Baptismal pool boiler set up..

Ah yes, variable speed salvation. I'm guessing though, that it happens all at once. But what do I know? I'm only a plumber.

I'm not religious. I just like the stories. Besides, I only know "Hail Mary, full of grace", then I'm lost. Can I do 20 of the Lord's prayer instead?

For Cripe's Sake! @HVACNUT

That would be Jesus Cripe, Son of Gosh, along with Great Cesars Ghost, of the Roman Church of Holy Moley. For those that are not of this faith

This is what I come up with for your boiler system

However, if you feel the need for overkill, install the bypass and use manual valves to get the return water temperature where you need it. The boiler protection valve will make the adjusting automatic if you believe you need it.

The parts list is above and the boiler protection valve can be found here: Caleffi 280966A-1, but I really believe it is overkill. But if it is in the church's budget, then go for it. I try to keep the cost as low as possible when it comes to church.

Agree, but @Mail4tommo said above, "The customer is fixed on a boiler set up." I'd at least try to push an indirect coil.

I also don't see the point of using a circulator pump instead of just filling it with water that goes through a water heater. Use a tempering valve to get it the right temperature.

This is being made way more complicated than it needs to be.

The makers of baptisteries also offer electric in line heaters (usually made by Little Giant) specifically for this purpose. They’re usually 4-5kw and can easily heat the average sized baptistery over night.

I’m a Baptist and I’ve installed or repaired several over the years.

Ed, the customer is definitely wrong in this case, probably from the misconception that they need a boiler to do the job.

Baptist churches are democratic in their decision making (sometimes too much so) and usually a committee makes these kind of decisions. The problem is that the committee is quite often a pool of ignorance putting forth erroneous opinions.

It has well been said that a camel is a horse that was put together by a Baptist committee.

Did I mention that I’m a Baptist?

I hear ya' @Ironman Cape Island Baptist Church In Cape May, NJ was my customer for many years. I was the oil company's service man (by recommendation) and when they needed a new boiler for the church, I wanted the job. I also knew that there was a committee of ignorance putting forth erroneous opinions very intelligent people, and I didn't have time to answer 20 questions, over the phone, after each member read the proposal, so I didn't mail the proposal. I requested that I be invited to a committee meeting as a guest speaker to give them the proposal in person with all decision makers present.

I then prepared three options with a power point presentation explaining the features and benefits of each choice. After the presentation, I answered questions for the group and then left the meeting with the thanks of the committee and my sincere thanks for them to make time for me at their meeting. The next day I got the call that I was awarded the job and selected the middle cost proposal.

And I remember seeing that baptismal water heater in the boiler room standing about 3 ft tall. All copper coils with a 60,000 BTU burner under them. I thought to myself when I looked at it, "I would hate to have to vacuum clean soot out of that mess of copper"

That's why I thought the electric spa heaters were the way to go.

I got a PM from @Mail4tommo about another project. He stated:

I have to go to a customer's here shortly and measure up the windows and btus of all the appliances, I convinced the customer that it would be a good idea to put motorized louvers and Boiler room for the fact of potential pipe freezing and the tenant that is directly above the windows and constantly has a freezing cold floor. I said it would definitely help with that (not necessarily get rid of the cold completely), and also it would help keep the elements out... So I get to figure out how to wire that in the safety circuit.

Also the same boiler I get to figure out how to wire in a vent damper for an LG B7. I told them it's constantly sucking the heat right off the boiler right out the chimney every time it's in standby I told them it would help their efficiency dramatically. So I get to figure out the wiring for that too.

I was wondering if the same motor with the built in safety circuit cant be used on both the combustion air louver and the vent damper. this is the auto vent damper needed Field Control 12" Vent Damper. and the combustion air louver could be this one: https://www.greenheck.com/products/air-control/louvers/operable-louvers/adjustable-operable-louvers/ead-635 . the actuator motors need to be different though. Here is the sequence of operation:

• Call for heat
• Louver actuator opens combustion air
• End switch proves open
• Boiler circuit enables
• Vent damper opens (its own motor)
• Vent damper end switch proves open
• Boiler fires

Doesn't NFPA 54 allow for indoor combustion air use as long as the boiler room volume is at least 50 cubic feet per 1,000 BTU/hr? Is the boiler room in question too small for that?

Fortunately our old condo building basement is big enough and leaky enough that we don't need outside combustion air.

LGB 7 is a comercial boiler.

Do they make a commercial version of the Fan-in-a-Can for a one million BTU boiler?

When was the last time you saw a commercial boiler room that was 2,000 sq ft with a 10-foot ceiling? I believe this boiler is just under one million BTU and is in a room no larger than 10' × 15' with a 11-foot ceiling. That is about 1,650 cubic feet. That is considered a confined space by NFPA 54.

The Field Control is it's own thing, wire it up per the IOM; but the Greenheck you linked to is just a plain old damper with an actuator (if you order it with one, otherwise it's field-provided). They don't come with any kind of wiring diagram more complicated than "power these wires to open, and here's your end switch". Order the right actuator and it can be connected in parallel with 2 & 4 of the Field Control to open the damper, and the end switch can break 3 going to the TH terminal on the gas valve. They'll both start to open at the same time, and the gas valve will stay off until both are open (or, at least, the end switches make). You'll save some time vs opening them one at a time.

I suppose it's possible that there could be some strange interaction with the internals of the Field Control that would make my plan not work, but I can't see anything wrong with it, judging by the wiring diagram in the IOM.

Yes, but if you ccan't open the damper, you can't safely fire the boiler, so it's moot.

And don't use 120 volt actuators, use 24 volt actuators. You'll be glad you did.

Everyone is reinventing the wheel here.

The Greenheck unit can use a 24 VAC actuator motor that opens when there is a call for heat from the thermostat. The end switch from the damper actuator, once fully open, will close and send a signal to the boiler.

When the boiler receives the call for heat, the sequence of operation is as follows: the vent damper motor will open. Once the vent damper is completely open, its end switch will enable the ignition system, and the burner will light.

Once the burner is lit, the boiler can heat the building until the call for heat is satisfied.

in short:

• Call for heat
• Louver actuator opens combustion air
• End switch proves open
• Boiler circuit enables
• Vent damper opens (its own motor)
• Vent damper end switch proves open
• Boiler fires


About taking a ignition control off the boiler and replacing it with an ignition control that is equipped with a vent damper 6 pin molex plug I have this to say:

The Weil-McLain LGB series is furnished with multiple factory wiring configurations to comply with various codes and standards, including Factory Mutual (FM), CSD-1, and others. In these boilers—particularly the larger models—the burner system may consist of multiple gas valves and corresponding ignition controls operating in stages. Because of this, a vent damper cannot simply be added by replacing or modifying a single ignition control.

From a safety and code standpoint, the vent damper must be interlocked so that all burner circuits are proven safe before any ignition can occur. If only one ignition control is tied to the vent damper proving circuit, another stage could still energize and fire into a vent system that is closed or partially closed. This creates a serious hazard, including flue gas spillage and the potential for carbon monoxide exposure.

Therefore, any vent damper installation must be integrated into the common safety circuit so that no burner—at any stage—can fire unless the vent damper is fully open and proven. Anything less does not meet the intent of NFPA 54 or CSD-1 safety requirements and should not be considered an acceptable installation.

in this diagram there are 4 ignition controls to operate two different sections of the burners. the only common area for the vent dampera end switch is in the Line Voltage limit circuit before it feeds two separate low voltage control transformers.

This would make it impossible to follow the 24 volt wiring that Field controls provides with the 12" vent damper. To know what to do here I would request that the actual wiring diagram from the boiler be provided. Hopefully it is from a series 1 LGB 7 that has simple wiring like a residential boiler system. With the actual wiring diagram the process will be easier without guesswork.