To get email notification when someone adds to a thread you're following, click on the star in the thread's header and it will turn yellow; click again to turn it off. To edit your profile, click on the gear.
The Wall has a powerful search engine that will go all the way back to 2002. Use "quotation marks" around multiple-word searches. RIGHT-CLICK on the results and choose Open Link In New Window so you'll be able to get back to your results. Happy searching!
In fairness to all, we don't discuss pricing on the Wall. Thanks for your cooperation.
Need to contact us? Visit

water level in steam boiler keeps droppping and triggering LWCO

I have a fairly old--35yo--boiler which has been doing fine until recently.  I noticed today that the thermostat would kick the boiler on, it would run for a couple of minutes, then the water in the site glass would drop to empty and the LWCO would kick in and shut the system off.  The site glass would then show water coming back in which would result in the system kicking back on only for the same thing to happen again.  This occurs repeatedly.  We recently had the boiler serviced due to a dirty site glass which included a chemical treatment.  This issue developed shortly after that.  We did notice that the basement where the boiler is located was very warm the day immediately following the service.  It seems to me that the water is being pushed back into the return line as the pressure rises in the boiler reducing he level and triggering the shut off but I haven't the faintest idea why.  I have the company with whom we have a service contract and who did the prior service come out shortly.  Any suggestions or thoughts as to the cause?




  • [Deleted User][Deleted User] Member Posts: 2
    bad response to chemical

    heating guy says it is a bad reaction with the chemical that was put in which was causing the water to surge.  It was amazing to watch--the site glass went from showing the proper level to being empty in 10 seconds.  What would cause this to happen?
  • SteveSteve Member Posts: 234
    Water surging

    is a likely culprit. You should do a thorough skimming of your boiler to get all the chemicals and oils out of the system. Your boiler will be much happier. Just an FYI there could be other problems going on. Post pics from different angles of your boiler and some pros here might be able to give you some additional advice.
This discussion has been closed.


It looks like you're new here. If you want to get involved, click one of these buttons!