Help on Dual Boiler setup Coal-Propane

[layoric]

Ahh, but the coal boiler pump P1 is pumping up in the as-currently-plumbed diagram!

Like I said, that arrow was my mistake.

 

[layoric]

@layoric: How about a close up well lit picture of the LP boiler pump so we can see for ourselves what direction it is pumping.

It is pumping DOWN. I did not notice the arrow is all as it is old and painted black.

 

[layoric]

Also, although with the figure-eight configuration the LP boiler will take over automatically if the coal boiler goes offline, when it does you there will be parallel flow through the coal boiler until the coal boiler is manually isolated (or automatically isolated with a powered valve).

What if, along with moving the LP circ as you suggested, he also turned it around so it was pumping up rather than down? (The way he thought it was pumping first). And either used a checked circ on the coal loop or put in a check valve there? Although the hot coal water would then need to go through the LP boiler before it got to the zones. Also sounds like there is still a question on whether the zone valves are pointing the right way, since there was confusion about which way the water was going.

On the DHW thing - I assume that setup is a tankless coil in the coal boiler, in series with an electric hot water heater? Don't think that has been clarified for sure. If so, I think there are a couple of ways to improve that situation. First, don't mix down between the coil & electric heater as shown. Rather, put a mixer on the DHW-out of the electric water heater, between it and the taps. If that was still not satisfactory, you would for certain have all the hot water you would need if you added a small recirc pump (I have a B&G Ecorcirc E^3) that would circulate the water between coil & heater when there was no hot water being used. I control mine with a Johnson A419 in a FPHX setup. Also don't know how big the electric heater is either - but the bigger the better for that, if a lot of hot water is being used.

The water tank is on a bypass, and turned off. It's a 50 gal. I don't think I want the guy to touch it, he wanted to plumb into the emergency blow off valve as intake for the water heater. Doesn't sound safe to me. Don't want him to frig up more stuff.

 

[ewdudley]

Like I said, that arrow was my mistake.

Like I said, the coal boiler pump, P1, is pumping up through the zone valves, not the LP boiler pump, P2, which is shown pumping down. (At least it is according to the 'This is the setup as it is NOW' diagram.)

 

[layoric]

That would take care of the DHW reserve problem nicely, which removes the main advantage of going with the figure-eight.

So now I would say don't do a series, don't do a figure-eight, and go ahead with figure 3 above with the addition of appropriate check valves or integrated flow-checks. The water-hammer and overheating problems can be dealt with separately.

Where would the check valves go? I think one would go to the right of the zone valves dotted lines, just before the supply T connection, but the other one goes where, so as to get flow to the zone valves?

 

[layoric]

Like I said, the coal boiler pump, P1, is pumping up through the zone valves, not the LP boiler pump, P2, which is shown pumping down. (At least it is according to the 'This is the setup as it is NOW' diagram.)

Yeah, it looks like as it is now, the coal pump goes to zone valves and just sits there, waiting for a valve to open. I guess this is why it's overheating.

 

[ewdudley]

Where would the check valves go? I think one would go to the right of the zone valves dotted lines, just before the supply T connection, but the other one goes where, so as to get flow to the zone valves?

In the third 'This should be the setup in PARALLEL' drawing (two check valves, one for each boiler):

For the P1 coal boiler circuit the check valve could go anywhere in the supply line after the supply bypass tee and before the next tee, or anywhere on the return side before the return bypass tee and after the tee on the return side of the LP boiler, or it could be a IFC, integrated flow check inside the P1 pump assembly itself if you go with an IFC type pump.

For the P2 LP boiler circuit the check valve could go anywhere in the same section that holds P2 itself (after the tee and before the boiler), or anywhere on the supply line leaving the LP boiler and before the first tee, or it could be a IFC, integrated flow check inside the P2 pump assembly itself if you go with an IFC type pump.

 

[layoric]

OK everyone, I think a parallel setup is best. Also, since it's almost there anyhow... So I can have the power for the zone valves / tstats moved to a separate circuit, that way which ever boiler is turned on, it's not dependent on the other for power. Now for the check valves, relating to the parallel diagram, where would they go exactly? I also believe that if the pumps are wired to turn off/on, then they will turn off with the zone valves - will that eliminate the water hammer issue as well?

 

[layoric]

In the third 'This should be the setup in PARALLEL' drawing (two check valves, one for each boiler):

For the P1 coal boiler circuit the check valve could go anywhere in the supply line after the supply bypass tee and before the next tee, or anywhere on the return side before the return bypass tee and after the tee on the return side of the LP boiler, or it could be a IFC, integrated flow check inside the P1 pump assembly itself if you go with an IFC type pump.

For the P2 LP boiler circuit the check valve could go anywhere in the same section that holds P2 itself (after the tee and before the boiler), or anywhere on the supply line leaving the LP boiler and before the first tee, or it could be a IFC, integrated flow check inside the P2 pump assembly itself if you go with an IFC type pump.

Is this the correct location/orientation for the check valves?
I believe I could then have the opposing boiler completely off (with valves/tstats powered separately), is that correct?

Thanks again ===

 

[leon]

Water hammer is nasty because it can and will blow plumbing apart.

I would install another bladder sized to your pump ahead of the zone
valves based on your diagrams.

 

[layoric]

For my last parallel diagram, will I need a 4006a installed?

 

[ewdudley]

Is this the correct location/orientation for the check valves?
I believe I could then have the opposing boiler completely off (with valves/tstats powered separately), is that correct?

Thanks again ===View attachment 142387

The check valve on the PI return circuit is pointing the opposite direction of what you want.

The other check valve needs to go anywhere in the same section that holds P2 itself (after the tee and before the boiler on the return side of the LP boiler), or anywhere on the supply line leaving the LP boiler and before the first tee, or it could be a IFC, integrated flow check inside the P2 pump assembly itself if you go with an IFC type pump

Get a couple of these, one for each boiler. Will save a lot of electricity and will save the expense of sweating in separate check valves. Also should help a lot with water hammer since they will adjust flow automatically according to how many zones are calling. In the meantime just isolate the boiler you're not using with the valves you already have.

http://www.pexuniverse.com/grundfos-alpha-15-55f-lc-circulator-pump-w-ifc-1-6hp-115v

 

[ewdudley]

For my last parallel diagram, will I need a 4006a installed?

Edit: (thought you were talking about the 4006B)

Yes, the 4006a activates your 'dump zone' in case of overheat. It is simply wired in parallel with the thermostat of the zone best suited as someplace to dump some excess heat in case the KAA-2 overshoots. See page 11 of the manual:

(broken link removed to http://www.keystoker.com/manuals/2012/Hot-Water-Boiler.pdf)

 

[layoric]

Yes, the 4006a activates your 'dump zone' in case of overheat. It is simply wired in parallel with the thermostat of the zone best suited as someplace to dump some excess heat in case the KAA-2 overshoots. See page 11 of the manual:

(broken link removed to http://www.keystoker.com/manuals/2012/Hot-Water-Boiler.pdf)

Well, he's here now. Guess what? With the diagrams illustrating the zone valve directions, I was correct, however, he noticed another of his mistakes and said they're supposed to be pointing down, just as many of you stated. He's now flipping the zone valves... so, he's tied into the supply side at the end of the zone valve, and installed the 4006a off that new connection. The valves will be powered separately (not tied to boiler power directly), and also valves wired together to allow some crap I can't remember cause I'm spinning at this point.

Now they're going in series, as it was explained by him to allow only the lp system to run when coal is out, off, or low temp. Also allows more recovery of domestic hw if coal can't keep up, which shouldn't happen as easily now, since there's now the loop between boilers.

Hopefully this is all correct once completed. I have a frigging headache [emoji44]

 

[leon]

Well, he's here now.

Guess what? With the diagrams illustrating the zone valve directions, I was correct, however,
he noticed another of his mistakes and said they're supposed to be pointing down,
just as many of you stated. He's now flipping the zone valves... so, he's tied into the supply side
at the end of the zone valve, and installed the 4006a off that new connection.

The valves will be powered separately (not tied to boiler power directly), and also valves wired
together to allow some crap I can't remember cause I'm spinning at this point.

Now they're going in series, as it was explained by him to allow only the lp system to run when
coal is out, off, or low temp.
Also allows more recovery of domestic hw if coal can't keep up, which shouldn't happen as easily
now since there's now the loop between boilers.

Hopefully this is all correct once completed. I have a frigging headache [emoji44]

-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

Yay!! you should have plenty of domestic hot water now.

If you have to you can open the air shutters on the blowers now if you need more combustion
air to make more heat.

 

[layoric]

Here's what seems to be a working setup now, no hammering either!

 

[layoric]

OK, NO HEAT!
The guy tested the ZV's manually, but never the Tstats or radiators to ensure all was working. No water flow... WTH? Looks like the last ZV / zone got heat, but others before it did not. I don't get it...

Left messages on his 2 #'s. Pissed...

 

[maple1]

So - do you get heat when you open them manually?

Think this is now between you & him - hard to fix some things over the internets.

 

[ewdudley]

So did you sign off on that last piping schematic before the guy started work? I can't make any sense out of it.

Maybe you can post a photocopy of the electrical schematic that was drawn up before the job was started. (As if.)

Looks like you're on your own as far as I'm concerned.

 

[layoric]

No, didn't sign off an jack. I just wrote it out for what he did. I'm not on my own, unless you just mean you're not offering suggestions - not sure what you mean.

I figured out the ZV/room return lines, as stated several times, that was just confusing, but this is exactly what it is - including the returns. It looks to me as though there's no way for heated water to flow to the rooms...

 

[layoric]

So - do you get heat when you open them manually?

Think this is now between you & him - hard to fix some things over the internets.

Nope.

 

[leon]

It looks exactly as if the water flow is stalled completely
with the circuits you have drawn.

I still think you need a common return header pipe from
all four zones.

 

[leon]

Hello Layoric,

I cannot blame you for being angry at all

The lack of a comom return header pipe routing the
cooler return water from the four zones is still the issue as the
heated water flows per the diagram are stalled and can go nowhere.
-----------------------------------------------------


Taking my basic wood and coal system into account which has been in use for 32 years-
old house/poor insulation with one loop.

I have a single air scoop with a B+G air vent coming from my external domestic coil from my wood and coal boiler that splits into a T to feed both zones with one thermostat. Both zones return with a common header pipe back to the oil boiler.

Both of the three speed B+G pumps pull hot water from the base of the oil boiler with one circulating the hot water through the homes baseboard.




The second pump is pumping hot water between both boilers to balance the water temperature between the boilers when burning wood and coal leaving the oil boiler to run only when the wood and coal boiler cannot supply the heat needed if the fire dies out.

Both of the three speed pumps in my system are on the lowest speed setting.

I wish I could be of more help to you but your system was made complicated
when it did not have to be because of the zone valves "in my opinion" as heating at 62-65 degrees as I do the system can heat the home and lose the least amount heat through my poorly insulated home.

 

[maple1]

Thought we were almost there with the diagram in post 59 - except for the checkvalves mentioned in post 62.

And the dashed red arrows pointing up rather than down.

Don't know how you ended up with post 70 piping - was that his call?

Those isolation valves are making some confusion also - system should function the right way (either boiler can heat) without manual intervention & opening & closing of valves. And with them in the diagram like that, it is not known if they are open or closed or when.

About all I have left to say I think is good luck.

 

[layoric]

Valves are open unless oriented to cross a line, so only the one is closed.
Spoke to a lawyer, he said installer should be given opportunity to fix it. I said, HE WAS, several times - lawyer didn't listen to me very well... However, got another hvac guy to come out, set for a time after installer coming BACK tomorrow.

Manufacturer said to do the following:


That gives you supply-return, supply-return. DONE. Keystoker said that wouldn't create a hammer either.
The installer was here for TWO hours, trying to figure out his own work... Then he said he didn't have the parts, would get them, and come back after another job tomorrow morning. I later realized he could have just disconnected his recent screwup connections and ran them to the correct points, without any new parts, but whatever - At this point I know what to do, but if I do it, and it still don't work, I don't want to be screwed on that. This will be the last time this guy comes out to figure this out, then I'm either going to do it on my own, or pay again, to someone else. The only thing I'd have to figure out would be wiring if I did it myself. I made a joke that perhaps he should just connect everything together with zone valves, and keep turning them until he got it to work! He laughed.... Then suggested, well, just think on what it should be from scratch if you can't figure it out, then eliminate from there what isn't needed, connect what is. Also suggested to consult someone else, gave him the 'current, as is now' diagram if he found a friend to do that, before he comes out (for the last time).

I have another guy scheduled to come out to look at it tomorrow evening as well. Spoke to the now third hvac guy over the phone, he was saying we don't use zone valves any longer, no one should. We install pumps on every zone, otherwise you can't drain the lines all the way. ---- Pumps may be better, but the house only had one for years, and it worked just fine until it was fubar'd.