zone circulators or zone valves?

heatingFun

I am planning adding another two zones on my 1600sqft one story ranch house. We converted from oil to gas 3 yrs ago, the boiler is big enough for this update.



I don't know what is the current one zone setting. It is not a Monoflo setting. It is not a reverse return setting. It is may be a primary/secondary setting but I cannot convince myself about this. Anybody can give a name to it?



My original old oil boiler was located at another end of the system. I just found few days ago, the plumber may switched the supply and return by accident when he connected the system into the new boiler. Now all the air purge valves on individual CI baseboards are on the water in side. These valves should be on the water out side. Am I right?



That may can explain why he connected  the supply and return together at the new end of this system. what do you think? A drawing about my existing heating piping is attached.



I am planning to change it to reverse return setting during the process of adding zones. The 3 zones will be bedroom zone, family and living rooms zone and basement zone.



Based on my existing set up here, should I use zone circulators or zone valves? There is a black 007-F5 circulator for the existing one zone system now. No flow check valve was installed. 



I have two options:

1. add another two zones with separated zone circulators by using 007-F5-IFC and replace the existing 007-F5 with a new 007-F5-IFC;

2. use zone valves for all zones by keeping the existing 007-F5.



There should be no difference on switching relay choice for zone valves and zone circulators?

Alan (California Radiant) Forbes

Looks like

you have a 2-pipe, direct return system and yes, changing it to a 2-pipe, reverse return system is a good idea.



Zoning with pumps or zone valves is a personal preference. I like zone valves, preferably Caleffi or Danfoss. They seem to last longer than others. And the controller for pumps is going to be different than for zone valves. The excellent Taco brand offer "ZVC" models for zone valves and "SR" models for pumps.

icesailor

Secondary/Primary:

I don't think I have ever seen it done like that before. .



It looks like a Secondary/Primary system. The heating piping to the house is the primary loop and the boiler loop is the secondary loop through the two closely spaced tees connected to the primary (house) loop.



Interesting.

Nice job on the blue PEX.



I looked at the I/O manual for the Alpine Boiler. That's how they show it. None of the boilers I have ever done show it piped quite that way, and it must work. But a closely spaced tee is a closely spaced tee.