fitting upgrades & additions for an old cast iron rad hydronic system?

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Old 12-13-13, 04:08 PM
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fitting upgrades & additions for an old cast iron rad hydronic system?

Hey there. A few questions for anyone out there willing to lend some advice; I apologize in advance for the length of this post!

I've got a rental house in Ontario, where the outside temps have already been colder than -30 Celsius this year and the heating system has been giving my tenants some issues over the past little while, so I'm hoping to help them out as best I can from many provinces away. An attempt at sending a couple of the local plumbers/HVAC guys over there hasn't really fixed anything, as everything was working fine once they got there, so I'm hoping for a bit more insight here.

The biggest issue they're having is that 2 or 3 of the rads are rarely heating up at all. These rads are all on the same wall of the house (front side, or opposite side of where the boiler's installed; not sure if that matters) and they're on both the main and 2nd floors. The rest of the rads in the house are working fine. I've never taken a close look at the different routes that the heat is pumped up to, but I'd imagine these are all on either the last loop, or there's something blocking them from working properly (dirt/crap/air lock).

The boiler room is apparently quite hot as of last night, and it sounds like the safety relief valve on the boiler manifold has been relieving itself more than it ever should be. Pressure seems to always be climbing to nearly 30psi, when it lets go. Upstairs, the thermostat has a call for heat of 74 F, yet the actual temperature still reads 66 F or so and doesn't get any warmer than that (maybe 2 or 3 days now?). According to my father who stopped in to see if he could fix anything, the Schrader valve on the expansion tank would leak a dark brown bit of goo if he tried opening the valve for a quick second. I don't know if that's sludge in the system or the diaphragm in the expansion tank disintegrating, but he said the tank sounds like it's full of water (diaphragm not diaphragm'ing).

The boiler (a 4yr old Buderus GB-142), has pretty much been running flawlessly over the past few years, with the exception of tweaking it at the start to operate smoothly. It is heating a number of ancient cast iron rads from the basement, going up 3 stories. Two rads up in the top loft, four rads on each exterior wall of the 2nd floor, and four rads on the main floor. Pretty sure my expansion tank (Extrol 30) has kicked the bucket, so I'm ordering a new one (an Extrol 60, as I think my boiler is sized between the 2 suggested expansion tank capacities, so I figure a larger one couldn't hurt).


I'm also curious about a couple other things though.

I have no in-line dirt/particulate filter in the system, and haven't since I bought the house, but the more I learn about these systems, the more I think it's foolish that there was never one installed when I replaced the old boiler 4 years ago. I've drained the entire system a couple times since then, mostly to get some lines changed around, and added an inhibitor solution both times. Apart from that, it's been a mostly closed system (aside from letting city water into the system on an automatic fill valve).

I have read a lot lately about this Fernox TF1 filter system that seems to be big in Europe, but not at all across the pond.

TF1 Total Filter

Does anyone have any experience with these? Any comparisons between the Fernox and something like a SpiroTrap dirt separator? The Fernox looks like it can handle a lot more crud if need be than the SpiroTrap.

I also don't believe there's ever been an air eliminator anywhere in the system. It's always operated fairly well, and I was quite a newbie when it came to hydronic heating when I bought the house. The only spots in the system to eliminate air automatically, as far as I can remember, are in the top loft, where I have a Watts automatic air vent on each of the 2 rads up there.

I'm assuming installing something like a SpiroVent on the supply side of the boiler would be the norm?


Anyway, thanks to anyone that made it through this series of questions. If you have any advice, I'm all ears.
 
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Old 12-13-13, 04:35 PM
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relief valve on the boiler manifold has been relieving itself more than it ever should be
Which happens to be ONCE. That one time is more than it ever should be.

Pressure seems to always be climbing to nearly 30psi, when it lets go
There are only three things that can cause this, in order of likliehood:

1. Expansion tank low on air or just plain defective.

2. Pressure reducing valve 'leaking through' and slowly feeding water to the boiler, ultimately over pressurizing it.

3. If the boiler is fitted with a domestic hot water coil, that coil could be leaking into the boiler and causing same issue as #2.

Or any combination of the above.

I didn't put this on the list... there is actually a 4th possibility that the tank is too small for the system.

the Schrader valve on the expansion tank would leak a dark brown bit of goo if he tried opening the valve for a quick second
This plays to #1 above.

Whatever the stuff is, it's clear evidence that the tank needs replaced.

So, it's clear that at least one of the orders of business is to get that tank changed.
 
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Old 12-13-13, 04:46 PM
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going up 3 stories
There's something here that you need to be aware of...

The MINIMUM PRESSURE when the system is COLD needs to be HIGHER than the standard 12-15 PSI because of the extra height of the third story. 12-15 PSI is only good for homes of 2 stories or less.

You probably need to maintain at LEAST 17-18 PSI COLD on the system.

so I'm ordering a new one (an Extrol 60
Sounds like a wise choice. A 3 story home with cast iron rads has a LARGE water capacity and it is very likely that the 30 was too small.

Be aware that when you raise the cold fill pressure of the boiler that the expansion tank air charge must be raised to equal that cold fill.

Please read this:

http://www.doityourself.com/forum/bo...sion-tank.html

There's good info for you to help your understanding...
 
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Old 12-13-13, 05:05 PM
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Fernox TF1 filter system...Does anyone have any experience with these?
I sure don't. I'm not uber-familiar with the Buderus boilers and don't know how 'tight' their heat exchangers are, but if they are tight, and you suspect there's a lot of 'crud' in your system, I suppose it's something to consider.

I would think the SpiroTrap would do basically the same thing... easier to obtain here in the states.

I also don't believe there's ever been an air eliminator anywhere in the system
Yeah... well... that ain't right.

The only spots in the system to eliminate air automatically, as far as I can remember, are in the top loft, where I have a Watts automatic air vent on each of the 2 rads up there.
And that's just wrong.

Placing an automatic float type air vent at the TOP of a system is a recipe for SUCKING AIR INTO the system.

System pressure at the TOP of a system is WAY less than at the bottom.

This goes back to the 17-18 PSI MINIMUM I mentioned previously.

Let's do some physics, shall we?

To raise water in a column ONE FOOT high requires 0.432 PSI of pressure. Let's say that from the boiler in the basement to the tippy-top of the system you have 32 feet of 'altitude'.

32' X 0.432 PSI = 13.82 PSI

This means that just to get water to the top of the system you need at least 13.82 PSI.

If the pressure at the boiler EVER falls below this, the pressure at the top of the system becomes SUB-atmospheric and this means that those vents will SUCK AIR INTO the system when that happens.

The reason that I said you need 17-18 PSI for a three story system is because we take that 13.82 PSI, round it up to the nearest PSI and ADD FOUR MORE PSI to that number... voila! 18 PSI!

The extra 4 PSI is 'insurance' or 'headroom' to guarantee that there is always PRESSURE at the top of the system.

You can leave those vents in place for service work, but CLOSE THE CAPS TIGHT when in normal operation.

There's more...
 
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Old 12-13-13, 05:22 PM
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Let's talk about how your boiler is actually piped into the system... are you familiar with it's setup?

Do you know if the installers piped it in what we call a "PRIMARY/SECONDARY" setup?

If not, it probably should have been.

Do you know if the system pump is PUMPING AWAY from the "Point Of No Pressure Change" (PONPC)?

Some points of information:

TWO types of pressure exist in a heating system:

1. STATIC PRESSURE - is the pressure in the system when no water is moving. The FILL pressure.

2. DYNAMIC PRESSURE - is the pressure in the system when the pump is running and moving water. Dynamic pressure can be HIGHER OR LOWER than the static pressure depending on how the system is piped.

In any heating system, there is what is known as the PONPC, and this point happens to be the point at which the expansion tank is connected to the system.

A circulator pump moves water through a system by creating a pressure difference between the SUCTION and the DISCHARGE side of the pump. This difference in pressure is called "PUMP HEAD". The PUMP HEAD is what contributes to the DYNAMIC PRESSURE in the system.

As water is pumped through a system, friction of the water against the piping and accessories creates a PRESSURE LOSS, or "SYSTEM HEAD".

"HEAD" in a system can be expressed either in FEET or in PSI, and the numbers are directly proportional to each other. Remember that 0.432 PSI per FOOT mentioned earlier? ONE FOOT of HEAD = 0.432 PSI and ONE PSI of HEAD = 2.31 FEET of HEAD (it's the inverse)

Pressure is lost along the path of water flow because of this system head.

So, let's put this into perspective...

Let's say that the PUMP HEAD is 5 PSI when the pump is running.

Let's place this pump in the system and have it pumping TOWARD the expansion tank connection which happens to be the PONPC. Since the pressure can not change at the PONPC, this means that the 5 PSI of PUMP HEAD will be SUBTRACTED from the STATIC PRESSURE in the system.

By pumping AWAY from the PONPC, the pump head is ADDED TO the Static pressure in the system.

OK, that's a whole lotta BS, ain't it?

What's it mean in real life? .. next...
 
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Old 12-13-13, 05:28 PM
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What it all means it that:

If your system is pumping TOWARD the PONPC, when the pump runs, you will have LESS PRESSURE at the top of the system. This is yet another reason to ADD 4 PSI to the static pressure. You don't want the pressure at the top of the system to drop sub-atmospheric at any time, even if you do NOT have automatic air vents up there. This is because it will cause any air dissolved in the water to come out of solution and form air bubbles which will create noise, can block flow, and reduce heat transfer area.

If you pump AWAY from the PONPC, pressure is INCREASED throughout the system when the pump runs. Never any concern with sub-atmospheric pressure at the top of the system creating problems... and, any air bubbles that DO exist are squeezed SMALLER and are easier to move through the system.

There is a definite advantage to pumping away from the PONPC.

Whew! that was a lot to think about, wasn't it?

If you've bothered to get this far, let me know, and then we'll talk about what the problems with your system might actually be...
 
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Old 12-13-13, 05:29 PM
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Thanks for your replies. The expansion tank is in the cart, waiting to be ordered; just trying to see what else I might need, eg. the air eliminator, and any other ball valves that I clearly need to add to help isolate some of this stuff. The guy who installed my boiler seemed like a bit of a hack, which is unfortunate because I chose him because of glowing reviews from friends of mine. Anyway, he left me with a bit of a mess that I've been slowly trying to figure out since.

But yes, hoping to have most of this hardware on hand by early next week.

As for the air vents up top, that's what the guy who installed my boiler did a few weeks after it was installed, when the system wasn't operating efficiently. He installed one on each of the topmost rads, had them a few threads unscrewed when bleeding the system at the beginning of the season, and we have them closed otherwise. That has seemed to work well, otherwise. Even if those are a turn or 2 opened, are they not designed to prevent backflow (of air/water), or do they just receive and purge air in one direction?

I usually keep 18-20psi in the system, as I agree with what you said about extra headroom, and it's had around 19psi since I have owned the house (with the original boiler too).

As a side note, I'm learning about all this sort of stuff in school right now, so I'm getting a bit more of an understanding, and I'm growing less confident with the HVAC guys in that city who claim to never find anything wrong with the piping arrangment, or the problems.

Thanks again!!
 
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Old 12-13-13, 05:31 PM
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I'm assuming installing something like a SpiroVent on the supply side of the boiler would be the norm?
I don't think that would be the norm. I would venture to say that MOST SYSTEMS in use today are NOT set up properly, at least according to "new school" teaching.

"Old School" could have the air scoop and air vent anywhere... return, supply, whatever... wherever it fit is where it went... and the pump was usually on the return side, pumping into the boiler.
 
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Old 12-13-13, 05:36 PM
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Even if those are a turn or 2 opened, are they not designed to prevent backflow (of air/water), or do they just receive and purge air in one direction?
No, the design will not prevent backflow of air. Inside that can is a 'float'. When the can gets air inside, the float drops and opens the 'needle valve' to let the air out. When there is pressure in the system the air that is let out allows room for water to take it's place, pushing the float back up and closing the valve.

There's nothing stopping lower pressure inside that can from pulling the water down along with the float, opening the needle valve and sucking air IN.
 
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Old 12-13-13, 05:37 PM
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I usually keep 18-20psi in the system, as I agree with what you said about extra headroom, and it's had around 19psi since I have owned the house (with the original boiler too).
Great!

As a side note, I'm learning about all this sort of stuff in school right now, so I'm getting a bit more of an understanding, and I'm growing less confident with the HVAC guys in that city who claim to never find anything wrong with the piping arrangment, or the problems.
I think that's fantastic! Spiral out, keep going! Never stop expanding!
 
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Old 12-13-13, 05:38 PM
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Your replies are too quick for me to keep up! Hah. I'm not sure which direction things are flowing with regard to the expansion tank, but you're probably right, it could be backwards. It's been a while since I was down in that boiler room looking at the boiler. I asked my father to take a couple pictures of the whole setup, so I know what we're dealing with.

This system is far too finicky for most, but I'm really interested in hydronic heating, so luckily I've got enough patience to trek through the issues. I just wish I could be at the house doing the troubleshooting, and not having to use my father as the middle man. He's got a pretty solid understanding of the piping, but he knows about as much as me when it comes to pressure levels, headroom, etc. (minimal to a bit more than most people).

Wondering why the boiler installer thought that installing something that could potentially suck air back into the rads would be a good idea....he had made it sound like an ideal system (for an older setup like mine) would have one or 2 automatic air vents on every floor.
 
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Old 12-13-13, 05:43 PM
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I asked my father to take a couple pictures of the whole setup, so I know what we're dealing with.
When he sends them to you, please post here so we can better make suggestions.
 
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Old 12-13-13, 05:48 PM
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Wondering why the boiler installer thought that installing something that could potentially suck air back into the rads would be a good idea....he had made it sound like an ideal system (for an older setup like mine) would have one or 2 automatic air vents on every floor.
I'm going to be nice... and not insult him... or try not to...

Not many people REALLY understand this stuff, or give it much thought. My guess is that he's never even HEARD OF the 'pumping away' concept, and if he HAS heard of it, he probably doesn't understand what it really means.

Is saying someone is ignorant an insult? Ignorant just means he doesn't know something right? Not like I'm calling him stupid, or unintelligent, right? Not like I'm saying that he couldn't learn if he were motivated to...
 
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Old 12-13-13, 05:53 PM
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Sounds good. Another question for you, since you clearly know what you're talking about....

The original control valves on a couple of the radiators seem to be stuck fully open (better than fully closed!). If at all possible, I'd like to change them all out, as one or 2 have a dribble of water once in a while as well. I could probably leave the other ones, but if half of them need service or replacing anyway, I might as well try and buy 10 valves at some sort of bulk discount.

Would a thermostatic rad valve be worthwhile or even feasible (versus a standard valve) in this system of mine? The rads only have one valve on them (I've seen others that have both an inlet/outlet valve?). They're all old cast iron radiators, so I'm not sure if I could find valves that would need to thread into them, or install some kind of bushing or reducer to make it work?

I have no idea what size fittings are on this system, as I've never messed around with any of the valves actually attached to the radiators.
 
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Old 12-13-13, 06:06 PM
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Also are powerflushes done often on this side of the ocean as well? I can't help but think my system in that house needs a good cleansing.
 
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Old 12-14-13, 08:49 AM
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I'd like to change them all out, as one or 2 have a dribble of water once in a while as well
They might simply need to have the valve stem packing replaced. At what point on the valve is it leaking? Around the valve stem?

Would a thermostatic rad valve be worthwhile or even feasible
Whether or not you can use TRV depends on how the radiators are piped. While it's not highly likely that they are in a 'series loop', it is possible. If they are, you can't use TRV or even close the valves because flow will stop to all rads in the loop.

If they are all 'home runs' to a manifold by the boiler, you can.

If they are on monoflo(TM) tees, you can, but it may still be somewhat of a problem because you really shouldn't close a monoflo side loop... it creates a restriction in the main flow and can starve the flow to the downstream rads.

THREE WAY TRVs USED TO BE available, but all my searches on the net lately haven't turned any up. With a 3 way valve, when the supply to the rad is cut off, the flow is diverted around the rad and downstream rads will still have flow.

are powerflushes done often on this side of the ocean as well?
Often? No, I don't think so. You might end up creating more problems I would think by 'stirring up' any sediment that might be laying around... that's probably something that needs a lot of thought before attempting. Depending again on how the system is piped, it might be difficult to achieve any useful results from the attempt.

We need to know a LOT more about your system.
 
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Old 12-14-13, 09:29 AM
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a couple leak sometimes around the valve stem, and a couple leak from somewhere near the unions i think (not positive).

i believe there are 2 or 3 loops in the system. would that make sense? my tenant told me at one point she didn't want to throttle any of the valves because one of the larger rads' valve would leak when she closed it at all.

at this point i'm in near desperation-mode, and don't really care too much about valves on the rads, unless they're blocking flow.

it's been colder than -20 for the past few days, and they're getting nervous at the house (me as well). my father's at the house now, snapping a couple pictures. he had said one of the main risers going upstairs to one section of the house is super hot for a bit of a run, then gets cold fairly quickly, and every other pipe that is teed off from that main cold pipe is obviously cold. some blockage in the line?

not even sure the of the best way to deal with it, since there are not many (any) places to isolate the boiler system apart from right at the boiler manifold itself. i'm worried that draining the system, with hopes to flush whatever crud out of there will leave me with a cold house if things don't re-fill properly.

any suggestions at this point? my dad's working on sending me these pictures in the next little bit.
 
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Old 12-14-13, 11:50 AM
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here's a mess of photos for you.


boiler with manifold
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that condensate discharge cup isn't collecting under the discharge drain from boiler any more, and it's leaking onto the piping. i'll need to get that better attached. also, the garden hose is on that safety relief valve as of this morning to drain into a sump pit until we can figure this stuff out (pretty sure having a hose on there isn't to code). also, notice the supply and return lines, with their own circ pump to the indirect hot water heater.
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automatic fill valve on the top
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notice the goo. sludge?
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Old 12-14-13, 11:57 AM
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a couple more...

the goo was coming from the top of this air vent. is that amtrol air purger all i need? does it do the same thing as a spirovent?
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this is how the piping arrangement looks for that manifold.
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Old 12-14-13, 01:21 PM
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Jeff, Have I asked if this system ever worked properly yet? If not, has it?


First thing... WHERE IS THE SYSTEM PUMP? There MUST be another pump! If there is not another pump, that's a huge problem, you will have no circulation in the SYSTEM.


IMHO, the installers should have used MUCH LARGER pipe to connect to the existing radiator piping. It appears they've used 1" when in fact I feel it should have been AT LEAST 1-1/4" to get the flow that will be needed for all those rads and that large piping. In fact, 1-1/2" probably would not have been too large.


That black goo is coming out of the AIR VENT? WTH IS UP WITH THAT? It was bad enough when I thought it was coming out of the tank... but the vent?



You've got something VERY out of the ordinary going on there with that 'resin' or whatever it is coming out.



Not related to the immediate problem at hand, but potential future problems...


Move the insulation away from the pump motor for the indirect. That pump will overheat for sure...


It appears that the order of the pressure reducing and backflow preventer valves on the fill line is backwards. The back flow preventer is supposed to be closest to the domestic and the pressure valve closest to the boiler.
 

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Old 12-14-13, 01:23 PM
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is that amtrol air purger all i need? does it do the same thing as a spirovent?
It will work. It is basically a 'low-tech' version of a SpiroVent. They been used and working on systems for many decades.
 
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Old 12-14-13, 01:43 PM
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.............................................................................................
 
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Old 12-14-13, 02:02 PM
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Where is that condensate tubing going? UP? ABOVE the boiler? How is condensate going to go UP?
 
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Old 12-14-13, 03:00 PM
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ok, answering your questions in order:

1. yes it's worked fine before. when i bought the house with the ancient boiler, it worked fine. when i had the buderus installed, after the installer allegedly balanced the system, it worked fine. the ONLY issues i had with the boiler system for the 2 or 3 years after it was installed was that one or 2 rooms would be either too hot or too cold sometimes, but it would always cycle after a few hours/half a day. now the rads that occasionally got cold are apparently always cold, and the ones that were sometimes too warm, are always too warm.

2. main circ pump, is in the first picture i uploaded, looking at the boiler. it's mounted vertically, directly below and to the right of the boiler (it came as a part of the manifold). the other circ pump (horizontal), is running to the indirect heater, which you've already mentioned.

3. should all that smaller diameter piping be replaced by 1.5" then? if that's the case, would that mean i'd need any larger fittings? like that air purger? what size (pipe) filter should i be putting on there? either magnaflow/fernox/spirotrap. probably largest possible, if i'm to be changing pipe size out anyway? if not, just to match the 1" or 1.25" that's on there.

4. the goo out of the vent, yea i didn't realize it was coming from where it is either, until i saw the picture. makes me think it's a whole bunch of sludge in there...

5. need to change the order of the backflow/pressure reducing valve. got it. does that need to be done ASAP, or can that wait until the heating system is not in use, during late spring? i'm hoping to either travel back to ontario and deal with the rads/valves on the rads myself, or get someone to deal with it then.

6. should that air purger be replaced with a spirovent? if so, like i'd mentioned earlier, should i opt for the largest size possible for my setup (1.5"?)

7. that condensate line is actually joined together with a tee - condensate directly from the boiler, along with the flue gas condensate, which is also drained back. don't worry, nothing is getting pumped up and over there actually used to be an inline float pump, pumping away the condensate before i dug a sump pit in that room. i got rid of it, and the condensate line now has a lower section of tubing that i've cemented into the floor, leading to the sump pit as well.



i guess my biggest concern is:

a) it's not heating properly, their young daughter's room is the one having issues, and my tenants are freaking out (justifiably). it has been -25 to -30 outside with a boiler that's been running full tilt, but hasn't been successfully heating the whole house

b) if i go and install a bunch of these new parts (potentially new piping with a new air eliminator, new expansion tank, new dirt collector), will they all just be doomed in a short time because of what i'm guessing is a whole whack of sludge built up in the pipes/rads?

i'm ok with a band aid solution to limp through the winter, as long as it doesn't further damage any of the fittings, or the boiler/heat exchanger itself. if not, i'm thinking it needs a proper flush, and then all the new parts installed.

i also don't fully know what i'm talking about (here's where you can chime in again)...
 
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Old 12-14-13, 03:37 PM
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2. main circ pump, is in the first picture i uploaded, looking at the boiler. it's mounted vertically, directly below and to the right of the boiler (it came as a part of the manifold). the other circ pump (horizontal), is running to the indirect heater, which you've already mentioned.
So you mean that the pumps in the pictures are the only 2 pumps?

Look at my diagram... I took (and modified a bit) that drawing directly from the install manual for your boiler. There are THREE pumps. The two you mention, and a THIRD PUMP that moves the water through the radiators.

If you are telling me that there is not a third pump, then I honestly don't know how this could have ever worked from day one.

The pump you are calling the 'main circ pump' is NOT the main circ pump. That is the pump on the SECONDARY loop that moves the water in and out of the PRIMARY loop. That pump is only responsible for the flow through the boiler itself. It does not circulate the water through the radiators.
 
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Old 12-14-13, 03:39 PM
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now the rads that occasionally got cold are apparently always cold, and the ones that were sometimes too warm, are always too warm.
That's because the only circulation that you have in the system without the primary pump is by GRAVITY, aka THERMOSIPHON.
 
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Old 12-14-13, 03:40 PM
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well i guess that'd be another item to add to the list. i was second guessing myself after i replied when i saw 3 pumps on your diagram.

i was always impressed that that little pump was able to heat the whole house. could it be that because this was likely a gravity-fed system way back when, when it was converted to a circulated system, it didn't take much effort (until now) to circulate the pipes?

would i need a larger pump than the 2 grundfos pumps i have in there?
 
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Old 12-14-13, 03:40 PM
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3. should all that smaller diameter piping be replaced by 1.5" then?
At this point, now that I know you are missing a pump, it may be premature to say so...
 
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Old 12-14-13, 03:43 PM
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would i need a larger pump than the 2 grundfos pumps i have in there?
I think rather than the 15-58 that's there, you may want something with a little more ballz that that. The 15-58 is 'more or less' capable of doing the same thing that the Taco 007 can do but I would be more comfortable saying to use a 007 here...
 
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Old 12-14-13, 03:45 PM
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4. the goo out of the vent,
What bothers me more about that is the question: "What exactly IS that goo?"

How thick is it? Is it just 'black water'? or is it actually thick 'goo'?

If it's just black water, it would not concern me a bit.
 
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Old 12-14-13, 03:47 PM
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5. need to change the order of the backflow/pressure reducing valve. got it. does that need to be done ASAP, or can that wait until the heating system is not in use, during late spring?
Yes, it can wait. The worst thing that will happen is that the vent on the backflow preventer may start dripping. If it does, put a tube on it to a bucket.
 
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Old 12-14-13, 03:52 PM
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6. should that air purger be replaced with a spirovent?
You are going to have to add a pump... and that pump should be pumping away from that air purger / expansion tank, so you could change it if you felt the need. Honestly, I don't think there's any huge advantage... but others will tell you that the SV works oh so much better... prove it I say.
 
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Old 12-14-13, 03:55 PM
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the condensate line now has a lower section of tubing that i've cemented into the floor, leading to the sump pit as well.
You're aware that the condensate is ACIDIC, correct? Just look at the pipes it's been dripping on.

What moves the water out of the sump pit? Cast iron pump? Is the piping out of the sump pit metal? Any metals will experience accelerated corrosion from the acidic condensate.

The condensate will also EAT any concrete products.

Think about adding a NEUTRALIZER to the condensate line before discharging anywhere.
 
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Old 12-14-13, 03:57 PM
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a) it's not heating properly, their young daughter's room is the one having issues, and my tenants are freaking out (justifiably). it has been -25 to -30 outside with a boiler that's been running full tilt, but hasn't been successfully heating the whole house
Because there is no circulation other than thermosiphon in the radiators.
 
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Old 12-14-13, 04:01 PM
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b) if i go and install a bunch of these new parts (potentially new piping with a new air eliminator, new expansion tank, new dirt collector), will they all just be doomed in a short time because of what i'm guessing is a whole whack of sludge built up in the pipes/rads?
As mentioned previously, if it's only 'black water' there's no problem. If it's thick gooey sludge then you need to deal with that, but again... I don't think any of the guys on this board have ever seen thick gooey sludge circulating in a hot water system.

I want to believe it's just black water and that is NORMAL. It's MAGNETITE suspended in the water and it won't hurt anything.

If you have SEDIMENT circulating, you need to deal with that. That can clog up the heat exchanger in the boiler.

Your first order of business is to get a circulator pump installed on the system piping, pumping away from whatever air eliminator you choose (with attached expansion tank).
 
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Old 12-14-13, 04:03 PM
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i'm ok with a band aid solution to limp through the winter,
Get a pump installed ASAP.

Deal with the rest after.
 
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Old 12-14-13, 04:12 PM
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if i was to go for that taco pump, is that integral flow check feature needed? (they seem to be around the same price anyway).

haven't confirmed with my father yet, but from the picture, it does just look like water with magnetite in it (that was the original reason for me wanting to grab a magnetic/particle filter). here's hoping!

that condensate line goes to a sump pit that i dug, and just embedded a 5 gallon plastic pail in concrete. it is gravity fed to city drains via ABS pipe. there's always water in the pail (around 4"), and when it reaches that 4" mark (probably a gallon or more of water), it begins to drain. not sure if that's diluted enough for the condensate.


can all these fittings stay on 1" pipe, do you figure? wondering if i should also buy a box of 1" ball valves, since i know i need more isolation on there anyway (even before another circ pump).
 
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Old 12-14-13, 04:16 PM
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also, thanks again for all this info. i've had 3 or 4 boiler 'experts' down in that room over the past few years, and not one ever mentioned installing a separate circ pump for the rads.
 
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Old 12-14-13, 04:46 PM
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if i was to go for that taco pump, is that integral flow check feature needed?
It's not a bad idea... you know already that there is gravity flow in the system. Once you get the system pumping properly, the rooms that were too hot before may now ROAST because of the gravity flow... yeah, can't hurt.

embedded a 5 gallon plastic pail in concrete
I'm sure you left the top open, right? Throw a bag of garden center marble chips in there and you'll be fine. When the marble chips disappear (they will) throw in another bag. Simple neutralizer... and the reality is that the neutralizers made with PVC pipe are nothing more than what I'm suggesting now!

i know i need more isolation on there anyway (even before another circ pump)
No... nothing comes before the added pump.

When you install the pump, use ISOLATION FLANGES and that takes care of some isolating right off the bat.

PEX - Radiant Heat - Radiant Heating - Plumbing Supplies - PexSupply.com

They are kinda pricey, but they also have flanges with check valve built in... you wouldn't need the IFC pump then.

Stick with the 1" pipe for now and see how it goes. You may just get by with no problem once the system is circulating.
 
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Old 12-14-13, 04:47 PM
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i've had 3 or 4 boiler 'experts' down in that room over the past few years, and not one ever mentioned installing a separate circ pump for the rads.
Given what I've seen and heard over the years, I'm not at all surprised.

It's sad really.
 
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