Best Of
Re: Red tubing yay or nay
It's PEX, specifically PEX-B.
The Radiant Floor Company sold ½" and 7/8" tubing; with each size, they made one with and one without an oxygen barrier. From the writing on the tubing, it looks as though what you have there is without the oxygen barrier, so you might get some corrosion of ferrous components.
And it also looks like you have a high temperature system with bare tubing in the joist bays. High temperatures promote more oxygen diffusion, so a HX may be indicated to save the system although you will have to run a higher boiler temperature because of HX inefficiencies.
More about the tubing here.
Re: Is this a steam trap?
With all the unions on the header you could cut the risers from the boiler and turn the header 180 degrees with the tees pointing up.
Come out of the boiler with a nipple then 2 45s and 2 90s and make it a half A—-d drop header .
Re: 90%+ Boiler vs 80% boiler
i think the total cost of ownership might be a little better with the ci boiler on a high temp system due to the longer life but i have nothing against putting a mod con on it either. I was more arguing that a mod con had very clear benefits in simplifying a lot of the complication on a gravity or radiant system.
mattmia2
Re: Taco needs to create an animation of how the 570 series zone valve works.
This is where the confusion starts: "Terminal 2 receives 24V from R on the transformer."
Don't think of it that way. That's how transformers get the factory-installed smoke to leave them.
Think of Terminal 2 as a common, or C terminal. When you look at it that way, it always makes sense. The problem is that not everyone thinks that way, and that's where the trouble begins.
When you come across a Taco 570 Series three-wire motor, where the transformer's 24V R is connected to #2 or common (C), things can get confusing. Eventually, when diagnosing a problem involving a transformer with R connected to the #2 or C terminal on a zone valve motor, you can end up connecting an R and a C from a transformer together.
We all know what happens when you connect R and C together on a transformer and then apply 120V to the primary winding. the factory installed smoke is released.
So think of the taco 570 series motor like this. R from the transformer goes to R on the thermostat. That makes sense all the time weather toy are wiring a heater or air conditioner or heat pump. R is always connected to R and if you use a Red insulated wire that makes it even easier to remember.
Now that you have connected one of the transformer wires to R on the thermostat, you need to connect W (the heat terminal on the thermostat) to something. That should be terminal #1 on the Taco 570 motor. This means that whenever there is a call for heat, the thermostat will send 24 VAC to the Taco motor.
However, that does not make a complete circuit for the Taco motor. You need a return path for the circuit to be complete. This is where terminal #2 becomes a Common (C) terminal. All you need to do is connect terminal #2 on the motor to C on the transformer. This completes the circuit.
That is really all you need to know about the Taco 570 series valve motor. There is more to learn, but if you want the basics to get it right every time, remember this:
Transformer R → Thermostat R (use the Red insulated wire)
Thermostat W → Taco 570 Motor Terminal #1 (use the White insulated wire)
Taco 570 Motor Terminal #2 → Transformer C (I like Blue for this, but use what ever color you have left in the bundle if spaghetti because electric is colorblind)
Once you have this circuit in place, you can then use terminal #2 (Common) and terminal #3 on the Taco 570 motor as an end switch, independent of the thermostat circuit.
Re: Is this a steam trap?
it is a vapor system, it doesn't have traps. that is i think a water seal, maybe it is a broomell system.
don't let them touch it unless they understand what a vapor system is.
the boiler through correct sizing and a vaprostat keeps the pressure low, under about 8 oz/in^2 and that vapor valve on the radiator meters the amount of steam that is let in to the radiator to less than what the radiator can condense so it is all condensed to water before it gets to the outlet of the radiator.
keeping the pressure very low, a few piping things and possibly some specialties at the boiler are critical to making that system function properly.
mattmia2
Re: 90%+ Boiler vs 80% boiler
Not to hijack this thread, but I wish this knowledge was more widely known, that a modcon is (almost always?) the correct choice for a gravity conversion.
When I recently had my boiler replaced (before I had discovered this forum and Dan's books), I specifically selected my contractor because he walked through my home, took measurements, looked at all my radiators, and did a manual J, while others didn't. He talked me out of a modcon, on the theory that I'd only be in condensing temperatures during shoulder season, and that it wouldn't be worth the extra cost. However, as I document in other threads here, my home is massively over-radiated, and is, as @mattmia2 says, "obviously" a good candidate for a modcon. But instead I got a cast iron boiler, with (initially) no low return temperature protection.
As a homeowner you are usually advised to follow the wisdom of experts, which I thought I was doing…. But then I found HH ;)
Re: 90%+ Boiler vs 80% boiler
The boiler buddy may give you longer cycles — but unless you can get the operating return temperature below 140 F or so — and lower is better — you'll do no better with a high efficiency boiler than with a regular one.
And doing that depends on whether you have enough radiation (you mention fin tube — so that would be total length of fin tube) to heat the structure adequately at low temperatures. Heating systems are SYSTEMS — not random collections of components — and how well they work depends very much on the whole system being considered as a whole, not just a boiler here and some radiation there! You may simply not have enough radiation installed to make a "high efficiency" boiler work at high efficiency.
Re: 90%+ Boiler vs 80% boiler
More likely than not the high efficiency boiler isn't running at high efficiency — as noted above, it has to have relatively cool return temperatures to do that, and it probably isn't set up and controlled to do that Iif it even can — depends on the radiation which it is powering).
Re: Taco needs to create an animation of how the 570 series zone valve works.
They are a bit confusing at first — I certainly was anyway! But the secret is that the three terminals are really two completely different circuits. One (1 and 2) powers the zone valve to open when it gets power — from somewhere. The other 2 and 3 — is a simple limit switch which closes when the valve is open. Apply power to 1 and 2, and the valve motor is energized and the valve opens. When it is opened, the limit switch closes between 2 and 3 and you can use that closure for whatever.
Now there is a ringer in the deck: terminal 2 is common to two circuits. Whatever is sending the signal to open the valve is one circuit. Whatever the valve is telling to operate is the other.
Those circuits must be independent. In theory, under certain miswiring conditions, it is possible to set them up so that they can short out, but if both the independent 24 VAC circuits are intact and NOT GROUNDED this won't happen.