Wiring Question

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kopeck

Minister of Fire
Mar 24, 2011
536
Maine
The main part of this is about my oil boiler but it is wood related as the end result is hooking up my Tarm to my current system.

I have a Taco JVC-406, a Riello F-3 40 burner installed on a BIASI boiler. The way it's currently wired is in what Riello calls the 120V setup. Pretty much the burner and the zone controller operate independent of each other as far a firing goes. The burner is kicked on by an aquastata that mounted on the boiler and the zone controller just manages the zone valves and kick on the circulator pump when there's a call for heat.

I'm not really sure how common this setup is, it seem like I read a lot more about folks using the 24V setup, and the main end switch (TT) to control the boiler.

I was talking to a friend who's family is in the heating business and while he went in another direction he's been around it all his life. He wasn't familiar with my configuration and thought it might not be the most efficient since even when there's no call for heat the boiler is always going to be kept hot. I suspect this setup is why I get random short fires during the winter (it kicks on when there's no call for heat for less the 30 second then kicks off).

Anyway, I'm not sure if there's a right or a wrong way but what's the thoughts on how my system is setup? If anything, it seems like a very simple way to wire up a boiler.

Ultimately I'm going to need to be able to turn my oil boiler and it's circulator off when my my storage tank is up to temp. The folks that sold me my Tarm sent along a Johnson Controls A419 to do the "switching" but it's a 24V version so that's not going to work for me at the moment. I'm also going to have to use a relay since I'm really turning off two systems (the burner and the pump), just looking around it sounds like a Functional Devices RIB2401D would do the trick.

Sorry for this being so long,

K
 
Hello

Well, the first item to check.

The oil boiler must be a Low Temperature (Cold Start) boiler in order to shut it down or turn it on and off.
My cast iron Buderus Logano has a special iron formula GL-180M with silicone to give it more elasticity for this operation!

Boiler vessels that are not Low Temperature will prematurely fail from the large on-off temperature changes!
 

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Well, I just did some digging and it looks like the B-10 boiler is a cold start. So I guess I'm wondering why my cold start boiler seems to be kept warm all the time? Maybe I'm missing something here but as far as I can tell the thing is kept warm all the time by the Honeywell L4006 on the back.

I'm going to have to do some more investigating. I've read everything known to man about my Tarm, I feel I have a pretty darn good feel for what's going on there, I'm just getting to know my oil rig. I figured it was installed correctly since a "Pro" did it, but I'm finding more and more things that make me wonder about the job.

K
 
Does your oil boiler currently provide your hot water as well? That could explain why it would be kept hot...
 
So I went down and grabbed the manual that came with the boiler and it had a complete wiring diagram for my setup, burner, boiler, and zone controller. It wasn't in the PDF that I grabbed earlier and now it's very clear how the whole thing works.

It is a cold start boiler and it is wired that way. I was wrong, it doesn't stay warm. During they day it looks like it stays warm but that's due to the indirect DHW calls for heat, at 11:30 last night it dipped down to 130F, the aquastat is set to kick on at 150F.

Interestingly enough my plumber did not wire it per the diagram. Everything (burner & circ. pump) is run off the "Extra End Switch", oddly enough he left the "Main End Switch" empty. I don't think it matters which end switch you use, they seem to serve the same purpose.

What he did wasn't by the book but I understand how and why it works now. I don't think it's wrong, just different.

The good news is if I just keep things they way they are all I have to do is put the A419 on the output of the end switch and it will control both the boiler and the pump. Pretty simple...

K
 
Hello

That's good, glad your all set.

If you want to make the DHW indirect tank not call for heat as much then you can do 2 more things that I did.

1. Add a heat loop on the DHW output of the tank in the plumbing.
12" down 12" across and 12" backup. Now heat will not convect out the top of the tank all night thru the plumbing to the faucets!!

2. A DHW expansion tank on the cold line input to the DHW indirect tank.
When the water is heated and expands in the tank, instead of loosing heated water out of the top, you just lose only a very little cold water out the bottom!

See pic below of Heat Loop and DHW Expansion Tank!
 

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