Posted by Evan Williams on October 01, 2001 at 11:34:04:
We have a one-pipe low pressure steam heating system in our home. On the return condensate line, one of the fittings started leaking, and we hired a local heating contractor to replace it. He did this repair with the same type and size fitting: 2" i.d., and then removed a plug on the top of the boiler, and poured in a cup (or two) of TSP cleaner. He said this was important to get 'the crud' out of the boiler. I have never done this, only draining the sludge every week during operating season. Anyway, he drained the boiler a few times (after filling, heating) and then left. The pipe is fine, however the water line now erratically goes up and down, eventually kicking in the low water cutoff. This goes on for about 15 min (a normal length for the heat cycle) when the burner shuts off the water line keeps climbing, and floods the boiler. The only other change the service man made was to install a new pilot, and clean the burners. I suspect it may be the ph of the water, but the problem could be overfiring. What do you think?