Will new return help my spitting radiator problem (steam heat)

Debbie_6

Hope these are helpful.

Debbie_6

Return needed in one pipe steam system?

I have a one pipe steam system in 100 year old house. This year, we replaced 3 original radiator with recessed radiators. This caused all kinds of havoc with the sytem - klanking and spitting from vents, especially in the 2nd floor radiators above the new recessed radiators. $800 with my plumber and we got the banging and spitting under control by 'squicking' the boiler and turning down the vents in the new radiators under the assumption that they were condensing faster than old radiators and water was being pushed up the pipes by steam attempting to go up to 2nd floor. I also had to put the vent on one upstairs radiator to almost closed so prevent it from spitting.

That seemed to work for a while. However, now that it is really cold outside, I'm getting more clanking and spitting from the 2nd floor radiator with air vent mostly closed, I'm assuming because the boiler is 'working harder'. I want to be able to turn my new recessed radiator vent to full open to get the most heat out of them, but this causes the klanking, gurgling (like there is water in the radiator rather than steam), and spitting upstairs. My plumber and I had talked about a new return pipe from the new recessed radiator back to the boiler (or to somewhere behind the pipe upstairs to the trouled radiator) so that its condensed water doesn't collide with steam trying to go up the 2nd floor. Does this sound like it will work?

Also, the new recessed radiators make a lot of popping sound as steam hits them. My plumber says that is because the piping connecting them to my prior iron piping is copper and it is contracting/expanding. However, the popping seems to come from the radiator itself (I believe these are Burnam recessed radiators). I'm wondering if this popping (intermittant for about 1 min. as steam cycles through) is something I have to live with or an indication that they were improperly installed or defective in some manner.

Sorry for verbose description and non-technical language. Any advice appreciated.

ed wallace

spitting rads/vents

copper is not a good thing on a steam system did the plumber keep the pipes same size as the old black iron pipes are the radiators pitched upwards toward the nents any pictures you could add to your posting?

Brad White_191

Express return line and it's not the day after Christmas...

Personally, I want to step back and take a more holistic view of the system, what it was before (assuming it worked well, quietly and quickly), and what it is now.

That is, before we go doing surgery, might some minor medication work as well? Or just "undo" some of the less ideal features added when the new radiators were installed.

Is what changed just the three new recessed radiators and what was there before? Regular standing radiators?

Are the new radiators on the first floor? You mention that the second floor radiators now have spitting and clanging (where there was none before), is that correct?

That some of the new piping is in copper is of some concern but not absolute. Copper joints compared to steel and iron pipe and fittings, tend to work loose over time. A time factor so far is not at issue because the problems you are having are immediate.

I suspect some pitch issues, either as a cold installation or that the pipes may be level when cold then expand to pitch against return flow.

Basically, I would want to change the system as closely back to what it was before we go installing express returns. Will express returns work? Yes, they can, if they drop down to below the waterline (to a "wet return").


There are other global issues and factors which may also have changed.

For example, was the operating pressure increased? It should be as low as possible, under a pound and ideally a half pound cut-in pressure to maybe a pound cut-out pressure. (Less than this requires a vaporstat for ideal fine control; a pressuretrol can get you to the one pound range less a differential, but that is pushing it.)

Was any near-boiler piping changed? If so, can you post photos?

Were the new radiators extended from the old risers serving them or are they entirely new?

Was the piping insulated and now is bare? Any of it, but especially the radiators served?

Lots of variables, just want to narrow them down.

Terry in NJ

Are the recessed radiators on outside walls?

if so, they are exposed to cold one side and that is causing the quick condensing of steam to pop.
some comments from a homeowner:
-do you keep your system at a constant temperature or set back?
-Are the new radiators smaller than the old ones? did the entire system get rebalanced. Are all of the air vents adjustable?
- Post some pictures of the boiler and its piping so the pros can point out any problems.

Debbie_6

Thanks for responses.

The replaced radiators were regular standing radiators. They are all on the 1st floor of the house. No other piping was changed - just the immediate piping to connect the new radiators being moved from coming up through the floor to being back in the wall with the recessed rads (risers not replaced, just cut where they would have come up into the room for the standing radiators and inch or two added to extend them to the wall and then up).

Operating pressure was not increased, but I'm not sure what it is. Piping in basement is not insulated, but was not insulated before.

Behind the radiators a sheet of metal was installed to radiate heat outward, but no real insulation was installed. House has no insulation, by the way (working on that). My plumber has suggested at least putting some insulation under the new radiators in basement to shield them from below but we haven't gotten to that.

This is house we used to rent out, so I never lived through heating season with old radiators. However, our tenants say there was no clanging or spitting. My plumber says they never had issues, execpt with 1st floor radiator that is at the end of the line used to spit a bit, but he worked on that and we now have no issues with it.

Pitch on new radiators is about level, but the pitch on them all is about the same and only 1 causes the problem (though it is the radiator that is absolutely level while the air bubble in level at least indicates some pitching toward pipe on other 2 (air bubble in level touches left line of level). I can post pictures of the radiators w/ level on them once my camera is juiced up. Could also post pictures of basement piping going to problematic radiator. Also, the recessed radiator that sits under the 2nd floor radiator that spits/clanks is the only one of the new 3 that makes no popping noises. The new radiator that pops the most does not have a radiator above it on the 2nd floor.

My mistake - a contractor installed these radiators w/ his plumber, not my normal plumber.

Brad White_191

Good point

and observation, Terry!

Debbie_6

Forgot to answer some questions: Since they are in the outside walls, they are pretty exposed (again, house has no insulation). My plumber told me not to change my temp much because of steam sys, so we had been keeping it at 66. Last heating bill was scary, so I turned it down to 64 and at night push back to 60. Popping is evident all day, not just when I put temp back up.

New radiators are not smaller in terms of length. They are same lenght or a bit longer. I know the contractor and plumber did some calculations based on size of old radiators.

I don't think they are all adjustable, but most are. We had to put new vents on several of the radiators after the initial spitting/klanking episodes (part of $800 to my plumber). I have turned the vents down in the rad that continues to spit because if I opened it the whole way I have big problems with the klanking/gurgling/spitting. I turned down another one because the room was just too hot. New radiators have adjustable vents.

Terry in NJ

did they change the connections at the main?

sounds like the condensate is bouncing straight up. I have this on a second floor radiator which has a 90 degree elbow off the main instead of a 45 degree slope.

my guess is the one that is not a problem is hooked into an orginal connection.

Pictures of the connection to mains may help too.

nicholas bonham-carter

spittin' rads

how are your main vents[ not radiator]? too much air in the pipes, while at pressure and heat, can cause all sorts of unpredictable results. these poor devices have to let the air out from boiler, and main pipes; before the steam can arrive to warm you. if they are not working, the burner will run longer trying to squeeeeeeze the air out through the constipated openings of the radiator vents, and you know what that is like!

definitely check your pressure,with a good low-pressure gauge[gaugestore.com] and get it under 1psi. sooner or later you will need a vaporstat for this low pressure-why not now? you can check prices at pex supply, patriot supply, and state supply.--nbc

ttekushan_3

No pitch.

The 'No Pitch' is a big problem. One thing that would help would be to increase the pipe size on the new horizontal with the next size larger.

regarding your 2'nd floor spitting the boiler water is contaminated still, IMO. It takes several skimmings or surface blow off to get rid of that.

-Terry

Debbie_6

Still working on noisy new recessed radiators

Thanks for previous responses. After I posted a pic of the pitch on the new recessed radiators, someone said the pitch was a real issue. Two of my new recessed rediators are very noisy ('popping' noises when the steam comes through) and one is somehow involved in an upstairs radiator now clanking and spitting.

The contractor who put these in says his plumbers are telling him they have never heard of pitching radiators. i don't know how this could be...all my reading here on clanging pipes and radiators mentions pitch. These new types of raditors (see pics in previous posts) must be pitched, right?

Debbie_6

Still working on noisy new recessed radiators

Thanks for previous responses. After I posted a pic of the pitch on the new recessed radiators, someone said the pitch was a real issue. Two of my new recessed rediators are very noisy ('popping' noises when the steam comes through) and one is somehow involved in an upstairs radiator now clanking and spitting.

The contractor who put these in says his plumbers are telling him they have never heard of pitching radiators. i don't know how this could be...all my reading here on clanging pipes and radiators mentions pitch. These new types of raditors (see pics in previous posts) must be pitched, right?

Unknown

Hi Debbie-
Here is an explanation why there must be pitch on a 1 pipe steam radiator and the radiator's riser piping:

Steam, being a gas, flows from areas of high pressure to areas of low pressure. Steam will flow uphill, level or downhill. It will flow in any direction.

On the other hand, condensate (water) only flows downhill. Water doesn't flow uphill or flow when it is level. I find it is best to think of condensate (water) in a steam system as "sliding". If there isn't pitch to make it slide (flow) it doesn't move!

Initially steam enters your radiator and condenses back to water. This forms a slight vacuum so more steam enters (high pressure to low pressure)the radiator. If the radiator/riser piping isn't pitched, the condensate remains in the radiator/piping until it builds up to the point where it interferes with the steam trying to enter the radiator. This interference is what causes water hammer.

To make the condensate (water) move out of the radiator, there must be pitch on your radiator and pitch on the radiator's riser from the radiator to the main. The minimum pitch, if I remember rightly, is 1/2 inch in 10 feet. (The more, the better).

Obviously your contractor's "plumbers" know very little about one pipe steam systems. I imagine they are confusing it with a water heating system where a pump is needed to move the water.

Frank_62

recessed radiators

Debbie you state that before you added new recessed rads there was no problem so try this if the new rads have gate valves close them run your system at whatever temp you want see what happens if it does fine its the radiators.You should be able to select desired temp without big fuel bills. Based on your pics it seems the copper pipes are not the same diameter as the cast,this restricts the steam and the return condensate(copper is not a good idea on steam)they also show a ninety degree elbow straight up to the radiator not good you need 45 degree pitch to the gate valve so condensate slowly returns to the boiler and doesn't slam into the steam (my guess as to what is happening) the rads must be pitched back toward the gate valve supply years back we used checkers under legs on the vent side,non adjustable vents proper pipe pitch and low pressure. I know it may not seem so but steam is simple make the steam,remove the air,return the condensate to the boiler. Plumbers are plumbers steam guys are steam guys get a steam guy good luck