Low Pressure Water Boiler Cleaning

Omega

I'm repairing/restoring a 50 year young residential oil fired boiler.  There is quite a bit of sediment, mineral deposits, sludge on the waterside.  It's a cast iron, vertical tube single pass heat exchanger.  I was planning to pump in TSP in solution, then  heat and soak in overnight.  The commercially available cleaners are just a bit too gentle.  Any thoughts?  Thankx.

clammy

50 year young?

at 50 years old i don,t think i would even think of trying to bottom clean a boiler of that age after bottom clean you may find the push nipples leaking being sediment  may be the only thing perventing it from leaking on another  note they have made leaps and bounds as far as  effeceny in steam boilers .I would if i where attemping to clean it remove the return piping and any water side plugs and drain  then using a cleaning brush  brush the water passes ,using a resourver style pump set up pump water through the boiler and keep on flushing till it came out pretty clean after afew repeat fill and drains i would reassemble and perform a skim on the boiler while firing the boiler a warm or hot skim is perferred .What manafactures boiler is it and can you post a picture of it that may help.Even afyter all the bottom water side cleaning it may lower your bill but i doubt as much as a newer boiler would ,i did have a HO who for years would always clean the water side himself and was very anal about it he had pasted and a reletive who ended up living if the house did not, later upon  the gas bill getting very high  i ended up replacing the boiler it had so much mud and was near impossible to drain i had taken about 20 gallons of total mud out of the boiler dumped in the back yard and hosed it away  the new boilers gas bill was about 1/3 of the older units ,just food for thought peace and good luck clammy