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boiler zone wiring

3K views 2 replies 3 participants last post by  Grampa Bud 
#1 ·
i just installed a utia boiler,both zone pumps run but the thermostats don`t control right.the down stairs controls the temp.the boiler only has 2 thermostate screws.there are two magnetics that conrol the zone pumps and i`m not sure how to wire them. thx
 
#2 ·
boiler

Understanding the basic boiler circuit
It is important to first understand the basic operation of a boiler. There is always
a sequence of operation that must be followed. Most times on newer boilers you
can find this either on the inside of the front panel on the unit or in a manual
included with the boiler. A common sequence would go like this.
1.Thermostat calls for heat
2.Relay closes and energizes circulator and the control relay in the boiler
3.The damper motor is energized
4.When damper opens fully end switch closes control relay
5.Gas valve opens
6.Boiler fires and runs until temperature limit switch turns boiler off or
thermostat reaches desired temperature.

each tstat has to control a seperate circ motor, this is usually done with a zone valve or zone relay unit.
 
#3 ·
Is this a new system build or are you simply replacing the boiler in an existing system? Many of the newer boilers have a 'primary' circulator built into their basic plumbing, but you mentioned that you have two zone pumps making me think you have an older system with a pump for the first floor and a pump for the second floor or possibly one for the first floor and one for the basement. The TSTAT for a zone should call for heat through a dry closure (short) on its R & Y or T & T leads. From there the closure should provide a closure (short) to the T & T terminals of the motor/pumpcontrol relay for the zone that is calling for heat. All other zones with motor/pumpcontrol relays should be wired the same way. Also each control relay has a pair of X & X terminals. In order that any zone can call for heat, as it needs it, you have to wire those X's in parallel from first pump to last pump. Then wire the parallel X's to the T & T terminals on the boiler. If you have zone valves to truly isolate each zone, as well as the pumps, that is a different scenario. If you have installed a late model Utica with an internal circulator pump you have additional plumbing as well as wiring to do, but from what you have said this should take care of your situation.
 
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