Returns a bit dirty......

adamfre

Good thing they are getting replaced. Check out the pic.

Steamhead

I'd say it's time.

nicholas bonham-carter

I wonder where all that solid deposit came from.
Was there constant makeup water bringing calcium into the system?
Certainly shows the importance of blowing down those returns.--NBC

gerry gill

Yup, like Steamhead said, its time for replacement. Good call on that.

adamfre

This system had been abused through lack of maintenance for quite a while. The fun part will be replacing the buried returns in the crawl. Not much room to dig them out, so I think I am going to try to use a borit tool to bore in the new pipe from the basement into the crawl, stay tuned to see how that turns out....

KC_Jones

If you are replacing them do you need to keep them buried?

adamfre

I need to keep the return beneath the waterline of the boiler, so yes. To compound the issue I have in floor radiators mounted beneath my floor joists, causing my "A dimension" to be pretty tight, preventing me from moving the waterline up by installing the boiler higher or creating a false water line.

nicholas bonham-carter

Why not make the new return dry, and then drop down to the floor as it exits the crawl space?--NBC

adamfre

@nicholas bonham-carter , I don't think I can, my system is an old two pipe air vent design, each return has to connect beneath the boilers water line..?? I think Dan has an illustration showing this on page 125 of his 'The Lost Art of Steam Heating' book.

JUGHNE

So would a new dry return work if traps were added at each rad...or even less money...... inlet orifices in each supply valve. Air vents on the dry return of course.
A dry return is a happy return and would make for an even happier pipefitter. IMO

nicholas bonham-carter

The orifices would keep the amount of steam down in the rad, so I thought the dry return solution would work.--NBC

The Steam Whisperer

Yep, If this is two pipe orifices make a lot of sense on nearly all old systems. They will allow you to adjust the radiation size down to the current heat loss, typically allowing you to install a much smaller boiler that runs much more regularly. This gives you a nice boost in efficiency.

Steamhead

This is "two-pipe air-vent", so the usual rules of two-pipe don't necessarily apply. Adamfre, the main difference between the two is that the usual two-pipe system vents air from the radiators into the dry return along with the condensate (water) and out a central air vent in the basement. On your system, which is an earlier design, the returns only handle condensate and the air is vented at the radiators.

Switching the system to the later two-pipe configuration might work if there is enough height between the boiler's waterline and the lowest point on the new dry return. You need at least 30 inches, more if you can get it. Then you'd orifice all the steam inlet valves, install a Vaporstat to keep the pressure low and you'd be good to go.

But the simplest way is just to replace the returns as they lie. I wouldn't bury them unless there's no other way, as when running past a door.

adamfre

Thanks for the info @Steamhead . The only reason I am considering burying the returns in the front of the house is because it's the only way I can keep them wet. (Half the house is over a basement, half over a 24" - 30" crawl) If I lay them out on the ground it will work fine in the basement, but will put 30' of return that goes out across the crawl space above the waterline. I don't think raising the waterline is an option because it will put the in floor radiators well within the 'A dimension'. Unless I am understanding this wrong, I'm doomed to trying the Borit tool, and a lot of digging

Attached is pics from the weekend, removing the old boiler.

JUGHNE

I have come very close to seeing a pipe or tool stuck into the open electrical panel. I always made a policy to keep the cover on panels. Pipefitters and plumbers are especially at risk.

adamfre

Good point @JUGHNE. The cover is on it now. In those shots I had not cut power over to it yet. Back in the day I had an experience with a power factor correction cabinet that 'welded' the importance of keeping cabinets closed and covers installed into my subconscious (and I'm lucky that's all it did)

JUGHNE

Those welding events are forever burned (sometimes literally)into your survival instincts.

Glad you got things covered!