Boiler keeps over filling

BillAllen

I have a W/M Gas 5 section steam installed an auto feeder but the system keeps overfeeding and over flowing through the radiators. I set the dip switches to "3" lowest amount water 30 seconds. Still water over feeding.
No leaks anywhere air vents good. Pipes banging from too much cool water sitting/feeding.

The return water seems to be coming back ok. Maybe the pressuretrol which I did not check yet. I'm crazy trying to figure this out!

Bill

KC_Jones

What does the water level in the sight glass look like while the boiler is running? It should have a very slight bounce roughly 1/2"-3/4". If it's more than that you could be surging causing the feeder to feed then when the water returns it's over filled. The feeder should only feed for a low water situation which should rarely if ever happen. Many people don't even install them.

Abracadabra

manual feed valve leaking?

BillAllen

Manual feed valve NOT leaking. There is a slight bounce in the site glass nothing crazy.

KC_Jones

Have you watched the boiler while firing to see when it is feeding? It should only feed on low water. If it is feeding at any other time then it could be a bad feeder or LWCO or a problem with the wiring/controls. With everything running correctly it shouldn't ever go into a low water situation during normal operation. And even if it did it should take a long time to get there a month or even longer (depending on how much water you manually remove blowdown etc.).

nicholas bonham-carter

Leave the valve in front of the auto-feed closed, and see how the waterline behaves. My guess is that the water is getting hung up somewhere in the piping, and will retun after shutdown.
Look for a return pipe somewhere close to the waterline height, but above, where it could hide.--NBC

Fred

I'm guessing you have a probe type Low Water Cut-Off. Make sure the probe that goes inside the boiler Block is cleaned sing steel wool and sure the probe is not mounted using any teflon tape as that won't allow the probe to ground itself.

BillAllen

New LWCO installed 3 weeks ago

Fred

BillAllen said:

New LWCO installed 3 weeks ago

Did they install it with teflon tape on the fitting that mounts into the boiler tapping?

vaporvac

Is your DHW attached to your boiler or do you have a separate WH? If the former, it could be leaking. However, since this results in an overfill, I' guessing it's one of the above suggestions. Did this just start with the new LWCO or is it why you replaced it in the first place?

Jamie Hall

Test 1. Close the valve to the water feeder. Observe the water level through a complete firing cycle. It should not drop more than an inch or two while firing, and then come back to where it started.

Test 2. (If this is your only LWCO). While the boiler is firing, deliberately drop the water level. The boiler should shut down when the water level reaches the probe. If it does, refill the boiler manually to the normal level.

Ir it doesn't, and this is the only LWCO, you have a very dangerous situation. Turn the boiler off and leave it off. If you have no alternative, turn it on if and only if someone is there who will watch the water level at all times while it is firing. No potty breaks.

Assuming that Test 2 passes, leave the auto feeder off for a day or two, and keep track of the water level. It should neither go up nor down much.

If it goes up, you have a leaky manual valve. If it goes down, you have a leak somewhere in the system.

A few days later -- turn the autofeeder back on. If it starts misbehaving gain, the problem is in the feeder -- since it is new, you should be able to get the installer to figure it out and fix it.