Thermostat Placement to Balance Steam

coachgvaz

I have a 3 family home with one furnace (one pipe system). Thermostat is located on the first floor. The second and third floor heat well when there is an increase of 2-4 degrees on the thermostat. During the weekends the thermostat setting remains the same as most tenants are home. The second and third floor do not remain as warm as the first floor. Also, during overnights, the second and third floor temperatures are well below the thermostat setting. I've been recommended to relocate the thermostat to the second floor. Is that a smart decision?

KC_Jones

With steam that most likely won't change anything. For example, let's say you have it set for 70 on the first floor now, the second floor is 68 and the third is 66. If you move it to second floor and set for 70 the first floor will probably be 72 and the third floor will be 68.

You have a temperature differential problem which will be a venting/balancing issue.

I see on your other post you are looking for venting help, EzzyT is very good with steam contact him and see what he can do.

HVACNUT

Can you provide some info on the boiler and post some pics from 10 ft away?
Main vents ok?
Rad vents ok?
What's the pressurtrol setting?

nicholas bonham-carter

I suspect the colder areas are getting steam later than some others, because of a lack of main venting, so check that first, if needed some of the top floor apartments may need faster vents.
Generally it is best to use large capacity venting on the mains, and slower vents on the rads.
In my 3-floor, 55 rad building, I have the remote sensor in the north most bedroom, so it feels any drops in temperature quickly.
I do not use temperature setbacks, and therefore feel the setting can be lower than it would be with them.—NBC

coachgvaz

on the 1st floor, where the Thermostat is, the air valve is a No. C. From what I've researched it should be a No. 4. Two other rooms on the first floor have a No. 6. Perhaps they should have a No. 5. If correcting the valve sizes on the first floor- will that help get heat to the 2nd & 3rd floors when the thermostat calls for a maintain of temperature? Again, with 2-4 degree increases all floors heat. Same temperature during the day or low temperature overnight those floors get nothing.

gfrbrookline

That would likely help, 6's and C's should only be used on large rad's and ones furthest from the boiler.

coachgvaz

@HVACNUT

I attached pics.

There are 3 air valves by the boiler. They are all No.1 Air Eliminator. It seems like one is missing.

The boiler is a 1987 Weil McLain. 300,000 BTU input.

It has an automatic feed, Low water cutoff, and high pressure limit switch

EzzyT

You don’t have just a balancing issue you have a near boiler piping issues too.
That boiler is most likely oversized and the near boiler piping need to be addressed along with the main venting and radiator vents.
Placement of thermostat would be the last thing I’d worry about.

EzzyT

Oh can’t forget about insulation on piping.

gfrbrookline

Is it worth it to try to correct NBP on a 30 year old boiler?

EzzyT

I have in the past, luckily those boilers where in great shape, but still I wouldn’t recommend it. Just replace the boiler along with the near boiler piping upgradamd balance the main venting and the radiator vents.

neilc

guessing here, but, that Ptrol is dialed all the way up,
how much says the pigtail is clogged ?
Do you ever see that gage move ?

coachgvaz

I have 16 rads to heat up. The boiler works great when the thermostat calls for heat. I've been told by many contractors that the boiler is the correct size for this building. The problem is that when the thermostat calls for heat to maintain not increase the heat doesn't get all the way. It just satisfies the first floor

coachgvaz

I can't recall seeing the dial move. What should it be set at?

Dave0176

coachgvaz said:

I have 16 rads to heat up. The boiler works great when the thermostat calls for heat. I've been told by many contractors that the boiler is the correct size for this building. The problem is that when the thermostat calls for heat to maintain not increase the heat doesn't get all the way. It just satisfies the first floor

That would be a venting issue.

neilc

but none of those contractors recognize the inferior piping at the boiler, nor the pressure setting,
and if you do get heat to the third floor the windows will be open on the first.
does the gage move ?

neilc

tough love, sorry.
Ezzy is some of the best contractors here,
I know a little,
this place can help you help yourself,
but ya gotta play along.
there are books here for sale,
We Got Steam,
https://heatinghelp.com/store/detail/we-got-steam-heat
buy it and read it

coachgvaz

@neilc
I don't recall the gage moving. I would have to look when the heat cranks up. What should the Pressure dial be set at?

neilc

the Ptrol should be set to it's lowest,
but,
watch a boiler run first,
if the gage doesn't move, then as I wrote before, i think your pigtail will be clogged and need cleaning.
If you dial the Ptrol down and the pigtail is clogged then the boiler may not come back on.
The pigtail is the looped pipe under the Ptrol (pressure setting device) and the gage on the Tee.
See if the gage moves.
And if the boiler is building pressure higher than say 5 #, the vents may be locked up and not allowing air out(no steam in), and no heat upstairs
Ideally, the boiler runs below 2 #.

KC_Jones

EzzyT said:

You don’t have just a balancing issue you have a near boiler piping issues too.

That boiler is most likely oversized and the near boiler piping need to be addressed along with the main venting and radiator vents.

Placement of thermostat would be the last thing I’d worry about.

This would probably be one of the greatest understatements I have ever seen on this site. Referring to this as issues, would be like saying it gets breezy during a CAT 5 hurricane. It's like the installer was blind.

The pressure is probably that high because that single pipe coming out is not allowing much steam out. The boiler probably builds pressure as soon as steam comes up.

To the OP, if no one has recognized the problems with that piping, please don't ever invite them back to look at your system. It's not even remotely close to right.

I agree the thermostat is literally the last thing I would even think about.

If you aren't going to repipe or replace that boiler and want to try and balance it, you need to start with the length and size of the mains, then we could recommend how much main venting you need. That's where this starts.

I should mention that if you get an actual steam pro in there to either replace or re-pipe the boiler, you will most likely have to re-balance the system due to the dramatic change in system performance. That's not to mention the most likely dramatic fuel savings you would see with proper piping.

neilc said:

tough love, sorry.

^^^^that.

neilc

post a pic of the glass water gage head on,
Is that water dirty?

coachgvaz

Yes, the glass has got some sediment in there

neilc

another guess on the pigtail being dirty,

the pressure gage "could" be broken,
but you should be able to see it move some,
especially with the Ptrol turned up that high.

gfrbrookline

You didn't post any pics of the front of your boiler but I think I saw the back of a gray box in one. If that is your pressurtrol set the front to .5 and the inside dial to 1.

Your boiler is not running great if it runs but does not make enough steam the heat the rads. If your Ptrol is not set to the above settings like others have said you have a venting problem with the mains and a balancing issue since you are way over venting the first floor which is robbing steam before it can go to the upper floors.

First vent your mains properly those G1's are likely way to small, what are the length and diameter of your mains? You may want to add vents to the top of your risers as well.

Once you have the main vents corrected you can address the rads. The first floor should have 4's and 5's on the larger rads, The second should be similar may need 5's and 6's for the third. If you have radiators that are much larger than others they will need larger vents, ie 4 column radiator is fine with a 4, 5-6 column with a 5 and so on but may need to be increased based on distance from the boiler.

Jamie Hall

To go back to a question which was raised earlier. Yes, if you slow the radiators on the first floor near the thermostat down -- a lot -- then they won't heat as fast and the boiler will run longer, which will get more steam and more warmth upstairs. This is the essence of balancing the system.

However.

Until the pressure is down where it belongs, and you make sure the mains are vented adequately, doing that won't help much -- so start there.

Those are simple and inexpensive things which you, @coachgvaz , can do yourself, and will make a big difference.

The problems with the near boiler piping -- which is certainly a good long way from ideal -- can be left until later. First things first here.

SuperJ

I'm no steam expert, but I've had good experience with adding wireless remote sensors to the ecobee thermostat. You can even schedule when the stat should look at each sensor.

I'm not saying the stat is the problem or changing it will help, but
I have had some office spaces where the stat was put in the interior of the building and wouldn't start the heat until the perimeter zones were freezing. Putting some wireless sensors in closer to the perimeter (in the corner boardroom), made the heat cycle more/longer and resulted in much more even temperatures.

Also, others would have to comment on whether an Ecobee is appropriate for use on a steam system.

nicholas bonham-carter

I had problems with going wireless, due to our heavy masonry, and stone construction weakening the signal, and the large power draw of the base station overloading the boiler transformer, so I went with the Honeywell VisionPro wired sensor in the most exposed room in the house-7 apartments, 55 rads.
If only they had a connection such as the old Radio Shack plug and talk intercoms, this would not be a problem.—NBC

coachgvaz

@neilc
Thermostat called for a 4 degree increase this morning at 6:00am. The boiler kicked on around 4:50am. I went downstairs to check the pressure gage around 5:45am. It was at 10psi. It may have been higher if I went down earlier. So yes, the gage moved

Neild5

If you are running at 10 psi you are burning too much fuel to heat your house. The pressurtrol needs to be turned down to save energy. After an hour of running the vents should have closed on steam so the problem is the near boiler piping.
I live in a 20 unit condo building and on a 0-3 psi gauge it never gets up to 1/2 psi.

neilc

ok, so that should mean the pigtail is not clogged, though at some point you would want to check it just to be sure.
I'm assuming the boiler shuts of at 10#,
The gage should drop back down and the boiler cycle back on, this may be a psi or 2, depending on the cut in dial inside the Ptrol.

However, the 10 is bad, way too high, and likely has damaged vents, both the mains and at the rads,
Dial the Ptrol down to the bottom of the scale.
try for ~ 0.5 on the front scale, the screw on top to the left does this, don't go past when you feel a slight resistance.
Inside there is a white dial, set that to 1. Caution, live wires inside, you can shut the boiler off for safety while under that cover.
Next, let's fire the boiler and see that the mains are working, they should pass air, then seal shut to steam, you can use a tissue or "carefully", your hand, to feel for air.
You will want to add a vent where that 90 is plugged.
Match existing if they still work, or upgrade them all to Bigmouths, https://heatinghelp.com/store/category/vents
After you confirm main venting working, move up to the rads, fix or replace the cold ones first, same for same, and then we can think about getting into balancing.
post pictures where you have questions.

Fred

10PSI on a residential boiler is crazy. Something is wrong. Either the pigtail is clogged, the tapping that the pig tail is mounted on is clogged, the Pressuretrol has failed or the Pressuretrol is mounted below the boiler water level or the gauge is not reading correctly.

neilc

or his previous "technicians" had spun up the Ptrol,
he's here now.

coelcanth

sounds like you have a number of issues here, but i thought i might point out there is another factor that rarely gets mentioned but might help to balance out your system;
that is the anticipator setting on your thermostat (if you have)

on my system with old round honeywell thermostat, i noticed that the floor with the thermostat control would not heat as well as the other floor.. in fact, sometimes the boiler was shutting down before steam even reached the end of the main for that floor..
how could the thermostat have been satisfied if the room didn't even have steam ? i wondered...

it was not the pressuretrol that was causing the boiler to short cycle, but the anticipator inside the thermostat was set way too low and shutting down the boiler early. raising this setting (fewer but longer boiler cycles) went a long way towards allowing steam to fill the radiators on both floors and evening out the heat

coachgvaz

PSI is set correct now. The issue is the boiler short cycles when it maintains the temp on the thermostat or overnight when the thermostat is set low but not on a temperature increase on the thermostat. Also, i have the wrong size air valves in a few spots on the first floor, particularly where the thermostat is located, a venting issue on the main line and undersized piping near the boiler. If the boiler doesn't short cycle all floors gets heat.

KC_Jones

It probably won't work well with low pressure due to that anemic piping. The lack of venting is amplifying that issue, and if I was a betting man I'd say the boiler is oversized.

Did you mention your location? We may know someone competent in your area, as you obviously haven't had the yet.

neilc

Are the mains good in the basement ?
Do you have one in that 4th return?
after that, and only after that,
try to speed up venting on the cold rads,
and slow venting on the hot ones, and at the thermostat.

EzzyT

So I look at the most of the steam system earlier today. 1st floor is all 11/4” Slant/Fin black pipe with steel fin baseboard, 2nd and 3rd floor are cast iron radiators, couldn’t get to the 3rd floor but homeowner will get me the measurements and pictures of the ears so I can finish up and size the system EDR.
There are 4 steam main 2- very short ones and 2 longer ones. Steam mains are piped off of bullhead tees which have to go.
The boiler is way over sized even without finishing the edr calculations and the near boiler needs to addressed along with the main venting and system piping insulation.