LWCO and probe removal issues

oz34

When I drain the broiler while is it off the LWCO works as it should, but while it's on it does not initiate until the water in the sight glass is almost gone. I bought an updated LWCO and used it with the existing probe and it is still doing the same thing. I want to replace the probe but I am having difficulties taking it off. I don't want to use too much force and possibly damage something, can that be a possibility?

Jamie Hall

What's the matter with it not initiating until the water in the sight glass is almost gone? Somewhere on the boiler near the sight glass there should be a line or a label, indicating the minimum safe water level for the boiler -- which is where the LWCO should cut off. On most (but not all) boilers this will be around an inch or so from the bottom of the sight glass.

Sounds to me as though it may be doing exactly what it is supposed to do.

oz34

The red light goes off about half an inch from the bottom to the water almost unseen. The minimum safe water level is a half inch according to the sticker on the boiler. I also get water hammer coming from the boiler when the LWCO shuts off the boiler and starts the filling process. Is this normal? I had a tech examine the boiler and he said 'that is normal'.

KC_Jones

How often are you hitting the low water? How often do you check on the boiler? Honestly you should be adding water long before you hit low water and it shouldn't happen too often.

oz34

I add water every time I am at home before it reaches that low, which is for the most part in the morning before going to work. The water hammering is what has me worried. It does happen about 3 or 4 times a cycle - if I am explaining it correctly. BTW, I have a single pipe system.

KC_Jones

If you are adding water daily that should be a concern. How much are you adding daily?

Water hammer is from water laying in a pipe or radiator being picked up by steam and slamming the water into something that won't move, pipe elbow, end of radiator etc.

Jamie Hall

When the water in the boiler gets that low -- while still safe -- I'm thinking it uncovers the Hartford Loop, which will hammer.

You should keep the water at about half way to two thirds up the glass.

If you are adding water daily to keep it even close to that, you are losing way too much water, and have a significant leak somewhere.

EBEBRATT-Ed

I agree with @Jamie Hall & @KC_Jones . It sounds like your adding a lot of water. You should look for leaks, Do you have any return lines under the basement floor? Check your chimney for white smoke when the boiler is running. The boiler could have an internal leak...hopefully not.

Also, your boiler is safe to run as long as you can see the water level in the glass but should be half full normally.

Because the water level in the boiler is probably bouncing slightly the level in the gage glass and the level at the LWCO probe may not exactly agree. As long as the LWCO works and works reliably I wouldn't be concerned.

As far as the hammering as Jamie mentioned the hartford loop usually 2-4" below the normal water line may hammer if the water level is low.

Why not post a few pictures of the boiler and piping?

I think the answer is to find your leaks and maintain the water level at 1/2 a glass

oz34

Here go a few pics. I have a replacement probe but I am having a hard time loosening the present probe in the boiler. I don't want to use too much force because I fear that I may crack the boiler some how where the threads are. Can that be a possibility? I was thinking of calling a pro and having them do it instead.

When I drain the boiler when it is off the lwco immediately comes on if the water drops a little bit below the probe. But when I do the same when the boiler is on the lwco does not come on until the water is almost gone.

Gordo

@oz34 : I'd get a 1/2" drive 1-3/8" deep socket (and a 1/2" drive breaking bar). That should fit on that McD/Miller probe and help you get good torque on that thing. Make sure those #8-32 mounting screws are ALL the way in before you wrench on that probe!

oz34

@Gordo thanks for the info! Before removing the probe should I warm up the boiler or it doesn't matter?

Fred

It doesn't matter. Just be sure to drop the water level to below the probe.

Lance

Remember pressures change everything. Beware the restricted return causing a longer delay than these new LWCO may be timed for to prevent flooding.