Steam heater: adding water

December 23, 2010 7:21 PM

Steam heating system in an old house. Do I add water, and where?

Hey guys, we just bought a 1921 four square house. Brick, 2,144-square feet. The entire house is heated by a steam system. Below are photos of the unit. I've never used one of these before, but I understand water must be added manually on some. The seller mentioned however, that this one runs off of a water line in the house. The water is off at the moment pending some plumbing work in early January. Since I can't tell if the water must be on to operate this heating system, we've had the heat off, too. That's not ideal here in Ohio in Winter, we have space heaters all over the place to keep the house warm. Anyway, do I add water manually, and where? How much? Or is this truly connected to a water pipe? I can't tell! The seller assumed it was connected to the water line, but she's an elderly lady that didn't give me the impression that she knows much about the mechanics of the house.

Here are photos:
photo 1
photo 2
photo 3
photo 4
photo 5
photo 6
photo 7
photo 8
photo 9
photo 10
photo 11
photo 12

posted by Salvatorparadise to Home & Garden (12 answers total)

I believe that red doodad is an automatic fill valve. I would say the water does need to be on for the unit to operate correctly. But it depends on how much water (vapor) the system gives up. In a perfect world, all the water recirculates and it rarely needs make up water. But I don't know. This really is a job for a HVAC/plumbing person. They can also tell you how the thing works. It would be a good investment.
posted by gjc at 7:27 PM on December 23, 2010

Response by poster: gjc, i'm thinking i'll probably have the guy come and check it over, and give me some pointers on how to run the thing. It's really old and nasty, but we'd like it to hold out for a few more years.
posted by Salvatorparadise at 7:29 PM on December 23, 2010

Maybe read this.
http://www.oldhouseweb.com/how-to-advice/hvac-steam-heating-systems.shtml
posted by JayRwv at 7:56 PM on December 23, 2010

I think it's a hot water heater. The bigger red thing is the circulating pump that sends the hot water through the house. It's a sealed system, connected to your water supply by the smaller red intake valve and it does need to be full of water (bled of air) to work properly. You'll need the water on.
posted by lee at 8:25 PM on December 23, 2010

I'm with lee, I think it's a hot water system, not steam. How many pipes go to each radiator? If it's one, then it's steam. Two and it's hot water.
posted by octothorpe at 8:47 PM on December 23, 2010

If you have steam heat, then yeah, there needs to be water in the system to sit in your boiler, turn into steam, and be sent to your radiators to heat your house. This water needs to be occasionally replenished due to loss, which means new water needs to come in from a pipe somewhere.

If you need to add water manually to your system, then somewhere on the furnace there'll be a little indicator showing you the current water level so you know when you have to add more. On mine, which is the oldest furnace in the universe, there's a little vertical glass tube called the "sight glass" that's (ideally) about half full. When it gets too much lower than that it's time to open the shutoff valve on the water pipe leading to the furnace and add water until the sight glass is about half full again. If you don't have any kind of water level indicator, then it's likely that you have an automatic fill valve and you don't have to do anything yourself. I can't tell what that corroded ol' gauge in your picture is for, but if I had to guess it's probably a pressure meter and not a water level meter. Your furnace is relatively new so it probably has an autofill valve.

You should be able to provide water to the furnace but still keep the water off for the rest of the house. You've shut off the water to the entire house, so you've obviously found the pipe that supplies water to your house. Follow that pipe and see where it leads. Close the shutoff valves for all pipes not leading to your furnace, then re-open the main valve. Water will go to your furnace but nowhere else in the house.
posted by xbonesgt at 8:48 PM on December 23, 2010

Response by poster: i think you guys are right, that it's hot water. that big red thing is a pump, i remember now the seller telling me that it was replaced fairly recently.
posted by Salvatorparadise at 8:58 PM on December 23, 2010

Response by poster: woah, this is good:

it explains it all!
posted by Salvatorparadise at 9:00 PM on December 23, 2010

I recommend that you get a copy of The Virgin Homeowner. It covers every system in a house (roof, heating, cooling, plumbing, electrical, etc), what you're likely to encounter, what you're likely to see, how it works, what maintenance you need to do and when, when to replace, etc.

It has been an invaluable tool in out built-in-1840 house.
posted by plinth at 3:49 AM on December 24, 2010

I'm going to suggest that you don't have "steam" heat, but hot water heat, you probably have baseboard heating units along the wall.

That boiler isn't so old that you should be worried about it. The boiler in a house I bought in the early '70's lasted until the late 90's, and was still running when I sold the house. They're pretty foolproof. If the pump, the major moving part, has been replaced, you might be good for a while with only minor repairs (thermocouplers, valves, and such).

As for the "does the water need to be on" to run the boiler, unless you get a heating/ac person showing up in that thread, i would make a call to a local heating company and ask that question. My suspicion is that, for a while, that would be fine, but if the boiler is calling for water and doesn't get it, eventually you'll probably see it shut down.
posted by HuronBob at 4:35 AM on December 24, 2010

I meant the little red thing, in photo 5, fwiw. The water supply is on the right, the hot water return is on the left. It (I believe) is a pressure regulator. If the water pressure inside the system drops, it lets more water in.

If it IS hot water, and not steam, you can probably run it more or less safely. Provided you turn off the valve between the system and the water supply. If it starts gurgling, shut it down.
posted by gjc at 5:37 AM on December 24, 2010

Yep, hot water (not steam) heat. The red thing with the bell is a pressure-reducing valve. Some of your wide-angle shots show the water heater on the left, and it looks like there's a line that runs across, with a tee that drops down to the PRV. Used to be, there would be a manual fill and a tank in between the floor joists above.

You're going to need to bleed the system, I'd posit. Get an HVAC guy - one that has experience on boilers, perhaps the company who put their sticker somewhere on the boiler, if they're still around - to check the thing out, and show you how to bleed the radiators, and what order to bleed them.
posted by notsnot at 7:18 AM on December 24, 2010