Hydronic Boiler Splitting System Zones

[gus1203]

Hello all, I'm new in this site and I can use all the help I can get from you guys. It'll be appreciated.
My question is that I have a Weil Mclain boiler and currently has one zone for my basement and my first floor. What I like to do is install a seperate thermostate in the basement. Any one know what I need to do this? I've been looking at zone switching relays but what I don't understand is how am I going to control the 24 volt gas valve when both of the thermostats are calling for heat. Also do I need to add another circulating pump?

[sprintmj19]

It's kind of hard to see from here.

[snupytcb]

your best bet would be to call a pro in to help. this is not a diy job. you may have some piping to do so it will work.

[gus1203]

I know I have to do some piping and that is no biggy. I just need to get the controls figured out.

[ALASKAPF185]

Well the piping is no biggie, but do you know what size pipe you will need to deliver the correct amount of BTU's for your zone? Do you know how to repipe the primary loop and the secondary loop when you add this second zone to prevent the boiler from short cycling and or not over radiating the smaller zone? Are you gonna zone with a pump or zone valve? If you've looked into zone controllers then the wiring for the 24v section of it should be as easy as reading a legos instruction manual. whether it be zone valves or pump circs. Ah don't forget about reading the pump sizing chart correctly after you've calculated the head loss and don't forget the GPM equation, GPM=BTUH/(delta Tx499.8) and thats for 100% h2O in the system. I don't mean to sound sarcastic , but you should know what is done by a professional so he doesn't get a call back from the customer when the new zone is banging on and off, or its runs so loud now. Its too hot or runs forever to heat up. I would hate to see you post a problem thread 2 weeks from now........cheers.
check out some of this and let us know what product will best suit you.
http://flopro.taco-hvac.com/products...t_category=149 this is taco's boiler control and also check the zone controls
http://tekmarcontrols.com/multistaging.html check out the boiler 260 control and their zoning section some good info here

[gus1203]

Thanks for that info. I think i'm going with a taco switching relay looks like everything is

built in one panel. Im only adding 3 more radiators with 3/4" copper pipe.

[ALASKAPF185]

Radiators or baseboard fin tube ? You can add another pump but it will have to be the same as your current pump for the boiler and you will have to pipe the near boiler piping correctly with flow controls to prevent heating the other zone. IFC pumps or swing checks. The quickest would be to add 2 zone valves use the 1 pump and calculate the head loss to make sure that current pump won't be oversized for the now 2 smaller zones. You could create banging if you dont use a differential bypass valve or boiler bypass piping. Or add a Taco VDT pump to replace your current pump. Eliminates pump sizing errors. Our supply house engineer is very helpful with issues like this, give them the business and they want to make sure its installed correct. However boiler safety is more important, a simple blow off of the relief valve can cause some serious injury with 180 degree+ water. You really might want to look into a OutDoorReset since your gonna do some work.

[gus1203]

I'm using cast iron radiators and looks like I'm going to use a taco pump that I have as spare. This zone will be in the basement and won't be far from the boiler. Which switching relay brand do you recomend. I see many people use taco with taco zone valves. I just need two zones. Thanks for your help Alaska....

[ALASKAPF185]

Taco SR502 and we use honeywell zone valves because they are the most popular in our area for service and supply house stock. Taco's are good too. You won't need a relay with zone valves. Relay if you zone with pumps instead of zone valves.

[gus1203]

I was looking at the wiring diagram and I see that you need a second pump for the second zone combined with its own zone valve. How would I wire the second zone valves without the switching relay? I know I would have to wire the thermostats in parallel, but how about the 24v zone valve wiring? If I use one relay that means that both zone valves will open with either thermostat because I would tap of the transformer for the 24 volts.

[ALASKAPF185]

Your killin me here gus......Your last post is way off. You'll end up spending hundreds more than you need on equip. just put that towards a contractor doing it for you. Please tip him well if you stand over his shoulder and get your learn on. (thats a joke of course)

http://hvac-talk.com/vbb/showthread.php?t=718721&page=3
This is an example of zoning with pumps and a switching relay (which has its own 24v supply)


http://hvac-talk.com/vbb/showthread.php?t=725701&page=4
this with zone valves AND a "zone control relay". It makes wiring zone valves nice but it is unnecessary. You don't have to use the taco zone valve wiring relay. Also note the 1 pump. You do have to know about your transformers capabilities and with what brand of ZV's, a 2nd transformer is usually used for powering the zone valves alone, not the boiler's tranny.

[chamberlain]

I do not know how your pump station are set up,. but they make pumps with or with out checkvaves .you do not wont pumps coming on and pulling backwards through ather pumps.

[gus1203]

I will intstall the pumps on the return line. I'm still trying to figure out the controls. If any one has a diagram I will gladly like to see it. Thank you all.

[beenthere]

Sorry, this is NOT a DIY site. Please read site rules, thank you.