Constantly filling steam furnace

Jessie

My house has a one pipe steam heating system. The furnace is a manual fill gas furnace. When we first bought the house 4 years ago you only had to fill the furnace every two weeks or so. Last winter we had to fill it constantly, sometimes more than once a day. Also, 4 years ago we knew you filled it until the glass tube was half full so you wouldn't over fill it. Now you can only add a tiny bit of water or it immediately overfills (I assume this is why we are filling it constantly). We have had it serviced every year and nothing was ever mentioned as a problem. Do you have any idea what might be wrong?

BobC

Partially Blocked ports

If the water level looks low in the glass tube does that change if you wait for the boiler to be hot or cold? Does the water in the glass look reasonably clean?



Sometimes the brass fittings that the sight glass fits into become blocked with sediment, have someone remove that glass and make sure both ports are open to the boiler.



Check to make sure nothing looks like it is leaking at the boiler or any of the piping in the cellar including the radiators themselves.



Bob

Fred

Sight Glass valves

Also make sure the valves at the top and bottom of the sight glass are open and remain open at all times. The only time they shoukld be closed is if the glass breaks or if you are removing the glass to clean or replace it.

nicholas bonham-carter

Mysterious water disappearance

The definitive test for finding a boiler leak is overfilling it above the top when cold, and letting it sit like that for a day. Any leaks in it will be seen underneath or in the firebox.

Why don't you do that first, and then report the results.

There could also be some sort of vacuum situation which holds the water up in the returns, but check for a leak first.--NBC

Fred

Doubt that it is a leak

I'm doubtful that they have a leak but it doesn't hurt to check. If they had a leak, putting a tiny bit of water in it wouldn't make it come up to over-fill in the sight glass. The idea that there may be a vacuum is a better bet and when he puts a little water in, he is essentially breaking that vacuum. As I suggested earlier, make sure the valves on the sight glass are fully open, both top and bottom and check all of your main vents and radiator vents. It is highly unlikely that they all would have failed closed but at least check them. Also, what is your pressuretrol/vaporstat set at and is it working? If the pressure is too high that could keep your vents closed and create a vacuum. Pressure should be set to cut in at a half pound (.5) and off at no more than 1.5 pounds.

Jessie

Thank you! I talked to the guys at a local place and they called it a "surge problem." Does that sound right? They gave me Silver King Squick to add to the system. Does that sound right? I guess we'll find out when I fire it up for the season.

KC_Jones

If it's the surging that is talked about on here a lot that only occurs while the boiler is actively firing and it is due to oils in the water. The easiest way to fix this is with skimming (if you have a skim port). In reading your original post it doesn't sound like this is your issue. Unless you recently had pipe work done to your system or it was never skimmed when new?! Do you know how old the boiler is? You have gotten some good suggestions above and a few questions thrown out. Have you had the sight glass valves checked for blockage? You mention having the boiler serviced every year are they doing this? Is the company you are using for service an expert on steam systems? Do they know what trouble to look for?

Fred

I'm with KC on this one. You can add the Squick but in the end, that boiler is going to need a very good skimming, maybe 2 or 3 before the water settles down. Have it skimmed and see if that fixes your problem. If it runs good for a couple weeks and then starts to do the same thing, skim it again. Sometimes it takes a few skims to get all the residual oils out of the system.

JStar

I know what's wrong...your contractor! Are they cleaning the sight glass every year, and flushing the boiler?

KC_Jones

"Cleanliness is next to godliness" My father first told me that when I was a kid and it has always stuck with me. I might be a slob and have a sloppy workshop, but when it comes to anything mechanical I take care of it. It's important for the inside of that boiler to be kept clean and your contractor should be doing that. Flushing the boiler cleaning the sight glass, pigtail on your gauge, burners...and the list goes on. If they are not doing this, I agree with JStar you have a contractor problem in addition to a possible boiler problem. I maintain my own equipment, but if I was paying someone I would be keeping an eye on them until I was confident in what they did. Just my $.02

Jessie

I cleaned and replaced the sight glass and everything is working there. I don't have a leak at the boiler. I did have one vent that was stuck open and leaking steam (causing the need to fill it every two weeks), but that predates the constant filling and the overfill problem. A vacuum sounds plausible, but when I asked the guys at the local shop how to fix that, they mentioned the surge problem.

You're right, the service people suck. After this problem started I started researching steam and I've figured out how much I didn't know. I'm pretty sure the service people were just checking the boiler for the safety stuff and signing their initials. I'm now trying to learn as much as I can so I can do most of the maintenance myself. The sight glass had not been cleaned and the boiler hasn't been flushed since I bought the house. I've always had forced air heat before and I just trusted the techs to tell me if something was wrong. Lesson learned. Actually, I don't think the techs knew anything was wrong. I don't think they really knew much about steam heat...

How would I fix a vacuum? All of the radiators heat up well. This last winter we weren't using one of the bedrooms, so I shut off that radiator. Any chance that contributed to the problem? I'm attaching some pictures. I don't know how to check the cut off pressure. It appears that the cut in pressure is set to .5.

The boiler is 25 years old.

We Got Steam Heat! and A Pocketful of Steam Problems are on their way and should arrive this week.

Abracadabra

Fred said:

Sight Glass valves

Also make sure the valves at the top and bottom of the sight glass are open and remain open at all times. The only time they shoukld be closed is if the glass breaks or if you are removing the glass to clean or replace it.

This.... check that the bottom sight glass valve is not clogged. If you fill just a little bit and the sight glass suddenly fills, that tells me that the water level was just barely under the top sight glass valve. You add a bit of water and the water overflows at the top sight glass valve and fills the glass. Sounds like the bottom valve is blocked? after shutting off both valves, remove the glass and open just the bottom one and ensure that water flows freely out of the valve.

KC_Jones

From my experience turning a radiator off at the valve is never a good idea. If you have it open now that shouldn't be an issue. Generally speaking on one pipe those valves don't close all the way and basically turn the radiator into a water trap. Also closing off a radiator makes your boiler over sized which never helps matters. As far as leaks, if you aren't sure check every single pipe you can find just to be sure. It's not just leaks at the boiler as you stated it could be a leak anywhere. Look for "rusty drips" on the fittings. Fittings can be rusty, but will general get an even coat of rust if any. If you see what looks like water was dripping down the fitting, but in rust be suspicious. Might be current might be old, just one thing to look for. Another culprit could be a bad main valve leaking water or steam or both. Just posting some thoughts as they pop into my head.

Fred

I doubt if you have a vacuum problem since you mentioned a main vent was stuck open. That would have prevented a vacuum from occurring so we can probably eliminate that as a possible issue, at least for the time being. To adjust the the Cut-out pressure setting, loosen that screw at the bottom center of your pressuretrol. You will see a white wheel inside with some numbers on it. Set that wheel to "1" which is the differential in pressure from the cut-in. If your pressuretrol is working properly, that should limit your max boiler pressure to about 1.5PSI. You need to put a 0-3 pound pressure gauge on a pigtail on the boiler so you can really see what the pressure is doing. Those 0-30 pound gauges don't do much but are required by local and insurance codes for boilers. You can put a Tee on the pigtail that your Pressuretrol is mounted on and add it there. I really do believe your biggest roblem right now is the need to flush and skim that boiler. Remember when you skim it, it may stabalize your water bounce/surge for a couple weeks and then it may start to surge again. That is just an indication that another skim is needed. It may take 3 or 4 skims to get all the oils out. do put that 0-3 pound gauge on there and make sure the Pressuretrol is doing its job. There is a way to adjust (calibrate) them (see instructions below). You can try to adjust it if it is off before you spend money on a new one which still may need to be calibrated. If you do try to calibrate the Pressuretrol, you must have the new gauge and you must watch the boiler through a couple heating cycles to see what your adjustments did so plan to spend a little time near that precious boiler. It is your friend.
Pressuretrol Calibration:
If you see the pressure on the low pressure gauge go much over 1.5 to 2 lbs follow this procedure to re-calibrate the Pressuretrol:
Inside the Pressuretrol, right below the micro switch, there is a pivot arm. At the end of that arm you will see a screw pin that is activated by the diaphragm at the bottom of the Pressuretrol. If you look very carefully at that screw pin, you will see it actually has a tiny (I mean tiny) hex head on it. It takes a .050 hex wrench and you can turn it clockwise (Towards the bottom of the Pressuretrol to decrease the Cut-out pressure or counter clockwise to increase the cut-out pressure (which none of us want to do but who knows, your Pressuretrol may be really screwed up!). Turn the power to the unit off first. You may find the first attempt to turn that screw a little bit stubborn (relatively speaking) because it has some Locktite on it but it does turn. Don't turn too much, a tiny fraction of a turn goes a long way towards getting it adjusted where you want it (maybe 1/32 inch turn to start with) . You may need to play with it to get it exactly where you want cut out to be.

CLamb

Fred, does that gauge have to be rated for steam or because it's on the pigtail can it be an air gauge?

Fred

I use this model: Stock #:33020 Brand:WIKA Series:611.10 Mfr Part #:9851925 - You can see it at this site:
http://www.valworx.com/product/low-pressure-gauge-25-0-3-psi/low-pressure-gauges-25-lower-mount#sthash.48H8bShe.dpuf

It is usable for gaseous media but does require a pigtail to protect it from steam temps. Media temps up to 140 degrees.

Jessie

Here is my current plan of action:

1. Replace sight glass and washers. Done.
2. Clean bottom sight glass valve. Done.
3. Replace main air vent. Finishing tonight.
4. Open valve to spare room.
5. Flush system.
6. Add Squick, run, and flush again.
7. Adjust cut-out pressure.

I'm hoping these things will get the heat limping along since our house is currently freezing.

8. On the next warm day, skim.
9. Add 3 lb. pressure gauge.
10. Calibrate pressuretrol.

Does this seem like a reasonable plan?
From there I can deal with all the other stuff I now know is a problem and not just an annoyance - uninsulated pipes, hammering, too cold and too hot rooms, etc. After this, we better never sell this house!

KC_Jones

Having a plan of attack is always a step in the right direction. I think your idea of getting the low hanging fruit (since you need to get the heat on) is a good one. I think you should also add
11. Become obsessed with steam heat since it's awesome. Seriously though knock out those items and then address the rest is a good plan to me. Start in the basement and work your way through the system. Once you get it running right and tuned in you will be shocked how nice these systems can run. Since a lot of us are curious on this site would you mind posting some more pics of your boiler and piping? That could lead to possibly some more suggestions to your plan of attack. Do you know the age of your boiler? You can actually put the serial number into Weil Mclain's website and it will tell you the manufacture date...that is sometimes nice to know!

Fred

Sounds like a plan. Just remember, you may not see the improvements you want until you complete #8 and #10 on your list so don't be discouraged and don't let a warm day slip away from you without skimming. It can be a long winter and very stressful to watch that water level bounce wildly in that sight glass. One more very important thing to add to your list, make sure the LWCO works properly. It sounds like you have a manual water feed (as do I) so it is very important that the LWCO works like it is suppose to. To test it, when the boiler is running, open the Blowdown valve. Be careful not to let that boiling water splash back on you. In a matter of 2 to 5 seconds, the boiler burner should shut down. Close that valve and the burner should kick back on. If it doesn't shut down, you MUST replace the LWCO or get it serviced. Not an option to wait for a warm day!