Welcome! Here are the website rules, as well as some tips for using this forum.
Need to contact us? Visit https://heatinghelp.com/contact-us/.
Click here to Find a Contractor in your area.
What's needed to wire 3 zone thermostats to Weil McLain water boiler?
JBerndt
Member Posts: 1
in Gas Heating
I am replacing my CGa-3 boiler with an almost identical one (but 30 years newer). The old boiler was always on (Thermostat circuit in boiler always closed) and the three circulators (each with their own thermostats and relays) worked independently.
I want to wire the new boiler to turn off when no thermostats are calling for heat (my understanding is that this is how it is supposed to operate). I can get that to work with a single thermostat/relay/circulator. The manual makes no provisions for multiple thermostats with independent circulators, but it says that if multiple zone valves are used, an isolation relay is required.
If I wire all three thermostats to the corresponding wires in the boiler, one thermostat would turn on all three circulators.
I want to wire the new boiler to turn off when no thermostats are calling for heat (my understanding is that this is how it is supposed to operate). I can get that to work with a single thermostat/relay/circulator. The manual makes no provisions for multiple thermostats with independent circulators, but it says that if multiple zone valves are used, an isolation relay is required.
If I wire all three thermostats to the corresponding wires in the boiler, one thermostat would turn on all three circulators.
0
Comments
-
You'll need three relays. One for each circulator, which will power the coil. Wire the normally open contacts of the relays in parallel and connect that circuit to the boiler T-T.
Or... control the boiler with an aquastat.Br. Jamie, osb
Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England1 -
A zone control panel is the way to go. It provides 24 vac to your zone valves isolating them from your boiler transformer. It provides easy connections and a light to show you what zone is calling for heat. Then it's two simple wires to your boiler to turn it on and off. I typically install taco zone control panels. Usually I buy one with an extra zone just in case a relay goes bad it's a quick 5 min fix of moving wires. Example if you have 2 zones buy a 3 zone panel.1
Categories
- All Categories
- 86.3K THE MAIN WALL
- 3.1K A-C, Heat Pumps & Refrigeration
- 53 Biomass
- 422 Carbon Monoxide Awareness
- 90 Chimneys & Flues
- 2K Domestic Hot Water
- 5.4K Gas Heating
- 100 Geothermal
- 156 Indoor-Air Quality
- 3.4K Oil Heating
- 63 Pipe Deterioration
- 917 Plumbing
- 6.1K Radiant Heating
- 381 Solar
- 14.9K Strictly Steam
- 3.3K Thermostats and Controls
- 54 Water Quality
- 41 Industry Classes
- 47 Job Opportunities
- 17 Recall Announcements