looking for resources

[Branden Kruger]

Looking for good resources & how to's to install a used Central CL4436. The boiler will supply 1600sqft of infloor heat, a modine and water heater. Looking to find the best was to supply these multiple heat sources. On line diagrams or corespondance. The used boiler I purchased supplied heat to a home and an external garage.

Thanks in advance.
Branden

 

[Clarkbug]

Branden,

Welcome to Hearth!

Go back to the main "Boiler Room" forum, and read through the posts that are at the top of the page. Lots of good info as far as design, piping things, general good ideas, etc.

That should be a great starting point, and then you can come back here with more pointed questions/comments/etc.

 

[Branden Kruger]

My main question is how best to run the (3) items I plan to supply boiler heat to. I have viewed many different diagrams on and off site. I have found some very useful info on this site in other postings. Below is a basic run down of wha tI have and my plan. By all means, please add any advice you may have.

I have a used Central Boiler CL4436, 250K BTU, 185Gallons. I have 1600sqft of radiant floor space to heat via (7) loops of 1/2 pex. Well insulated floor with 2" foam,underneath and along outer perimeter. I plan to use 60 gallon domestic water heat and I also have a ceiling mounted water to air modine. The radiant floor and water heater with run constant. The modine will be on demand if called for. The shop is well insulated 6" walls and will have a 11ft ceiling height.

I would like to use (1) pump if possible. The unit I bought did supply heat to a home and to an external garage. One pump was included and will push the water from the boiler. The unit will sit about 24" max below grade, lines trenced about 48" below ground and insulated within a 3" foam board box sprayed with expandable foam. I live in west central Wisconsin and have heard from multiple people to go 3 to 4 feet under (frost line). Non barrier pex will be used. I'll come thru the wall and my plan as of now is to tee off and supply the water heater and than modine on one end and radiant floor on the other. Returns will come together and tee back to the boiler. Basically using the diagram you find for the Dual System In-floor radiant/forced air on the Central Boiler website and brochure.

Here is where I am confused and it deals with the set up of the used boiler. The guy had it installed and he didn't know much on how it was set up to work. They have a pump located in the unit and everything labeled. Below is a picture. The supply side has (2) taps going into one pump and label house supply, That's it. The return side has the house return coming back, teeing off and then a ball valve is labeled garage supply on the outboard side (going back away from boiler) and house return in the inboard side (back into boiler). Then it has its own garage return line going back into the boiler. I assume he had another pump in the garage pulling from this tap for the house return line? But I have know idea and its confusing me and haven't seen this set up anywhere on any diagram. Thinking it might be some trick of the trade.

Is there a better way to do what I attend to do? I've read on this site that multiple pumps are the way to go. I don't think I need to use multiple pumps but do I use two pumps located in the boiler? If so, what would be the best way to divide the heat sources. I'm mainly concern with my in floor and don't want any chance of upheave.

Like I said, any feedback is welcomed and don't worry about bruising my ego. I am a do-it yourselfer, but not a pro!

Thanks,
Branden

 

[Clarkbug]

Branden,

Much thanks for all of the good info. Its good to know what you want to do, always a good thing. Ill offer my input, and Im sure others will be along with further thoughts/insight.

The multiple taps on the boiler itself are meant for if you want to feed multiple buildings simultaneously. I believe there are two or three supply/return taps on the boilers. If you are feeding the floor, water heater, and heater in one building, you only need one of them. You can remove the other piping and put plugs in them.

Centrals are an open system, so you wont build any pressure in them, or if you do it will vent itself. That pump on the boiler is going to run 24/7 as long as you fire the boiler. You want that water moving all the time to prevent freezing, and also to make sure that you always have hot water in the house. The controls on the boiler will modulate to maintain a HW setpoint that you pick. So you always want the water circulating to try and keep it up to temp.

Having said that, I think you are going to need at least one other pump.

You can pipe the boiler so that it always flows through a side arm on your hot water heater, and then through the modine (assuming that it just cycles the fan, and that there isnt a control valve on the coil). To feed your floor heat, I would add a plate and frame Hx after the other two heat sources. Your floor wants colder water temps, so you can use the colder water without any penalty. Also, you will want to have a scheme to control the temps going into the floor, so on the outlet of the Hx, you would put another pump and a means of controlling the mixing. Im thinking thermostatic valve. This way you can pump the floor loop separate from your boiler loop, and have control there.

Make sure to add a tempering valve to your hot water heater if you do this, or you can scald yourself pretty easily.

Hopefully some of this makes sense (at least it does in my brain).