prestige lp issues what would JC do

clammy

Just wondering what others would do .Was called to look at a prestige 250 that was installed about 3 or 4 years ago has some noise issues when running it was a barter job and i did not do it nor had any thing to do with it .Well to start off the piping was not up to snuff in my book reduced at the boiler from 1 1/4 to 1 inch and sort of ps piped but way short of the mark aside from only a 3/4 gas line and the LP  regulator about 8 ft away the inlet pressure was 11 w c and drop to about 9.5 when running .I really could not get a combustion reading due to the fact that the boiler would not run long enough 1 or 2 minutes and it would cyle off .It started off and ran fine with the outdoor reset wired in .I disconneted the sensor so it would run longer but it did not help and the burner then started to backfire upon start up .I re conneted the out door sensor and the start up rummbling stopped .I still did not get a combustion reading off of it .The boiler was piped as the primary loop  with the seondary being the system except the installer did not follow proper P/S distanes on the tees and jammed a st ell into the return tee of the secondary loop so the flow into and through the secondary loop is crap with a huge temperture drop .The HO has asked what i could do i suggested to repipe it corret the gas piping and flue piping which also a far from the manafactures specs but when all is done the boiler is still way over sized .The home is about 2400 sq ft with about 130 ft of slant fin 30 .Am i way off base in thinking of tossing this boiler and just put in a properly sized cast iron direct vent boiler.I already know that the baseboard was not over sized so in my book it would only be early and late season where it might condense and maybe te modulation might help but i feel it ain't gonna justify the cost .Last year he burner 1800 gallons of LP .He has had the installer and the  local rep they all say it is normal and its running fine i say it is BS at close to 90 btu sq ft they are cta.Also upon first starting there is alot of noise like boiler water is boiling and the boiler very quickly ramps down then a minute later the burner cyles off .The guy installed a taco 0010 as the boiler pump and of course the installation and operation books where not there .Thanks for any input peace and good luck clammy