Combining zones

themow

I have a weil mclain  cgi-7 boiler. It was wired and setup for three zones. Two on the first floor and one on the second floor.  I want to combine the the 2 on the first floor to one zone controlled by the one thermostat.  The supply exiting the boiler is 1" copper going thru a taco and then under the house where it splits to the two zones and reduces to 3/4". I am wondering if the 3/4" will be big enough to supply both zones which will now be one zone with heat. My plan was to intercept the supply and return of the one zone where they cross one pipe from the other zone.  The zone is just a one room zone that is 25x20 with baseboard on 3 of the walls. Thanks alot

Al Letellier_21

combining zones

You have to do the math to determine if it will work. You didn't give us the load or amount of baseboard in the zones but as a rule of thumb only 60 feet of BB on a 3/4 loop, and that is pushing it......do the math work and you can get it very close.

Big Ed_4

Wired in the Two

Why don't you just wire in the two zones so they both run at the same time ?

icesailor

Combining Zones:

They ran 1" for a reason.

I don't understand why you want to combine them into one. Most jobs I run into wish they had two zones. There must be a reason they did that.

themow

more effective?

I want to combine the zones because they are both on at the same temp all the time and i feel that the boiler may have less run time if they were combined. Im not concerned about minor temp differences in the rooms. If there are no issues to just wiring the zones together i will surely take that route since its much easier than rerouting the pipe.

As far as the setup goes its 3 zones controlled by honeywell motorized valves with one circulator pump. 



 i am trying to combine the two zones on the right into one controlled by the middle valve. I plan on cutting the white and red coming from the tsat im deleting. I was going to put a jumper from the TR middle valve to the TR on the one im adding. while leaving the white in the TH position on the valve since it comes from the control box? transformer?? . Its white runs to the Th on all three valves.

Thanks alot guys

themow

vale

So am i on the right track? do i need to bother with one of the end switch wires?

icesailor

A plan to combine zones:

You sound like you have a plan. Most want all the zones they can get for even heat control.  And when you get the whole house on one thermostat because you heard that it is better this way, go for it. If it doesn't work, you can always reconnect the thermostats.

Meanwhile, I am enjoying my 5 zone valves that keep the various areas of my Cape at the temperatures I want where I am at a point of time. I could care less how often my boiler runs. As long as the circulator is running and the burner cycles when it needs to.