radiators not heating fully

newagedawn

hello, i have a few radiators not heating all the way, anyone know why? they only heat like half way and i have bled the rads alot so i dont think it that?

JohnNY

Maybe it's not cold enough outside and the rooms reach the themostat setting before the radiators fully fill with steam. It's very common.

Erin Holohan Haskell

What John said. And more info here:

Reasons why the radiators don't heat all the way across, and where to look for solutions
https://heatinghelp.com/systems-help-center/reasons-why-the-radiators-dont-heat-all-the-way-across-and-where-to-look-for-solutions/

mattmia2

Is this hot water or steam? Reason is basically the same, that the demand isn't enough for the cycle to be long enough to heat the whole mass of the system, but since you say "bleed" i suspect this is converted gravity hot water.

newagedawn

its hot water, last i knew you dont have to bleed steam rads? so im looking for and answers into orifices for hot water rads, any info would be helpful, its a monoflo with very old cast iron rads

Jamie Hall

Monoflo? They are finicky beasts. First of, they are very difficult to purge successfully. Second, they are also very difficult to get in balance. If the radiators aren't heating adequately, you don't have enough flow through them (and, correspondingly, too much flow through the main between their Ts). If their control valves (if any) are fully open, there isn't much else you can do short of altering the piping.

newagedawn

@Jamie Hall havnt had a problem purging the rads and only one rad sometimes gives me problems heating up but it comes around ,lol i know the water through the rads are good but as the rads heat up, the bottom half gets hot nicely but only the last 2 sections top get hot, was wondering if orifices would work? to slow the flow through the rad to help heat the other sections top part? and yes monoflo systems are difficult, almost ready to pipe each one through a manifold,lol as i like the heat they provide and they are very nice to look at

mattmia2

So the big question here is do they adequately heat the space and do they evenly heat the spaces? Something like a full port ball valve on spaces that overheat that you can close a little bit but offers little restriction to flow might be something to try to slow those spaces down. Another option might be to lower the supply water temp so it runs longer cycles. If it is a conventional boiler that might involve adding a bypass of one form or another on the boiler.

If it is heating adequately and evenly, leave it alone.

JUGHNE

What is the supply water temp?

newagedawn

@mattmia2 the big question here is WHY DONT THE RADS HEAT ALL THE WAY,only the bottom part gets hot and the last section on the return side gets hot all the way, im finding it hard to find someone that knows about orifices,lol,looks like ill have to experiment,lol let you know what happens

mattmia2

Why do you need the whole radiator to heat? Is the radiator matched to the load such that you need the entire surface hot to match the heat loss during the relatively mild days we currently have? If you need that now, it won't keep up on a design day when it is running longer and more frequent cycles that does heat the whole mass of the system. It is also very likely to overshoot this time of year if you do manage to heat the whole mass of the system.

Jamie Hall

May I reiterate what I said above? If this is a monoflo system, as you say, any restriction in the radiator feed or return -- orifice, whatever -- will result in reduced heat from the radiator. Also, as I said, monoflos are touchy. If it's heating the space adequately, don't mess with it. Just don't.

Alan Welch

Are the radiators connected across the top?   They may be steam radiators.

retiredguy

Take a picture of the rad that does not heat and post it here. Is the supply pipe above or below this radiator? Does the water to this radiator flow up from below or down from above? How large is the radiator? Is it the largest one in the house?

Danny Scully

@newagedawn, what do you want us to tell you? We’ll tell you whatever you want to hear 😉🤣

newagedawn

@retiredguy the pipes come in and exit from the bottom, they are 3/4 in and out, i get flow and they do heat as the others have said, but im wondering why only the bottom and 1 section on the outlet heats to the top, i would like the whole radiator to heat, wondering what can be done, as the rads are beautiful old ones

JUGHNE

Nice looking rads! Are those typical of your problem items?

Where are the air bleeders located?

What does the "For steam only" imply?

JUGHNE

Hello....??

Danny Scully

Yea I’m with you @JUGHNE. Although the sections appear connected at the top, there has to be something behind that embossed “FOR STEAM ONLY”.

JUGHNE

They look pretty unique, has anyone else seen these?
I like them, great paint job.

Non top connected might explain why hot only across the bottom, lol, and the end section gets hot (the one with the air bleeder) lol,

Could this be the answer to the "big question here....WHY THE DON'T THE RADS HEAT ALL THE WAY".?

Alan Welch

That's why I asked.   I can't tell from his pictures. 

Jamie Hall

Not hard to tell, folks, since they aren't connected to anything...

Turn one upside down and pour water into one end. And see where it gets to! Does it fill one section first, and then spill over to the next? Or does it fill the whole thing?

retiredguy

Is there a name on the radiators? Look all over the radiators for a name especially near the bottom and post a picture of one of the rads looking straight at the radiator. Do you see any through bolts or rods that are holding the radiators together. Also take a picture of the top of one of the radiators. One more thing to try if possible; can you make a fill tube using small tubing, say 1/4"OD copper, that will adapt to a hose or some water supply to fill the first section and see if the water fills only that section first before it spills over into the next section or does it fill all the sections at the same time as @Jamie Hall has asked. Everyone wants to know if the tops are connected with through nipples or just held close together.

newagedawn

@JUGHNE yes those are the rads, acouple were taken out of a 1870"s building my guess is, original!! thats why no one has seen them,thats why they are so special to me and im so determined to make them work, they are really really old and thats why i ripped out my baseboard and installed these, as we all know rads are far superior to baseboard heat, plus the fact that they super super cool to look at !!!, im looking for an artist to color them,.. the bleeders are on the other side, and yes a couple were taken out of steam systems, i converted them to hydronic ( i drilled and taped them myself and painted them) yes, i have others hooked up that heat all the way across, so lets put the not filled to top to rest!!!! as i have others that work awesome!!!, thats why i know its a flow issue and not the other issues all have spoken ( this aint my first rodeo,lol) i have read all the monflo books i can get my hands on even bought original b and g and taco books on the subject and even ran the numbers my self, several times!!!!! thats why i know its a flow issue, cause as a really really smart man once said " when you bleed if you dont get any air it aint an air problem" sound familiar? im going to try making my own orifices to see if that works,.......ill be in touch, if i had a infared thermometer i would prove that others heat all the way across and put to rest all the other comments, but those dam things are to expensive,.... if anyone can talk to me about flow and why rads dont heat all the way, i would be more that appreciative!!!!!!! and grateful!!!!!, tx all for your comments, ill be in touch when i figure it out!!!!!!! hopfully i can find an artist to paint those really old , really cool old beauties!!!!!! that have made it into the 21 century and hopfully on to the 22nd,lol again tx

newagedawn

@retiredguy the first one is the biggest one for sections and btu, it heats all the way top bottom all sections, the next is one i havent painted yet, and the cover is missing that says "steam only", im going to take one from another rad and put it on that one, i wanted to make sure it didnt leak,lol, as the other one before it did leak on the bottom at one section, sucks, but i will fix it in the spring and also now that im talking about it, that non painted one had a small leak in the middle section on the top that i fixed with JB weld so yes there are rods across the top and bottom and yes the water does go through all sections top and bottom, so lets put that to rest!!!!! for all those asking, its a flow problem !!! hopefully orifices will help as these rads are on the first floor with very little pipe from the main to the rads, maybe i have to split the monoflo tees farther apart to create more of a pressure drop, its alot of work and i will gladly do it but i wish i had a solid answer before i open the system adozen times to figure it out!!!!!!!

SuperTech

Forget about fiddling with different orifices. If its a flow issue install a Caleffi balancing valve with flowmeter. You can use it to increase/decrease the pressure drop to radiators and dial in the flow to where you want it.  
Nice radiators!!!! Thanks for keeping them in service. 

WMno57

Your radiators are very nice! Are the rods that hold the sections together wet? Neat feature, as it keeps the rods out of sight. If they are wet, I wonder if it would be worthwhile to remove and replace the rods?

WMno57

or, the top rod is dry, there is no separate water passage from the rod passage, and your radiators are "for steam only".

newagedawn

@WMno57 yes they originally were steam rads but, a rad is a rad why cant i convert it to water, as i said the others work, i like to think outside the box,lol, just had to drill and tap them,tx and like you said cant find rads like this anymore!!!!!!!!!

Jamie Hall

newagedawn said:

@WMno57 yes they originally were steam rads but, a rad is a rad why cant i convert it to water, as i said the others work, i like to think outside the box,lol, just had to drill and tap them,tx and like you said cant find rads like this anymore!!!!!!!!!

They will work for hot water -- if, and only if, the water can move freely between sections at the tops of the sections as well as at the bottoms. If that's what you've done, @newagedawn , with the drilling and tapping, they should work. If not... there's no way to get the air out of them, except for the one with the bleeder, and there's no way for water to circulate in them other than convection, which is slow to the point of being useless.

JUGHNE

I wonder if these "steam only" rads had each section cast with the top of solid iron. With the tubes from bottom sections just dead heading at the top.
Then perhaps the tops of the solid sections was drilled for the rod to pull the dry portions tightly together giving the sleek look along the top. The end caps would cover the dry rod nut.

Perhaps the working ones are different design.

So much cleaner than the loose look of old time column rads.

Could we see the end shot of the rads that do heat correctly?

WMno57

newagedawn said:

i like to think outside the box

Me Too! Those radiators are too nice not to use. I'm thinking you should acquire a steam boiler.

SirMichael

What about saving the energy in your room? In case your heaters do not work properly you should also consider your home windows and if they require replacement.

Steamhead

Those are H.B. Smith radiators, likely the "Imperial Union" model. And they will not work well on a hot-water system. They're not kidding when they say "For Steam Only".

If you want those rads to work well, you'll have to switch to steam.

newagedawn

@Steamhead @JUGHNE yes , you are right, i cut one open to verify,.. they are old school column rads for steam, so im faced with a decision let them heat half way, which they do well or go crazy and tear them apart and get a friend of mine to make press nipples for the top and bottom, which considering the age probably not a good idea, uugghhh,... anyway they are beautiful rads, ill probably leave them cause as i said they do heat my house well,
on a side note, i have an alpha pump and it has pressure setting on its features i have used the medium pressure setting and it has improved the heating in the rads it pushes the water father up into the column cavity, huh, who knew,lol, tx to all who have given time to this heating issue, its been an honor to discuss this with you all!!!!!!!! God bless you all

Danny Scully

You finally answered our question @newagedawn, the radiators heat the space fine. Glad we could be of assistance to talk you through that 🤣 😉

Alan Welch

I recall pictures on this site where someone pit bleeders on each section.  Someone else looped all sections together with small tubing.  Not recommended. 

Solid_Fuel_Man

I honestly wonder with a good micro bubble air elimination if given enough time these would fill more. Slow use of makeup water over a year or more as the air is absorbed into the water and vented out the air elimination point. 

I do remember an article @DanHolohan wrote that told of a dead man who didnt use an expansion tank in his water system. He just never installed bleeders on his water radiators. The trapped air was the expansion cushion. 

EDIT: I wonder if anyone has tried using their vacuum pump on a hydronic system prior to filling. I've done it to radiant floors to duck in glycol when i forgot my transfer pump at the shop. Would pulling a pretty deep vacuum fill the rads more? Sounds like it would @hot_rod..... 

JUGHNE

I wonder if an air bleeder on each end section might give a little more heat.
And, yes you may not need an expansion tank.

mattmia2

Raising the system pressure will make the air pocket smaller and make more dissolve. If you have your air separation where the highest tamp and lowest pressure are you can probably eliminate the pocket as @Solid_Fuel_Man said. i really think you can do it if you are pumping away, have a microbubble air eliminator between the boiler outlet and the pump and raise the pressure at least temporarily. Of could raised pressure could find leaks in your 100 year old radiators.

Lower swt and longer cycles will give the water more time to circulate in the radiator by convection and to heat the mass of the radiator by conduction.

newagedawn

@Solid_Fuel_Man @JUGHNE @mattmia2 i have considered bleeders on all section, but to tacky, cant bring myself to do it,lol i do pump away and have a spirovent, like i said my alpha pump has pressure settings right now im on the middle setting it has seemed to push the water higher as the first rad in the series has heated all sections now that its been running awhile, i hope the others will catch up, either way thank God i did over size 25% on my heat load calcs for each room so the house does heat!!! at the end of the cycle the t stat actually goes up 2 degrees from the set temp which makes me happy !!!!, i have spare ones maybe in the spring ill get a friend of mine to make me new press nips and i will try to totally convert to hot water. not to excited tho as that 140yr old cast probably wont like new steal, its to hard not soft like old steal used to be. anyway,.. happy new yr to you all and my old rads my they last another 140,lol