Two Boiler Wiring

cutter

I have two boilers a wood fired boiler and oil fired boiler. I want to run them one at a time, not have one come on when the other no longer has power to it. I have drawn a wiring diagram of how I think it will work. I am not a HVAC tech, this is for my own personal benefit.



There are only two controls other than the thermostats and Honeywell V8043E zone valves and transformer. The control on the wood boiler is a Honeywell L6006A 1145 aquastat. Power comes in to R when there is no temperature R and B closes when temperature rises to a pre-set temperature R and W closes. On the oil Boiler there is a R8182E control that runs the boiler. What I was wanting to know is will this system work as drawn? The on/off switch from the B terminal on the aquastat will be off and the switch between the R8182E oil boiler control and gun will be off.



The wood boiler will get hot and power up the oil controls, The thermostats will tell the zone valves to open and the pump to come on and the gun to fire. The switch above the gun is off so it cannot fire. Will the pump still run with the burner tripped out because no flame was detected? Is there a better way to do this?



To run oil only close the valves close to the wood boiler and open the valve on the return from zones line, turn on the two switches that were turned off for wood firing and press the reset button.



Would there be any bad things happen running a system this way?

Zman

Questions

Is this thing already piped?

Is it an outdoor boiler?

Do you want the change over automatic or manual?

The easy way to do this is with double pole double throw relays and an aquastat.

Carl

cutter

Boirer picture

It is piped but not the way it is drawn. I need to re-pipe it. because it does not work like it should. Is there a better way?



The two boilers sit side by side in the basement.



Not sure what you mean by

Do you want the change over automatic or manual. I am not electrical and what I drew was the simplest way I could come up with. If there is a better way I am all ears



The easy way to do this is with double pole double throw relays and an aquastat. I would need a simple wire diagram or drawing to be able to do the double pole double throw relays.



Here is a picture of what the system looks like now. I need to re-plumb and re-wire it. Currently there is a wood and a oil thermostat for each zone. I was wanting one thermostat for for each zone. One picture is from years ago and the other is after I had the sheet metal painted.

Zman

Piping

Check out drawing 6-14 on page 29. I think I would do it like that if I did not need a buffer tank.  As the manual points out, buffer tanks are a good idea with wood boilers.

How are you dumping the extra heat?



As far as the wiring goes, I think that the whole thing would run simply and totally automatically if you just use the circulator output on the wood boiler control to set off a chain of events. Any time the wood boiler is hot, the circ will turn on. If the wood boiler runs out of wood, the circ will turn off. If you intercept the power to the circ with a relay, you can power on the oil boiler  anytime the wood boiler is cold and their is a call for heat.



I would clean up the zone valve t-stat wiring with something like a Taco ZVC406-4.



I can draw it up for you if you would like.



Carl

cutter

piping information

Check out drawing 6-14 on page 29. I think I would do it like that if I did not need a buffer tank. As the manual points out, buffer tanks are a good idea with wood boilers.

How are you dumping the extra heat?



I am new to this site and do not know how to get to page 29 drawings 6-24, could you give me a direct link? Or tell me how to get there.



I would like to have a buffer tank but do not have room in this boiler room.



To dump the extra heat when the zone valves were working, I have another Honeywell L6006A 1145 aquastat that opens a zone valve and turns on the pump to the largest zone in the house.



As far as the wiring goes, I think that the whole thing would run simply and totally automatically if you just use the circulator output on the wood boiler control to set off a chain of events. Any time the wood boiler is hot, the circ will turn on. If the wood boiler runs out of wood, the circ will turn off. If you intercept the power to the circ with a relay, you can power on the oil boiler anytime the wood boiler is cold and their is a call for heat.



What I would like to do is run one boiler or another. When I first put this system in (which was not done correctly) the house would lose a few degrees overnight. The next morning build a fire and get the house back up to temperature. With the zone valves shot the circulating pump runs when the boiler is above 140 degrees. Very seldom is there hot coals in the morning. When the zone valves worked I had hot coals in the morning a lot. It might be nice to wire in the option you mentioned and be able to use it or not use it by turning a switch off or on.



I would clean up the zone valve t-stat wiring with something like a Taco ZVC406-4.



I can draw it up for you if you would like.



I am not sure I know what you mean by clean up the thermostat wiring. I have heard a lot of praise for Taco but I am totally unfamiliar with Taco.



If you could link me to a drawing or draw it up that would be nice.

Zman

Link

Here is the link for Idronics  www.caleffi.us/en_US/caleffi/Details/Magazines/.../idronics_10_us.pdf‎



The Taco wiring is here www.taco-hvac.com/uploads/FileLibrary/100-92.pdf

cutter

boiler layout

I did not see the link below your last post so that is the one I looked at and saw what you were talking about. I had seen that bypass between supply and return lines before but did not think they were necessary. I think I know now why they would be an asset to a system. The oil boiler will not be there forever and the way the piping lay out is on page 29 would make it simple to swap the oil boiler for a gas boiler.



I like the layout but it would need to be explained to me there are fittings that I do not know what they are. On the bypass of the wood boiler there is a Thermoblock valve and on the auxiliary boiler there is a Thermostatic anti- condensation valve. I had thought the valve prevents a shock to the boiler by mixing hot water to the cold return. On the wood boiler it would prevent the wood boiler from cooling off and shutting down the system until the boiler temperature was reached again. Good idea!! Does the Hydraulic separator remove air from lines???



The taco link shows what is out there, but I have not a clue as to what would pertain to my system.



The last link to Idonics I did not have permission to see but I found your first link. Just did not see it at first. Thanks

Zman

Anti condensate

You need to protect conventional boilers from sustained return water temps lower than 140 degrees.Low return temps will cause the flue gas to condense in the boiler and/or flue resulting in damage.It is not necessary in every application it really depends on the type of emitter you have.

The drawing on page 32 in the taco file is similar to what you would need.



Carl

cutter

trade name

What would be the trade name for the thermobloc valve at the return port of the wood boiler? I could not find anything when I asked for a thermoblock valve.



When I looked for a anti-condensation valve I came up with mixing valves and the largest one being one inch. Do they make inch and a quarter?



What is a generously sized header, inch and a quarter?????



Can't believe how expensive the Hydraulic separator is I would think you could replace it with two air separators. You just would not have the capability of bleeding off any debris.



I am seeing this a little better now, but I would still have some questions.



Even the Taco looks like I could do it would just need to know chat components to use.

Zman

Boiler

The valves are referred to as ESBE valves.

The header should be designed for a flow velocity of less than 2 ft/sec. You can see the conversion on the "conversion factors" tab at the top of the page.

You can accomplish hydraulic separation using "closely spaced tees" instead of the hydraulic separator..

Carl

SWEI

Boiler protection valves

Danfoss (ESBE)

LK Armatur (imported here by MrPex)

Caleffi

cutter

valves

The ThermoBloc incorporates the boiler circulator, and thus

speeds installation and reduces installation space and

fittings. The ThermoBloc also includes thermometers that

indicate the temperature of the hot and cool inlet streams,

as well as the mixed temperature of the outlet stream. The ESBE valve is just a mixing valve that has different cartridges that can be put in for the application. The ESBE valve with the correct cartridge would be used on the oil boiler. if the oil boiler called for a ESBE valve it????? That is what I think I see.



Who sells the thermobloc valve? Or do you need to buy it from Caleffi.



I am not a HVAC person so this phrase totally confuses me, "The header should be designed for a flow velocity of less than 2 ft/sec".



Looks like there is a lot more to these systems than I thought.

SWEI

There's a lot more to doing them RIGHT

but that knowledge is getting more common as we replace rotted out OWBs.



ThermoBloc (Caleffi) and ThermoMat (LK)  combine a thermostatic boiler protection valve with a boiler circulator in a single packaged module.

cutter

doing it right

Where do you buy one of these valves?



ThermoBloc (Caleffi) and ThermoMat (LK) combine a thermostatic boiler protection valve with a boiler circulator in a single packaged module.

SWEI

Valve or integrated pump/valve block?

The valves are somewhat easier to find -- we usually have an LK 823 on the shelf.  Caleffi is widely available, but these are fairly new items for them here in the US.

cutter

flow velocity

I do not know how to figure out the header size to have a flow velocity of 2ft/sec. Can someone explain this or tell me where to find the information on how to do it? The piping the pump is connected to is inch and a quarter and the pump I use is a series 100 Bell and Gossett. I am guessing the flow slows down when passing through a larger pipe??? I was thinking of using black pipe for the headers, not copper. Is that a good or bad idea?