Replace or Rebuild or Convert

show number three the door

have number one and number two measure the EDR?
If not you can throw them out also.

250,000 BTU/h, 630 EDR is huge

Don't switch to hot water so take that off the list.

Obviously the water has been leaking down on to the burners and rusted them up. Weather the boiler can be fixed is something difficult to tell from here. Weil Mclain makes good boilers so there is that and that boiler is still made.

That is a large boiler 250, 000 btus

The first thing to do because a lot of boilers installed in the past are oversized (this isn't a good thing; more is not better) is to measure all of the radiators and determine the EDR capacity. This will point you to the correct boiler size. We can help with that. We need height, length and width and some pictures.

This may seem like nonsense if your old boiler did the job, but trust me it is important.

We also can't talk price on this forum so there is that.

Once you have the total EDR load we can pick the boiler.

The most important thing is the correct contractor that knows steam. He has to pipe the boiler in accordance with the instruction manual and skim the water when he is done. Again, I can't stress this enough. Some contractors are hacks (sad to say) and will not follow the instructions.

Don't become a 'Heating HelpHorror Story"

converting to hot water is a terrible idea. fix the steam problems. hot water is a lot more pressure and weight on the piping and you may find leaks in pipes or radiators you don't have at the .5 psig or so the steam is at.

how old is the boiler? a rebuild is likely only a good idea in a small boiler if it is pretty new and it is because of gasket failures. you spend the labor to take it apart and put it back together then a section rust out and you have to do it again or replace the boiler anyhow.

@Stardance where in the Midwest are you located? We might know someone……………….

That looks like a standard type of Vapor system. Vapor is ultra-low-pressure 2-pipe steam, and was the Cadillac of heating in its day. It's still one of the best systems out there.

The trap on the bathroom radiator looks original, and might be a Webster 02H. The others look like Hoffman 17C units.

Are there any cast-iron devices in the piping around the boiler? Any traps at the ends of the steam mains?

Hard to tell, from here. @Stardance , are there any names on those valves?

It may have short cycled. Maybe not. Steam system boilers are sized on EDR, NOT on building heat loss. How many times do we need to say that? If the boiler is properly sized with regard to the radiation, it will not short cycle.

Improvements in building envelope will reduce the number of times it needs to run in a day, and possibly the length of each run — thus saving fuel as expected. But they WON'T alter the timings within any given run.

It does look as though it may be a vapour (low pressure) system, in which case a useful addition to the new boiler will be a vapourstat pressure control, rather than the standard pressurestat.

I don't have a copy of Every Darn Radiator — but someone does, and with the info. and pictures someone can add up the EDR for you, @Stardance and check your boiler size. At a very rough guess, just looking at the radiators withuot the book, I'm going to say somewhere around 400 square feet, so the existing boiler may be one size too large.

I am not an expert but corrosion pattern matches condensation dripping from outer, colder, parts of the heat exchanger. Looking at boiler's specs, the steam Mbh is 177 which is oversized for 1200sqft home. Even if radiators match boilers steam sq ft the boiler will be short cycled by they thermostat.

Got it, makes sense. It's terribly inefficient but does not cause environment for flue condensation since heating only happens when water is turned into steam. That corrosion got me fooled.