in which the boiler is overfilling with water. Ive replaced both the water feeder and the low water cut off as well as clogged wet returns. None of my 29 units have heating issues at all and i can't find leaks coming from not one apartment.

temporarystress

here's another pic of the boiler itself

JUGHNE

Have you done the broken union test on the feeder?
Or leaking bypass manual fill valve even though it looks closed.

temporarystress

JUGHNE said:

Have you done the broken union test on the feeder?
Or leaking bypass manual fill valve even though it looks closed.

i believe that's what the plumber that came yesterday did. I had 2 different companies come this week, one suggested that most likely its the low water cut off. I then had another company come do the installation since I wanted this done ASAP and he suggest that the placement of the low water cut off itself is way too low.

Jamie Hall

I don't see anything wrong with either the autofeeder level or the low water cutoff. The only way a boiler can overfill is if something allows water to get into it (doh). So. First thing to check: is there a time delay option on that autofeeder? If there is, set it to longer if you can. Is there a feed volume setting? Check that and try various options if there are any.

Check -- does the autofeeder feed a reasonable amount and stop? They don't always...

Next trick -- bring the boiler water level cool -- system off -- to about where you have it in the pictures. Turn off the manual feed to the autofeeder and the bypass (I'm assuming there is one). Turn off the boiler. Mark the water level and let it just sit there for half an hour. The water level shouldn't budge. If it does, either the autofeeder or the bypass simply has to be leaking through. If there are isolation valves (I hope) on the autofeeder, close them and see what happens. Water still rising? Bypass is leaking. Water steady? Maybe the autofeeder. Open the water feeder isolation valves and close the bypass.

And so on.

The Steam Whisperer

If someone is throttling one pipe steam radiators by partially closing the valves this can cause the boiler to overfill because water gets hung up in the radiators until the boiler shuts down. Usually the water feeder added make up water during the heating cycle and then the water comes back and floods the boiler.

JUGHNE

Is that a working water meter on the CW feed and does it get read everyday?

If 2 pipe sometimes TRV can lock water up in rads to return later.

How do you do DHW? A tube in shell could be adding DHW thru pinhole. Any heat exchangers at all?

Only 1 boiler connected?

Gravity return...condensate pump or feeder pump?

ScottSecor

Just a shot in the dark here:
I'm guessing during a normal cycle the boiler water takes a long to return to the boiler. During this delay, the boiler starts to get low on water and calls for some water, automatic fill valve adds water and burner continues to operate. All is good for the moment. Then when the thermostat (outdoor reset control, etc) is satisfied, the condensate finally returns to the boiler. Unfortunately, the boiler is already full of water and begins to over fill. Every cycle may only add a quart or two, but after fifty or a hundred cycles the boiler is now flooded. We see this often with these types of mechanical feeders.

Another thing we see often is too much chemical in the system, this can wreak havoc on the water line and the end result might be similar.

Finally, if the boiler water is very dirty (or oily) the same thing could be happening with an unstable water condition.

temporarystress

ScottSecor said:

Just a shot in the dark here:
I'm guessing during a normal cycle the boiler water takes a long to return to the boiler. During this delay, the boiler starts to get low on water and calls for some water, automatic fill valve adds water and burner continues to operate. All is good for the moment. Then when the thermostat (outdoor reset control, etc) is satisfied, the condensate finally returns to the boiler. Unfortunately, the boiler is already full of water and begins to over fill. Every cycle may only add a quart or two, but after fifty or a hundred cycles the boiler is now flooded. We see this often with these types of mechanical feeders.

that^^^ is what i think is happening. this boiler is only 2 years old and we've had this problem since day 1 unfortunately. Our old boiler (Weil-McLain as well) did have no such issues. Thats why were thinking its the feeder or cut off.

clammy

I saw some welded piping on the header no steam union or companion flange that soon or later will crack that boiler in off season you should get that piping de done or wait and get a new boiler it s only a matter on time .did anyone check the install level for the combo feeder lwco .if set to high in trying to keep the water line at proper will always sooner or later flood .auto feeds are meant to maintain the boilers water level at the minimum required operating water level not at normal water level used to see installer doing it all the time and boiler-would end up flooding . You would be better off using a time delay on the feeder or a electronic lwco w a electronic feeder this way u can set some dips to delay to prevent flooding .just thinking Peace and good luck clammy