steam upstairs, hot water loop down...

bic

My new (but actually old) house has a one pipe steam system that heats the first and second floors. Some time ago (long before I owned it) someone re-finished the basement. They did 3 things relevant to this question:

1) pushed all the utilities into one corner of the basement and closed it in as a tiny utility room with a few doors separating it from the finished area

2) installed a hot water loop off the boiler and ran baseboard heat in the basement (with its own thermostat).

3) removed the wall on the stairs going down into the basement to open things up (which makes it pretty easy for hot and cold air to exchange between the basement and the rest of the house)



I quickly noticed that when the boiler is running there is enough waste heat that if I leave the utility room doors open, the basement gets plenty warm. (it's a pretty small house - the basement is only ~16'x16'.) since we hadn't been using the basement much, I didn't mind leaving the doors open and figured it was better to circulate that heat than to waste it. i never really used the baseboard and just left the thermostat all the way down. this has been working quite well for me -- the house is nice and warm and there aren't particularly bad hot and cold spots.



i finally organized the basement the other day and in doing that closed up the doors to the utility area before i went to bed. woke up that morning and the upstairs was unbearably hot. Walked down to the first floor and it was noticeably cooler with the thermostat calling for heat and the boiler firing away. walked down to the basement and it was downright cold. this was with the basement loop turned off.



clearly not heating the basement was messing up the heat for the whole house. so here are my questions (sorry for the lengthy intro):

1) is it 'better' to leave the door open and bleed heat off the boiler or to run the hot water loop. i guess you can define better in different ways. more efficient? more pleasant?

2) how am i supposed to control this system? the basement loop has its own thermostat, but when it calls for heat, the upstairs radiators get hot too because the boiler is firing. that's not ideal. my guess is that maybe i want the main thermostat to just turn on the basement loop as well so that the whole house is heating together, but I wonder if that's wasteful.



thoughts?

thanks.

JStar

Steam

I would bet money that the circulator loop is not installed correctly. It should have a control to shut the boiler off before it makes steam. I would guess that the circulator is a TACO 007 that is currently not working.

bic2

yup!

you've done this before...



so yeah - there's a TACO 007-F5 pumping water from the boiler to the heat exchanger. but there' also a TACO 007-F4-7 on the return of the loop, just before it feeds back in to the exchanger.



So how do I tell if it's set up correctly or broken, or both?



Thanks.

(sorry, I had to re-register with a new name -- my old account wouldn't work and I couldn't get a forgotten pwd email...)

bic2

i think i see...

looking around on this site i see that there should be a thermostat that shuts down the boiler when the circulating water reaches a certain temperature? presumably this keeps the boiler from actually sending steam up to the radiators, like you said?



I'm a total novice -- can someone send me a pic of what this thing is supposed to look like so I can see if I have one? Or maybe give some other description of what my system should look like if things are set up correctly?



much appreciated.

SamanthaSlater

Oh my gosh!! This is almost my exact problem. We have a Weil Mclain steam boiler that makes steam for the 2nd floor radiators and hot water for the first floor baseboards. Last winter, it was always incredibly hot upstairs because the steam was always on due to the first floor needing hot water for its system. It seems like a ridiculous set up, but I'm getting from the response to this post that it's not supposed to be like that. Is that true? Should the first floor be able to heat properly without the steam radiators on full blast? They come on even when we have the thermostat turned very low, if we're trying to heat the first floor. Any advice would be appreciated--it was incredibly expensive to heat like this last winter.

Steamhead

We've done a few of these. Here's a thread in which the hot-water loop feeds an indirect hot-water tank, but the setup for feeding baseboard is the same. You have to click on the pics to see them, since this carried over from the old Wall.

http://forum.heatinghelp.com/discussion/132567/one-of-the-worst-maintained-oil-fired-boilers-weve-seen#latest

The circulator should always be a bronze 3-piece, oil-lubed one.

bic2

sorry steamhead -- i don't think I see the part of the thread you're talking about on that link?

SamanthaSlater, in the intervening year I've figure it out a little, (but not fixed it) so I can try and tell you what I learned. I think our systems might be pretty different, but the way my system is *supposed* to work is that when the basement calls for heat the boiler will kick on and a pump pulls hot water out of the boiler and into a heat exchanger. A second pump then circulates the hot water loop (baseboard) through that exchanger and around the basement. My problem is that it will do this until the thermostat is satisfied, so eventually the boiler gets hot enough to start making steam and things get hot upstairs even if that thermostat is off. I know that there's an aquastat on the heat exchanger that's supposed to regulate this process, so I assume that's my problem and maybe yours. The hot water is supposed to turn off at some temperature below 200 so you don't make steam when all you want is hot water. I also think it's supposed to keep you from running boiling water through your hot water loop, which is probably also not ideal.

So, I think I get the very broad strokes of how it's supposed to go, but how to figure out what's wrong, and how to fix it, are a total mystery to me at this point -- but i'm looking for help!

actually, if anyone could link to a post that described the theoretical control setup of a system like this (loops, pumps, controls, etc) that would be fantastic.

Steamhead

Look at the posts that start with "After the gas line repair was done" and "SuperStor is done" and you'll see how the aquastat is mounted in the boiler so it reaches into the boiler section to measure the water temp there. This is what keeps the boiler from steaming when only the indirect is calling.

bic2

Thanks.
Yeah, that is DEFINITELY not what I have on my system. The aquastat is on the body of the heat exchanger, which I guess might be sensible but I don't know. I can't tell whether its testing the heat of the boiler water or the loop.

I'd posted this in the radiant heat forum last year as well and so i've now got dueling response threads going (sorry). i posted a pic over there, so here's the link.
http://forum.heatinghelp.com/discussion/148373/is-my-hot-water-loop-wrong#latest