heating pipes

About a year ago I purchased and moved into an old two story 1989 Victorian home in Kansas and now I am in process of restoring this grand old home. Over the winter I noticed some of the heating radiators were working well but others did not seem to get hot. The gas hot water boiler in the full basement is about 20 years, works well old and is not a steam boiler.

I was not able to figure out the problem with the non working radiators. The valves were fine and were blead out ok. We do want to keep this heating system.

I asked an old retired heating guy to take a look at the system. He told me it is a one pipe system. Big old 3" pipes go around in a big loop and the radiator feeds come off the top of the pipe and the return goes to the middle of the same big pipe. He suspects the system was originally a steam system but was converted to a hot water boiler. Water of course will take the path of least resistance [the three inch pipe] and only passes through the radiators as it feel like it.

Does this hypothesis sound correct and if so how do I persuade the water to pass through ALL the radiators

Post some pictures also the radiators that are not working are they at random spread out through the house or is it upstairs ones aren't working downstairs ones aren't working?

voletl said:

Post some pictures also the radiators that are not working are they at random spread out through the house or is it upstairs ones aren't working downstairs ones aren't working?

Click to expand...

Two radiators upstairs out of 6 are not working, and three radiators downstairs out of seven are not working.
Attached is a piping layout, the supply and return for a radiator and three typical radiators.

Are there bleeders on the opposite side of the radiator valve. If you open the bleeder up you should get water. If not then the
radiator is probably plugged. Are you positive the valves are letting water into the radiator. It sounds like you have a mono-
flow boiler system.

TomFOhio said:

Are there bleeders on the opposite side of the radiator valve. If you open the bleeder up you should get water. If not then the
radiator is probably plugged. Are you positive the valves are letting water into the radiator. It sounds like you have a mono-
flow boiler system.

Click to expand...

Yes I have checked all the bleed valves and no air is in the radiators, just water.

Rod

TomFOhio asked, "Are there bleeders on the opposite side of the radiator valve."
The pictures show that the bleeders are on the SAME side of the valves.
Is that not a good enough test for flow through the radiator?

It would appear that the one loop from and back to the boiler is circulated by a pump, while each of the radiators are individually piped off of risers from that loop, using the gravity system.(or possibly the monoflo/diverter tees.)

I would identify those radiators, that are not working, on the diagram.
BTW...your text refers to 13 radiators while your diagram shows 12. One seems to be missing from down stairs.

Referencing the picture of "the supply and return for a radiator" I question the theory behind the hot line coming off the top of the 3" being a much smaller size than the return coming back into the side of the 3". Does anyone have any idea or speculation as to what if anything that would do.
Unless of course they're different sizes for upstairs and down stairs. ???

Diehard said:

TomFOhio asked, "Are there bleeders on the opposite side of the radiator valve."
The pictures show that the bleeders are on the SAME side of the valves.
Is that not a good enough test for flow through the radiator?

If a radiator is full of water, water will come out of the bleed valve even if either the supply or return line is not flowing.

It would appear that the one loop from and back to the boiler is circulated by a pump, while each of the radiators are individually piped off of risers from that loop, using the gravity system.(or possibly the monoflo/diverter tees.)

I would identify those radiators, that are not working, on the diagram.
BTW...your text refers to 13 radiators while your diagram shows 12. One seems to be missing from down stairs.

I think there are actually only twelve radiators. My bad.

Referencing the picture of "the supply and return for a radiator" I question the theory behind the hot line coming off the top of the 3" being a much smaller size than the return coming back into the side of the 3". Does anyone have any idea or speculation as to what if anything that would do.
Unless of course they're different sizes for upstairs and down stairs. ???

Click to expand...

The supply and return shown in the picture are not going to the same radiator. It was just a convenient angle to shoot.

Rod Lloyd said:

If a radiator is full of water, water will come out of the bleed valve even if either the supply or return line is not flowing. Okay, so you're saying it is not a test to determine if radiator was plugged, which I believe was why the question was asked.

The supply and return shown in the picture are not going to the same radiator. It was just a convenient angle to shoot. Okay...So were the supplies and returns for the same radiators the same size?

Click to expand...

Are you able to identify which radiators, in your diagram, are not working?

You had mentioned that the valves were fine. Did you happen to compare the number of turns it took to open a working radiator vs the number of turns it takes to fully open one of the radiators that are not working? Just trying to verify that the actual valve plugs were completely retracted when the handles were turned fully CCW?
I assume the valve handles do not just continue to rotate when opening.

I had a licensed heating guy come and study my system. He seemed very knowledgeable but did not know why it was not working. He gave me an estimate to add a pump to each non working radiator, each with its own thermostat to force the water through it, indicating it would give the benefit of making that room independently controllable using its thermostat.

The plan seems plausible but does not diagnose why it is not working currently.

I would like feedback if I should go with this plan.

Hello Rod
you have a 1 pipe system and it is piped incorrectly.

you have this...

What you have to have for a HYDRONIC one pipe system, is this.....

your plumber is correct, adding a pump at each radiator will give you control of the radiator.
the question is. cost
their are 3 ways you can go here
1] add the pumps as suggested
2] remove the pipe between the tees like i show in my drawing, pipe the water through each radiator
3] add a second line, a return line running parallel with the 3'' supply
add a zone valve at each zone controlled by a t stat
n my opinion. your system is due for a new boiler due to the age, the piping looks to be very old and is most likely half full of sludge, replace boiler, tear out the old piping and re-pipe with a 2 pipe system
this is the more expensive option but an option that will last another 25/30 years

2nd solution
add the pumps, it is the cheapest way out

If one can assume that the system was once working as it's been depicted by the OP(as an old gravity system for the upper two levels, with a circulating lower level loop), then it's a matter of what has changed.

If the radiators that do not heat up are partially clogged, not allowing the gravity flow to work as designed, changing it to a series arrangement may be a mistake, as it would affect all the radiators downstream of those partially restricted units. Not to mention that different radiators apparently have different size pipes, which would not lend itself to a series arrangement.

The OP has indicated a desire to keep this heating system. In order to consider that approach, at a minimum I would think that those radiators that are not working should be tested for their flow capabilities.
At a minimum, in an effort to avoid draining and taking portions of the system apart, we should first try to solve the puzzle of the lack of flow through specific radiators.

One thought I had was disconnecting a non-functioning, upper level(to minimize draining entire system) radiator to further inspect its flow capabilities and possibly even snake the riser pipes.

Of course, ideally would be to disconnect the feeds at the header, in what I assume is the basement level, to test the flow capabilities through a non-working radiator along with its feed and return pipes.

Any of this inspection work is likely more than the OP would want to take on himself, in which case the addition of circulating pumps for each of those 5 non-working radiators may be the easiest way to get heat from those radiators. Of course depending on how much and what is causing the restriction for those radiators may or may not pose a problem for the pumps.

The End

I have no idea what I am talking about, but is there any type of a de-scaler you can add to circulate through there, then drain and refill?

What about running higher pressure water backwards through the system, to knock loose any looser sludge, then drain and refill?

Can the non-working radiators be removed, then cleaned internally with de-scaler or some kind of pressure wash or forced flush?

I know, they have been on there for over a century, so getting things apart would likely be tough or cause breakage.

So feel free to ignore, but no need to ridicule the eager non-pro.

I did have a client with a house built in the 1860’s.

She said her parents had some weak radiators improved by some type of high speed vibration device that clamped on to the boiler, and the vibrations broke loose some of the crud.

Maybe that was just a scam, I was not a witness to it, just hearsay.

CORRECTION! I meant to say the vibration device clamped onto the RADIATORS, not the boiler.

Rod Lloyd said:

I had a licensed heating guy come and study my system. He seemed very knowledgeable but did not know why it was not working. He gave me an estimate to add a pump to each non working radiator, each with its own thermostat to force the water through it, indicating it would give the benefit of making that room independently controllable using its thermostat.

The plan seems plausible but does not diagnose why it is not working currently.

I would like feedback if I should go with this plan.

Click to expand...

My gut instinct tells me your original system was steam,and the boiler was switched out with a hot water boiler
and the piping was never changed.
the giveaway is the condensate return line on the first floor and the size of the piping.
3'' is way way over kill for a 2 story residential hydronic system
but is the perfect size for a steam system

I found this radiator sludge vibrating tool, the idea is similar to what my client described.

Only she remembers the tool as clamping on, not being pressed against the radiator.

Anyway, goofy or not, here is a link.

https://www.kamco.co.uk/data-sheets/power-flushing-accessories/RadHammer data sheet_17k.pdf

Rod, BTW I had assumed you meant 1889, not “1989” Victorian home!

you are correct, 1889. I am concerned about the sludge in the system. I have flushed the water out a couple of times and it come out clear but I know there is black sludge in the system. The tool mentioned says only use if copper pipe. My system is all black iron.

turn your heat on, after it has reached full heat
feel the bottom of the radiator...is their a temp difference between the bottom and top?;
if yes.
it is sludged

below is for use on black iron pipe

There is also a machine like a pressure washer, that connects to the radiator system and power-flushes the sludge.
And it catches some of the crud with big magnets.

I believe you have to take out one radiator to attach the hoses for the flushing machine.
But maybe it could also be attached at the boiler.

frodo said:

My gut instinct tells me your original system was steam,and the boiler was switched out with a hot water boiler
and the piping was never changed.
the giveaway is the condensate return line on the first floor and the size of the piping.
3'' is way way over kill for a 2 story residential hydronic system
but is the perfect size for a steam system

Click to expand...

Yes... it was mentioned in the original post that it was suspected that the system was originally a steam system but was converted to a hot water boiler.