New Member .. Trying to Salvage My Radiant System!

gliptitude

I've been snooping around here for a month or so. I've gotten a few leads by searching the forum, but many of the threads I find are closed for new comments. .. So I'm giving a brief introduction of myself, pertaining to radiant heat and why I am here, and then a not so brief list of my various questions and dillemas. Hopefully I'm posting in the right place.

I bought an "As Is" house with cash two years ago, (heard this story before?). The house had hot water radiators through out and I knew that they had not been drained. The house had already sat vacant for over a year so I thought there was a good chance they had already long since froze and broken. I knew I should drain the system but I had no idea how to do that at the time. I know now how easy it is to do and have done it half a dozen times, but back then, about one week after I closed on the house, we had a deep and continuous freeze very early in the winter. They froze and started breaking before I even got the electric turned on.

The house is approximately 1400 SQF living space, in addition to the basement. There was a total of 7 radiators in the house. Four of the radiators broke. A couple fittings in the piping broke. One radiator broke so comprehensively that I decided to demolish it. Two others I have attempted an unconventional repair on. And the last one I am considering disassembling to remove a cracked fin and reassembling as a slightly smaller radiator.

I didn't move in to the house until last spring so this is my first winter. I'm getting by on space heaters so far, but obviously would rather have a functioning central heating system. I really want to keep the radiant.

I started out in this house with no knowledge of these systems but I have been putting together some understanding, mostly as a result of intermittent contact with a family member who does HVAC. But there are still some fundamental things I don't understand.

- Is there an organized instruction somewhere for how to remove a broken radiator fin? How to reassemble? I have read multiple posts here advising this method of repair but not a lot of follow up or documentation. The few videos I've found are not very instructional.

- All of my piping is threaded black. Can I mix PEX in this system if I am adding radiators or changing the size of a broken radiator? Is this advisable?

- Is there any risk involved with eliminating radiators from the system? Can too few radiators stress the system somehow? Or maybe too many capped pipes cause air problems?

- Every single radiator that I have disconnected has leaked at both of the hookups when I reconnected it. I used rectorseal T plus 2 on the brass unions. I tried tightening one while it was badly leaking and broke the nut. Re-threaded with JB weld. .. I switched to blue thread tape on some and rector seal number 5 soft set on others and each of those seam to be working. Is this normal that these are so problematic or that these pipe sealants would vary so much?

- several of my radiators have the style of air bleeder which has a tiny nozzle which is pointed down. These are all dripping. Is it important these point down? Is replacing this with a different one as easy as unscrewing it and screwing in another?

- When I fired up the boiler yesterday I was confused by the results. I was not surprised that some radiators heated up and that others didn't, because I had problems with the circulator pump in past tests. .. But the hottest radiator was on the second floor, probably the radiator that is the furthest away from the boiler. Among the coldest radiators was the one that is closest to the boiler. .. There can't be any valves blocking flow to the cold radiators because I just filled them the day before. Doesn't this orientation of hot and cold radiators conflict with the diagnosis of non-working circulator pump?

- I thought there was maybe an air problem preventing flow so I was looking for valves near the boiler. I tried turning what looked like a little knob on top of a cylindar shaped copper device, located directly above the expansion tank. The knob didn't turn and water started spraying out of the copper seam on top. Is this a crisis?

- What are the consequences of running the boiler for short periods with the circulator pump not working?

- Should I be able to replace the pump without draining the system?

- I found what I think is the manual for my boiler online. It says that when filling the system (cold) the pressure should be 10 to 15 psi. But mine is reading about 22 psi. Is this another crisis? .. It was around 30 psi during the hour or so I had the boiler running, which I think is correct. But i seem to remember doing a test last year when it exceeded 30.

- I have attempted some pretty radical JB Weld repairs. But I think I'll make that a seperate post, with pictures.

.. I'm reluctant to hire a professional at this point because it is quite a mess and not really a very professional situation until I get some replacement radiators in here. I foresee high expenses, slow progress, compromising results and frustration on both sides. Plus most contractors in these parts wouldn't even consider preserving a radiant system.

I think I have a pretty good handle on managing the plumbing and freezing temps etc, and that most of the risk involved is to do with potential property damage, rather than safety. But I would like to know what the potentially hazardous conditions might be. What would cause a boiler to explode?

Thanks for reading and for any replies. Feel free to give general advise or to answer which ever questions you like. I will be actively checking in.

BobC

Take some good pictures of a radiator so we can see how ot's built. Some types of radiators can be taken apart and some can not. Have you checked into used radiators in your area?

Bob

gliptitude

Thanks for the reply Bob.

Attached is one photo of one cracked radiator. Not the best photo, but one i already had on my computer. You can at least see that it has the rods going through. They do have nuts on the end as well. .. I have various sizes and styles throughout my house, but all have the rods going through.

The one radiator here that i completely demoed had unthreaded metal (gaskets?) inbetween each fin connection.

Jamie Hall

Seems to me the title here is a little misleading -- I think that you are describing a hydronic heating system, rather than a radiant system? Radiant would have long runs of pipe looping through the floors (or sometimes walls or ceilings) but you are speaking about radiators...

Which wouldn't be a problem, except that some folks might not read the thread, not realising what it is really about!

Some easy questions -- running the boiler for very short periods of time without the circulator running might not be a problem. Not a good idea, though, if you can possibly help it.

Unions should not need any kind of sealant. In fact, the surfaces of the union should be very smooth and clean. One does, however, have to make sure that the union is mating properly; they won't take up any angular or horizontal displacement to speak of. It sometimes helps to rock the radiator very very slightly while taking up the union.

I doubt very much that you'll be able to replace the pump without draining the system, unless the pump has isolation valves on both sides. Some do, some don't.

This is a one story structure? In that case, 15 psi should be ample pressure. 22 psi is OK, perhaps. At 30 psi the pressure relief valve on the boiler should open -- if it doesn't, you have a problem with that valve.

Depending on how the system is piped, it may be possible to supplement some of the threaded pipe with PEX. But we don't know how it's piped, and that's critical.

Last comment (for now): where are you located? I rather think that a really competent professional is probably going to be needed, and better sooner than later. I'm puzzled by your comment that most contractors in your parts wouldn't even consider preserving a hydronic system; they are, after all, pretty common. At any rate, it is possible that we may be able to recommend someone if we know where you are (or you could try "Find a Contractor" in the menu -- search by state).

gliptitude

Jaime, maybe my lingo needs to be straightened out. I thought "radiant" referred to all types of steam and water systems, that "radiant" refers to the method of conveying heat, which is common among them. At any rate, yes I have hydronic with cast iron radiators. No in-floor heating.

The house is TWO stories tall. The first floor is about double the area of the second floor. The basement is the same as the second floor. Half of the first floor has basement underneath and the other half has crawl space.

"How the system is piped"? Well there is a supply circuit and a return circuit. Each radiator taps into return on one side and supply on the other. All radiators sit on the floor and all supply/return connections are at the lower portions of the radiators. There is no manifold like. It looks like the supply line splits into two main branches and that the cold radiators were both on one and the warm ones were together on the other.

Again, I was very confused that the hottest radiator was on the second floor. The one directly below it on the first floor was only warm.

The circulator is on the supply line, very close to the boiler. It looks like the city line goes into the return line, also close to the boiler.

The circulator does not have shut offs on both sides but there is one on one side and then there is another, (see pics) on the return line, near the boiler. .. I'm guessing if I close both of these only a small amount of water will come out at the beginning of circulator removal?

I'm kind of hoping for an exact replacement so that I don't have to redo the piping. But I've heard that there are better products for efficiency and different/better methods of locating the circulator.

.. I live in Cincinnati, Ohio. I have consulted with a professional installer (a family member) and he has been here a couple times, but he is generally unavailable. .. Given the condition of my radiators and the age of the boiler, he advises that a new forced air furnace and duct install would be less expensive than bringing my current system up to date and fully operational.

.. Hydronic, steam and radiant systems still exist here, but they are less common than in some other parts of the country. I have never heard of a new install in a single family home, certainly not in new construction, (excepting maybe in-floor heating as a supplemental system).

gliptitude

Some better pictures of the radiators..

Jamie Hall

Well, you certainly are right about hydronic and steam and radiant being a little unusual in new installs, for the simple reasons that first there aren't all that many people out there who can do it right and second they are -- on new installs -- more expensive than scorched air. They are also much more satisfactory, but that's a hard sell.

Cracked radiators are much more of a problem on hydronic -- which you have -- than on steam, simply because of the much higher pressures on hydronic. It may be that your JB Weld patches will hold. One can hope.

The odds are that the bleeder valves on the radiators (I love the improvised bucket!) were damaged by freezing. They can be replaced, with care and patience (you don't want to bust them off in the radiator...).

At a first guess, the uneven heat may be simply from radiators being air bound. Each one needs to be bled separately. This sometimes shows up as a radiator which is a good deal warmer at the bottom than at the top, but that isn't a guaranteed sign.

The 15 psi static pressure should be enough for two stories, though I'd be happier at 20 psi static. When the boiler fires, the pressure might rise some -- a few pounds. It shouldn't rise more than that. If it does, the chances are that the expansion tank is waterlogged and probably should be replaced.

SWEI

You appear to have a gravity hot water system which was added on to (or reconfigured) at some point with smaller pipes on some radiators. This can throw off the room balance, especially if the system is overpumped.

Do you have any photos of inlet and valves from one the older radiators (the ones with the large pipes connected to them)?

Gordy

Your system appears to be a converted gravity. At one time there was not a circulator, and the piping which was much bigger to the boiler (which was a different boiler).

So now your trying to use it with out the circulator, and smaller piping off the boiler. That won't work very well. The piping to the boiler is smaller, and the in line circulator diminishes flow. So that is part of your issue.

you really need to replace rads that were damaged, and do some better permanent repairs on the rest of the damaged portions of the system.

gliptitude

SWEI said:

You appear to have a gravity hot water system which was added on to (or reconfigured) at some point with smaller pipes on some radiators. This can throw off the room balance, especially if the system is overpumped.

Do you have any photos of inlet and valves from one the older radiators (the ones with the large pipes connected to them)?

I think all of the radiators I have shown so far have identical pipe sizes, maybe 1" or 1 1/4". The ones upstairs (not in photos) have smaller piping, maybe 3/4".

The new pictures in this post are of another radiator on the first floor which has slightly larger pipes than the others.

I'm not sure if I've photographed what you were asking for or not.

.. I'm pretty sure that my cold radiators were NOT on their way to getting warm. I had the boiler running for about an hour and even the big pipe in the basement was cold.

gliptitude

I forgot to attach these photos to the previous post:

gliptitude

Jamie Hall said:

...

The odds are that the bleeder valves on the radiators (I love the improvised bucket!) were damaged by freezing. They can be replaced, with care and patience (you don't want to bust them off in the radiator...).

At a first guess, the uneven heat may be simply from radiators being air bound. Each one needs to be bled separately. This sometimes shows up as a radiator which is a good deal warmer at the bottom than at the top, but that isn't a guaranteed sign.

The 15 psi static pressure should be enough for two stories, though I'd be happier at 20 psi static. When the boiler fires, the pressure might rise some -- a few pounds. It shouldn't rise more than that. If it does, the chances are that the expansion tank is waterlogged and probably should be replaced.

I easily unscrewed the bleeder valve (with a wrench) from the radiator that I demoed. I also have a small bathroom radiator that I bought salvaged. It had a bleeder valve that I couldn't get to open so I easily unscrewed that and easily screwed in the one I had taken off the demoed radiator. .. Is that all there is to it? No pipe sealant or anything?

...

What does "air bound" mean? .. I don't think uneven heat really describes what I observed. Two of the radiators did not seem to be getting ANY heat. And the bigger pipe they branch off of in the basement was also not heating up.

...

I haven't thought to be concerned with too little pressure. I was afraid I had too much pressure. I think my boiler specs 10 to 15 static and 30 in operation. I don't know what is causing this and I don't know what the consequences for running higher are.

When my HVAC family member was helping me with it last year we removed a device, i think from the city line. He could not identify this device or it's intended function, but it was entirely preventing the flow of water. We simply eliminated it and replaced with pipe. .. I brought it to a local radiator supply shop and they were also unable to identify it. .. Perhaps it was a pressure reducer of some kind?

I think the dome shaped device above the expansion tank is supposed to regulate pressure but I seem to remember my uncle saying it was not fully functional, maybe that you are supposed to be able to recalibrate it but that the adjustable part is not mechanically operable anymore?

gliptitude

Gordy said:

So now your trying to use it with out the circulator, and smaller piping off the boiler. That won't work very well. The piping to the boiler is smaller, and the in line circulator diminishes flow. So that is part of your issue.

you really need to replace rads that were damaged, and do some better permanent repairs on the rest of the damaged portions of the system.

I understand that replacing all of the broken radiators is the only proper solution. But that will be very difficult for me to do and very expensive for someone else to do. In the meantime I am trying to get an overall evaluation and understanding of the system, if it is feasible to commit to or not. .. For immediate heating purposes, it would be very useful having the three non-broken radiators working. I just don't know if there are potential problems or risks to the system having such a small number of radiators?

I don't expect to run this system for heating purposes without the circulator operating. I only ran the boiler for about an hour, and I determined that the system had too many problems to let it continue running. But I was curious what the risk involved was, if running without the circulator working (for short periods of time, 30 to 90 minutes) was potentially damaging to other parts of the system, or if this could cause the circulator to burst or something. The circulator was very hot.

ratio

Is the circ still trying to run? If you can hear or feel a humming or buzzing in the motor, it still has power applied. If it's unable to turn it should be switched off. Follow the wire back & see if you can find a cutoff switch. Another test would be if the motor is hotter than the inlet & outlet pipes.

If the system is converted gravity, I wouldn't be surprised by the top radiator heating first, or even only. There would have been orifice plates in the higher radiators to balance the gravity flows, a pumped conversion would have moved those to the radiators closer to the pump - generally the lower ones...

If there's a radiator getting hot, we're definitely moving water. Maybe the pros will chime in, but if it were my system, I'd run it & watch the temps & pressure for a few hours & see what it does. If the supply doesn't get crazy hot (don't want to make steam), the return warms up (thermal shock & condensing), & the pressure doesn't get high enough to open the relief, I'd let it run. It'd be working pretty closely to how it was originally intended to run!

Jamie Hall

Well let's see here. First off, 30 minutes is NOT what I would call brief when running a hot water boiler without the circulator running. 30 seconds maybe.

So... may I respectfully suggest that before you try to run it again, you replace the temperature and pressure relief valve with a new one, calibrated for the ratings of your boiler, and piped correctly. This will reduce the possibility of very loud noises in the basement.

The unknown contraption on the supply line from the domestic water to the boiler may have been a pressure reducing valve. It may also have been a backflow preventor. You should have both (most codes require them). The pressure reducing valve should, in your application, be set to 15 to 20 psi, no more than that.

The system pressure, running, should never rise above 25 psi. If it does, and the static pressure (system cold) is where it should be -- not over 20 psi -- the expansion tank is either waterlogged or shot or both, and needs to be replaced. It should be piped to join the system close to the inlet side of the circulating pump.

Gordy

There are built in safety features on your boiler.

The relief valve usually 30psi. That's why your system pressure set when cold should be 15 psi in your case.

An aquastat which sets the high, and low temperature your boilers burner will turn off, and back on at. Usuall low is 135-140, and high 180 with cast iron rads..... For now.

Before the burner lights a chain of events have to happen ( proving).

The circulator turns on.
The damper opens.
The spill switch is not open.
The roll out switch is not open.
Then the gas valve opens, and hopefully lights. If not after a short period gas valve closes.

Are you sure the circulator is not functioning? If so how was it determined?


The problem with running with out the circulator functioning is the boiler will heat up very fast,. It should cycle the burner off at the determined high limit IF everything is working properly.

gliptitude

Gordy, I am not certain the circulator is not functioning but I believe it to be the case. These are the reasons:

- There is a history of the circulator not circulating: a professional determined that the circulator was not running last year. He removed the circulator, opened it and cleaned the element or loosened it to help it spin. Reinstalled and could HEAR the circulator running.

- i can't hear the circulator running.

- some of the connected radiators and pipes do not seem to be heating up at all.

.. I don't think there is any problem with the controls or power supply to the circulator, so maybe the boiler is passing it's checks fine even though the circulator is not actually circulating?

.. My 22 psi static is high. But this is much lower than the supplied pressure of water in the house correct? So there must still be something effecting a pressure reduction, just not enough, correct?

This is the mystery device we removed last year. I think it was on the city line, near the expansion tank:


[IMG]http://i63.tinypic.com/348n6hd.jpg[/IMG]

[IMG]http://i66.tinypic.com/6hm62q.jpg[/IMG]

[IMG]http://i65.tinypic.com/2d10oeb.jpg[/IMG]

...

The boiler seemed to fire up fine and at no point behaved in any way that surprised me. The damper definitely opened. Some pipes heated and others did not. The only excessive heat that I noticed was on the circulator itself. It was hotter than the hot pipes. The flu pipe was hot, but that is normal I think.

I have to review the manual. I thought that the tasks of pressure regulation were external to the boiler.

gliptitude

Jamie Hall said:

Well let's see here. First off, 30 minutes is NOT what I would call brief when running a hot water boiler without the circulator running. 30 seconds maybe.

Okay.

Jamie Hall said:

So... may I respectfully suggest that before you try to run it again, you replace the temperature and pressure relief valve with a new one, calibrated for the ratings of your boiler, and piped correctly. This will reduce the possibility of very loud noises in the basement.

I will look into this. .. Your suggestions are quite welcome. I consider myself very lucky to be getting professional advice with this and I'm trying not to scare you guys off or offend anyone.

Jamie Hall said:

-- the expansion tank is either waterlogged or shot or both, and needs to be replaced. It should be piped to join the system close to the inlet side of the circulating pump.

I suppose this is one of the easiest and least expensive parts to replace so I might as well just do it?

Currently the expansion tank hangs off the city line, shortly before the city line enters the radiator return line. The circulator is on the radiator supply line, right at the beginning out of the boiler. .. Does this current setup conflict with what you are recommending?

.. My previous post links photos of the mystery device we removed last year.

Jamie Hall

There must be a pressure reducing valve between your city water and your boiler. The mystery device may have been it. Whatever, you have to have it, and should go out an get one installed. Set it for 15 psi, or half of whatever the nice new relief valve you have is set for. There should also be a reduced pressure zone backflow preventor in line between the city water and your boiler; some codes require it and I wouldn't have a system without it, code or no code.

Your current piping arrangement really isn't that good. The expansion tank should be piped in after the boiler and before the inlet to the circulator.

Sounds to me as though the circulator is not working properly, if at all...

SWEI

gliptitude said:

a professional determined that the circulator was not running last year. He removed the circulator, opened it and cleaned the element or loosened it to help it spin. Reinstalled and could HEAR the circulator running.

- i can't hear the circulator running.

Cleaning or freeing up a stuck impeller is not likely to result in a permanent fix. Depending on the fluid quality and the age of the circ, you my be due for a replacement.

gliptitude

Well i have drained the system. I think I have some idea of where to start now and what i need to study up on.

The discussion has narrowed down to the mechanical stuff in and around the boiler. So i think the radiator repairs/replacement is a different subject at this point. I'll probably post separately on that. I'll be referring back to suggestions made and hopefully figuring some things out and posting progress or new/better informed questions here.

Thanks for all the input.

gliptitude

Progress report:

- I replaced the circulator - Taco exact replacement 007 F5

- Replaced the device that i broke which was an air vent (see attached photo of old and new)

- Determined that i incorrectly described piping around boiler. Circulator is on return, not supply. I think the piping is not what we now consider ideal, but it is not ridiculous and it looks like what used to be standard.

- Identified pressure regulator, adjusted with fill running and observed apparent change in pressure, (did not measure but could hear flow changing). Learned at the supply shop that this device is what is primarily responsible for controlling the static pressure of the system. Rather than replace this (was considering because i was getting 22 psi static) i will try to adjust it after fill.

- Identified pressure/temperature relief valve. This is on the boiler. Cannot be tested until system is full and hot.

- brought the expansion tank into the radiator shop. It appears to have charge and not be water logged and they told me to put it back on and gauge my other repairs before i buy a new tank.

- Figured out where a backflow preventer would go and what they cost, that they are required now but were not in the past, that this is exclusively a water quality issue rather than an immediate hazard. .. Am putting this off for the time being.

- did a few more things to the radiators but i won't go into that.

..........

So i plan to fill the system and fire up the boiler again tomorrow...

gliptitude

New circulator seems to work and all radiators warmed. I got the static pressure down around 14psi, but I'm not certain that the way I did this was kosher. Also operating pressure seemed a bit low, maybe about 22 psi. .. I only ran the boiler for about 40 minutes, which was not long enough to reach room thermostat temperature level.

I have two pretty critical questions:

- Is it normal for the circulator to get hot? It was hotter than the (return) pipe that it is on.

- I adjusted the pressure regulator by turning the bolt on top, however this did not immediately correspond with a change in pressure as indicated on the boiler. After adjusting, I drained a bit of water from the boiler and the indicated pressure did go down. I could not hear fill water running to replace the drained water. I pressed on the fill lever on the pressure regulator and the water did run a bit, but pressure remained stable. .. Does this sound fine, or is there a better time in the sequence of things to adjust the pressure regulator?

Gordy

System pressure should be set while the system is at ambient temperature. If you have a bladder, or diaphragm expansion tank. It's pressure should be adjusted to the desired system pressure isolated from the system.

If you have a tank that is hung up in the floor joists then you fill the system to the desired psi. Again when system is at ambient.

The pressure reducing valves function is to maintain the desired fill pressure. There is an adjustment on top to set it. Once set leave it alone. There is also a fast fill lever on the PRV to over ride this setting to fill a system that needs a lot of water.

The circulator will get very warm. If it's on the supply piping it will eventually get as hot as the supply piping temperature.

gliptitude

Thanks for the reply Gordy. Can you please clarify a bit?

Gordy said:

System pressure should be set while the system is at ambient temperature. If you have a bladder, or diaphragm expansion tank. It's pressure should be adjusted to the desired system pressure isolated from the system.

...

The pressure reducing valves function is to maintain the desired fill pressure. There is an adjustment on top to set it. Once set leave it alone. There is also a fast fill lever on the PRV to over ride this setting to fill a system that needs a lot of water.

I had removed the expansion tank and added some air, to 12 psi.

.. I understood how to adjust the PRV, and did so at ambient temperature. The problem is that this did not correspond with a change in pressure, until I subsequently drained some water from the system.

.. Is that just because I had already allowed the system to fill at the previous PRV setting? .. Isn't the PRV meant to allow new water in at any time that it is needed? Therefor draining some water off to achieve proper (lower) pressure like I did is ok right?

I guess my real original question was "how do I accurately gauge the adjustments I make on the PRV?"
It looks like I have to completely fill before I can actually determine what the PRV is set at.

Gordy said:

The circulator will get very warm. If it's on the supply piping it will eventually get as hot as the supply piping temperature.

The circulator is on the return and it got at least as hot as the supply pipes.

Mark Eatherton

Here's a simple test method for determining wether or not the circulator is running and moving water when you don't have a ball valve that you can quickly close and hear the HISSSss of a close off..

With the boiler cold, and the burner in the pilot position, make a call for heat.

Take a torch (flame type, not light type) and hold it on one spot on the return pipe for 10 seconds. Shut off the flame, and count to 10 seconds. CAREFULLY touch the same spot you'd heated. If it is still hot to the touch, you have no circulation. If it is cold, you have circulation.

To test the fill valve, again as Gory stated, with the system cold, not hot. Drain some water from the boiler until you hear the make up valve feeding water. Close drain and observe final fill pressure. You really only need 1/2 PSI per system elevation above the gage, plus 5 PSI.

The 007 normally runs 40 degrees F above ambient, or the fluid, whichever is greater. Expect it to be hot. You really can't use an amprobe to test it for lock up, because these low impedance motors draw the same amps when running as they do with a locked rotor.

ME

gliptitude

Thank you Mark. That seams very clear.