water level in steam boiler keeps droppping and triggering LWCO

NickG

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?

Thanks,

Nick

NickG

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?

Steve_175

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.



http://www.heatinghelp.com/forum-thread/135204/Will-skimming-fix-classic-steam-heating-problems-new-gas-boiler