Gravity Boiler Troubleshooting

[pureinsanity]

Any of you hvac guys know what my problem is?

Last year my early 1900's octopus gravity fed converted to natural gas gravity boiler was working great. Around spring it pretty much stopped heating the up stairs. It was spring, it wasn't that cold at night so I just didn't care. Now I fired her up, bled the lines and no heat upstairs.

The main level bleeds water instantly. the upstairs is getting pressure as I can bleed some air out of it ever day but no water yet. I am thinking im not to the point of air lock, just not getting things hot enough to get upstairs.

I don't want to add water as I am already at 20psi. There is no pump on this it is OLD. I have emptied the expansion chamber and filled it back up as well thinking maybe that would re-prime the system.

My next step tomorrow is cranking the heat up to 80degrees and once it is that hot go and bleed the lines upstairs. Maybe the extra hot water while releasing the air out of the radiators will force water up there. I have a friend who swears by this method.

My other option is to drain the system completely and refill it and bleed all the lines. My worry is if I do this, I might end up having no heat and calling in for professional help which could be costly. I can live with out the upstairs being heated completely but I would prefer to have it working correctly.

Any ideas? HELP please!

[Surface Tension]

If your not getting any water coming out when you bleed the radiator then there is air in it.

Your gauge might say 20 psi but it can be compressing air.

[Tom7227]

I bet less than 10% of the people on FM have a clue what this thread is about. Grandpa Welsch used to keep me entertained as he screwed around with that monster in the basement of his house on Rice Street.

[Surface Tension]

I bet less than 10% of the people on FM have a clue what this thread is about. Grandpa Welsch used to keep me entertained as he screwed around with that monster in the basement of his house on Rice Street.

I've had the pleasure of removing a few of those.

Last time I used one was years ago. Coal fired with a hopper and auger feed.

If you add water don't do it with a hot boiler.

Wouldn't hurt to shut it down and drain/flush and refill.

If that doesn't get you going call in a professional.

[Archerysniper]

I still run into those monster in home in Minneapolis. If your getting air it"s not going to work your going to have to keep bleeding and filling till you get water. Like Surface said it would do no harm to drain and refill the system.

[Jim Almquist]

If air is the problem you will want to remember which spot fixes the problem because that will be the highest point in the system. In my house it was the kitchen so that was always the first spot to start bleeding. If I heard knocking I knew it was time to bleed and check to see if it needed more water.

[King Canada]

Every once in a while I'd have to remove the bleeders and boil them out. Used one of these wood fired for 20 years.

[delcecchi]

I bet less than 10% of the people on FM have a clue what this thread is about. Grandpa Welsch used to keep me entertained as he screwed around with that monster in the basement of his house on Rice Street.

Isn't it just like the old octopus convection air jobs only with water? My son had one, just like the one I grew up with. Gas conversion. Originally coal.

[pureinsanity]

Well I cranked the heat up to 83, bled some air out and still nothing. I was hoping that would do the trick.

I did hear gurgling in one, well I shouldn't say gurgling but air coming up through water in the pipe. So I know there is some water in that pipe someplace. It is just how far down???

Every day I can bleed some air out. some days more then others. Each radiator will blow out some air. I guess I can either keep bleeding it until it gets cold and hope it works.

Or like stated drain the system and refill and bleed. The one thing is that worries me is what if something is wrong and I refill the system and then I can't get any of them to bleed water. All hypothetical just do not want to spend the money on a new system right now.

Secondly, boilers are all new to me. When refilling them, how full do you fill them? there are no sight gauges, and I watch the pressure gauge obviously. But if my gauge is reading air pressure by compressing air I can't really fill it because the more water I add the more the psi goes up whether it is reading AIR or Water.. Do not want the blow out valve to trip.

thanks

[Tom7227]

isn't there a water tank that sits up high, like attached to the ceiling? I would guess there's some sort of glass tube jobberdo attached to that which gives the level of water.

I am curious about why success might occur if the entire system were drained. My simple mind tells me water is water and that the air will migrate up with old water the same as with new water.

Second thing I wonder about is whether you need to put something in the water to slow down corrosion. Could his problem be that there is at least a partial blockage someplace that is preventing the air from getting where he needs it to go?

Again curious but what would be a reasonable price range if he wanted to put in a new boiler and would he have to do a lot of changing to the existing radiators?

[Surface Tension]

You can bleed this till the cows come home but till you fill it with water you won't get any heat upstairs.

Reason to drain is to flush out the sludge but forget that for now because your trying to get the air out and water into of the system.

Once you figure that out then you can drain it later on.

Do you know where the expansion tank is? It should be up high like in the attic.

Look for a sight gauge on the tank. Don't worry about overfilling it.

The 20 psi your reading should be static pressure. That would be the weight of the water since the system is open.

If you had a plug then its possible you'd compress air when adding water but I doubt its plugged but maybe dirty.

If you add water that(psi & sight gauge) should go up.

If you add too much water it'll go out the vent. That vent comes out of the expansion tank and out the roof.

Where to add water is the million dollar question. Could be at the expansion tank or you could have an auto fill valve or a fitting in the basement to fill. You'll have to look around.

When you go to fill you have to open the vents on the radiators. The air will vent out the expansion tank but you can still get air locked so open the vents and close them as water comes out.

There is a conditioner you can use but considering the age and amount of rust you have a little build up is the least of your concerns. I would use that on a new boiler.

[pureinsanity]

You can bleed this till the cows come home but till you fill it with water you won't get any heat upstairs.

Reason to drain is to flush out the sludge but forget that for now because your trying to get the air out and water into of the system.

Once you figure that out then you can drain it later on.

Do you know where the expansion tank is? It should be up high like in the attic.

Look for a sight gauge on the tank. Don't worry about overfilling it.

The 20 psi your reading should be static pressure. That would be the weight of the water since the system is open.

If you had a plug then its possible you'd compress air when adding water but I doubt its plugged but maybe dirty.

If you add water that(psi & sight gauge) should go up.

If you add too much water it'll go out the vent. That vent comes out of the expansion tank and out the roof.

Where to add water is the million dollar question. Could be at the expansion tank or you could have an auto fill valve or a fitting in the basement to fill. You'll have to look around.

When you go to fill you have to open the vents on the radiators. The air will vent out the expansion tank but you can still get air locked so open the vents and close them as water comes out.

There is a conditioner you can use but considering the age and amount of rust you have a little build up is the least of your concerns. I would use that on a new boiler.

The Feed and Expansion tank is in the floor joists in the basement. I have already shut off the feed, drained the tank. I then opened the feed back up and it fills up for a little bit, about 1.5 - 2 gallons of water. It is my understanding these should never be filled full and it is supposed to only have a little bit of water in them. I believe there is a float or something inside of there. To my knowledge their is NO sight gauge. I will have to check the tank again.

So there is no expansion tank or relief that goes out my roof.

I add water by connecting a hose to the drain, and then opening the drain. That appears to be the only way to add water. When I do add water I watch the PSI gauge. once it hit 25 I stopped adding because I did not want to blow anything out. My friend told me at 30 psi they blow out and you really don't want that. By the looks of my wall in the basement its blown out a few times before.

I have never had the vents open when filling and that could be a problem. I always tinker with it when I'm home alone. I will try tonight opening all the vents and pushing some water in.

I think in my case because im at 25psi on average it might be best to drain the whole system and refill it with all the vents open until water comes out.

I will want to be filling this thing and watching the gauge. Also I wonder if the blow out valve when it blows out will it need to be replaced or is it as simple as resetting that valve?

[pureinsanity]

isn't there a water tank that sits up high, like attached to the ceiling? I would guess there's some sort of glass tube jobberdo attached to that which gives the level of water.

I am curious about why success might occur if the entire system were drained. My simple mind tells me water is water and that the air will migrate up with old water the same as with new water.

Second thing I wonder about is whether you need to put something in the water to slow down corrosion. Could his problem be that there is at least a partial blockage someplace that is preventing the air from getting where he needs it to go?

Again curious but what would be a reasonable price range if he wanted to put in a new boiler and would he have to do a lot of changing to the existing radiators?

I have a really good deal on a newer boiler that is big enough to heat my house. (from a laundry mat)

the problem is the asbestos that needs to be removed to remove the old boiler and fit new pipes. I am afraid what that would cost. So the boiler and hooking it up doesn't bother me.

[Surface Tension]

Since I can't see what you have and this has been changed over I think you need to have someone come in and have a look.

[pureinsanity]

Ill take some pictures tonight!

[pureinsanity]

Alright you ready for this beast?

Drain

F & E Tank with NO sight gauge

No clue what this is but its capped off. I am thinking maybe at one point this was piped in for filling the boiler? Looks like its a one directional fitting.

[CAMAN]

That last picture is a water pressure reducing valve. It is used to lower the water pressure from the city water supply down to a specific pressure. It was used to automatically keep the boiler topped off if there was a leak or you had some air settling in the lines and the pressure dropped below the set pressure, and in your case it looks like 12psi.

[pureinsanity]

Ok after a quick google search that red valve is a reducing valve that helps control pressure when filling the boiler with water. So sounds to me that is my first issue. Someone had taken the water source away. So filling from the drain valve/pressure relief valve is creating too much pressure whether it be air or water. So sounds to me I need to get a plumber out or attach some type of valve I can attach a hose to to fill the boiler. Maybe this would control the pressure when filling from the drain.

[pureinsanity]

So my question is. Can you fill from the drain? Or are you to fill from the reducing valve? I am assuming the reducing valve is more for adding water or topping off a system?

[Surface Tension]

It isn't as old as I thought.

Pic 4 is your expansion tank and should be charged with air.

Does the pressure drop after you open the vent on the radiator and if so to what?

The pressure reducing valve should be hooked up to the domestic water supply line. Again its been changed and we don't know why and what. Could be because of a code. Sure would be nice if it was hooked up and you could bleed the air out the vents.

Has this thing been converted to forced water with a pump and if so is the pump turned on?

Pic 3 pressure relief valve and drain. Unless there is a better spot I'd fill there as to not goof up the air in the expansion tank.

Might seem too obvious but are there any valves closed anywhere?

When you vent is it possible your hearing air sucking in instead of blowing out?

Sort of going back to the original problem which is no heat upstairs, it shouldn't be that complicated and something simple is being overlooked.

[pureinsanity]

It isn't as old as I thought.

Pic 4 is your expansion tank and should be charged with air.

Does the pressure drop after you open the vent on the radiator and if so to what?

The pressure reducing valve should be hooked up to the domestic water supply line. Again its been changed and we don't know why and what. Could be because of a code. Sure would be nice if it was hooked up and you could bleed the air out the vents.

Has this thing been converted to forced water with a pump and if so is the pump turned on?

Pic 3 pressure relief valve and drain. Unless there is a better spot I'd fill there as to not goof up the air in the expansion tank.

Might seem too obvious but are there any valves closed anywhere?

When you vent is it possible your hearing air sucking in instead of blowing out?

Sort of going back to the original problem which is no heat upstairs, it shouldn't be that complicated and something simple is being overlooked.

This is an old boiler, Perhaps some day there was a feed and expansion chamber in the attic. My house was one of the first to have running water on my street according to some older local towns people.

If there WAS a tank in the attic, it is now down stairs and is a closed system for more efficiency.

There is no pump on this thing. I wish there was! This baby may be up to par on some technologies but it is still lacking a lot! It is still gravity fed.

I know for a fact air is coming out when I bleed lines. I can feel it, and I listen to my lines. One of them gurgles with air coming up through the pipe. The only problem is I don't know how far away the water is because the pipes resonate so much when empty. The lines only bleed for 10 seconds at max. and psi goes down half a psi IF that.

I have closed off some of the lower radiators to try and force more hot water upstairs with no luck yet. I think I flat out do not have enough water in the system. But when filling it I watch the gauge and it rises fast. Fast water means air in my opinion.

As for the expansion tank. My understanding is when a boiler builds pressure, it is forced into the expansion tank where pressure is built and stored.

the simple over look is NOT enough water. The problem is im at 25 psi already. Adding more water will put me at 30 and blow out some valves. I can't add more water with this build up pressure.

If I could figure out how to relieve the pressure it wouldn't be an issue to me.

[pureinsanity]

That last picture is a water pressure reducing valve. It is used to lower the water pressure from the city water supply down to a specific pressure. It was used to automatically keep the boiler topped off if there was a leak or you had some air settling in the lines and the pressure dropped below the set pressure, and in your case it looks like 12psi.

Is this how one is supposed to fill the boiler? or can they fill it from the drain?

[CAMAN]

Yes, that would be the recommended way to fill the boiler, and is probably the reason why you are already at such a high pressure. The system should be no more than 12 psi (or whatever is on that pressure regulator) when everything is COLD.

There is a reason someone disconnected it and I would bring in someone more knowledgeable of boilers to ensure everything is up to par and connect it to the appropriate location. Maybe they just didn't want to add a backflow preventer (probably code in your area) and disconnected it to save $20, maybe the pressure regulator went bad? Only they know.

[pureinsanity]

Yes, that would be the recommended way to fill the boiler, and is probably the reason why you are already at such a high pressure. The system should be no more than 12 psi (or whatever is on that pressure regulator) when everything is COLD.

There is a reason someone disconnected it and I would bring in someone more knowledgeable of boilers to ensure everything is up to par and connect it to the appropriate location. Maybe they just didn't want to add a backflow preventer (probably code in your area) and disconnected it to save $20, maybe the pressure regulator went bad? Only they know.

I am 99% sure the ol ladies old man disconnected it and plugged it worrying it was going to blow back if something would happen.

I think its time for a plumber and HVAC at the same time.

[WallEYES]

Remove the old Bell&Gossett reducing valve.