When to replace an old steam boiler

steam33

I am wondering how to decide whether my snowman steamboiler ought to be replaced.(coal, converted to oil converted to gas) the system still runs and heats the home. I have conflicting information. On the one hand I have been told these systems can run "forever" on the other hand I have been told they rust out and that some replacement parts are virtually impossible to get. I have the system looked at each season, I use the system for supplemental heat as I have wood and small gas stoves in parts of the home. I have quote with removal and installation of a new system for approx. $9-$10K. It would be nice to run a new more efficient steam system and on the flip side part of me thinks the current system could keep chugging along for quite a while based on what I have been told. And while the fuel costs would be higher it seems it would be a decade or more before a new system would pay for itself. Any insights would be much appreciated.

lchmb

as is

the case with anything, it depends. It could last a long time, or it could quit January 1st when it's -10. In your case you have another source of heat, but my suggestion to you would be to replace it on your time not its. One other thing is asbestos. If that starts to break off the boiler it could be harmful to you and your family. I dont see anything at this point (hard to tell) but would suggest you get a pro in to remove it or at minimum inspect it for your safety. It's not nice stuff to play with.

Jamie Hall

If it ain't broke...

don't fix it.  It's sort of like an old car -- at what point do you trade it in?  Your fundamental analysis is correct -- that old Snowman is using a good bit of fuel more than a new boiler would.  You might be able to cut your fuel bill as much as 40% -- maybe even more; hard to say.  On the other hand, you note that you really use it more for supplemental than full time heat.



You are the only one who can say whether the cost of the money it would cost to replace it with a new one is more than the cost of the fuel used, and that is the figure you want to look at.



Until it does break down; they do run dang near forever, but sooner or later...

Tim McElwain

What do you have

for a gas conversion burner and how old is it?

steam33

rental burner

here is a photo - not sure if helpful or not

steam33

rental burner

here is a photo - not sure if helpful or not

ed wallace

when to replace an old steam boiler

are you renting the conversion burner from gas company? yes the old boiler coud last another 10 yrs but its inefficent do you still drive a 40 yr old car ?

Tim McElwain

That is an old atmospheric gas

conversion burner and it is very in efficient. I would look to replace the boiler very soon and rather than go with an atmospheric gas steam boiler I would go with oil and then convert it to gas with a gas power burner.



Steamhead can give you some information on that and some results on jobs he has converted and the overall efficiency gained by doing that type of changeover.

Steamhead

Well, so far

I haven't been able to do any direct efficiency comparisons between atmospheric steamers and wet-base power-burner ones in actual use- because all the atmospherics were rotted out when we replaced them, so they were using more gas than they should have!



But, going by manufacturers' published ratings, the thermal efficiency of a power-burner unit is roughly 6-7% better than an atmospheric.



Thermal efficiency is defined by what percentage a boiler's DOE output rating is of its Input rating. It is not the same as AFUE, but is equally important when selecting boilers.



For example, the Utica PEG-112 atmospheric steamer has an Input rating of 112,500 BTU per hour, and a DOE output of 90,000. Since 90,000 is 80% of 112,500, its thermal efficiency is 80%. Its Net rating is 281 square feet.



The smallest Smith 8 series boiler at its lower firing rate (the only approved firing rate with gas) has an Input rating of 105,000 BTUH and a DOE output of 91,000. So its thermal efficiency is 86.6%. It has a Net rating of 283 square feet. So with this one, you get a slightly greater output with a lesser input. Slant/Fin's Intrepid series boilers have similar thermal efficiencies. We would order one of these boilers without the oil burner, then order the gas burner designed for it. The ones in the pics are Carlin EZ-Gas burners, but Slant/Fin has approved the Midco EC series as well for the Intrepid.



It's easy to see why gas companies love atmospherics!