Low water cutoff question

quone17

Hi everyone, first time posting. Briefly my boiler has started semi-regularly turning off randomly, with the low water light flashing (sometimes sort of "weakly" flashing). The odd thing is that when I see the light on and the boiler is not functioning, there is clearly more than enough water visible in the sight gauge. As soon as I press the manual water feed button for literally one second, it will then pause and the boiler will turn on - sort of "realizing" that yes, it does have enough water and can safely run. I have tried emptying and refilling the tank multiple times to no avail, including trying to skim.

I have had a professional look at it but he did not see the subject issue happen first hand. He opines that we may need a new low water cutoff (roughly $1200) but he said something like, he sees water in the chimney indicating there is a leak so the boiler block may be failing, and suggests replacement. The boiler is 17 years old and he said it should last 25 so it seems it would be early for that expensive step. As a secondary question, I do not understand why if he sees water at the chimney it could mean you need a new boiler - the chimney starts like 6 feet to the side of the boiler, so wouldn't it be more that there could be a leak in a pipe or something?

Anyway, I was wondering your thoughts on chances that it is mainly the low water cutoff that is need of repair/replacement, vs. the need to replace the whole thing. Right now I am mainly concerned with how it randomly turns off, especially when we go away several days at a time. I did observe for the first time the other day that while the boiler was running, the low water cutoff "activated" and water was added to the tank - but I could still see that there was water a few inches above the bottom of the sight glass (again this is while it was running, the normal level is midway in the sight glass). Last comment - is there something I could do myself short of replacing the entire low water cutoff? (i.e. could there be something that's stuck or needs to be cleaned, instead of replacing the low water cutoff apparatus itself? I have intermediate to low skill level here.) Thanks so much for your help. I have been visiting the forum since last year when this first started happening.

pecmsg

sounds like a salesman more then a tech.
get a second opinion.

mattmia2

They should have cleaned the probe for the lwco and cleaned the sight glass to make sure both are clear in to the boiler. The test for a leak above the water line is to fill the boiler to the top with water and look for water leaking out so they seem to have failed on the basics of all of this.

TKPK

you should not be adding hardly any water…as mattmia said, overfill to the top of the sight glass and you will know.

sounds like you will have a problem though …

LWCO is a couple hundred for the electronic type and 600 for the float type for the part. $1200 seems awful rich

Jamie Hall

As the folks above have said (or implied) — first thing is to find a competent steam tech. and have hm or her check everything — and remove and clean the LWCO probe. Then see what happens.

That said, it does sound as though you may have a leak — but it doesn't have to be the boiler. "Water in the chimney" is a rather odd comment. One might see steam coming out of the chimney, but…

EBEBRATT-Ed

What @mattmia said "

"They should have cleaned the probe for the lwco and cleaned the sight glass to make sure both are clear in to the boiler. The test for a leak above the water line is to fill the boiler to the top with water and look for water leaking out so they seem to have failed on the basics of all of this."