You are here:

Heating, Air Conditioning, Fridge, HVAC/Gas Boiler Zone Valve & aquastat wiring


To start, ill give you a quick synopsis- have a run away boiler, keeps running (although high limit does shut it down). Pump continues to regardless of thermostat input (in fact their disconnected). Transformers all work, 24V. Both zone valves  (honeywell 8043e1012 )stuck open even with no power (i will replace the heads as i did a few years ago). The aquastat (honeywelll L8148J )i will replace as well.

This is where it gets fun- aside from the wiring inside the awuastat, my old man come's over (hes a combination of Ralph Cramden and Homer simpson) and immideately unwires all the zone valves, etc which was a typical rats nest from the get go.

Wiring these back up- each zone valve has four wires (2 red, 2 Yellow). I assume one wire on each zone valve must be a common ground from the transformer, one must be a switched hot from
The thermostat to activate the motor  (in fact the transformer/thermostat circuit wires are still intact, i will just need to identify which wires are for which thermostat). That leaves me with two more wires, which i assume (any combinationcof which) would go to to the aquastat to fire the boiler and turn the pump on.

Which wires do what?


In regards to your boiler not shutting down, to me your wiring somewhere is not correct, in regards to the zone low voltage wiring ,to me it would be much easier if you downloaded from the web a basic wiring configuration similar to yours and wire your system accordingly. It does not have to be the same brand as yours as long as it has the same type of controllers  

Heating, Air Conditioning, Fridge, HVAC

All Answers

Answers by Expert:

Ask Experts




40+ years diversified experience.An HVAC/Refrigeration Self Employed Contractor since 1986. NATE Certifield. Answer questions pertaining to Residential and Commercial Air Conditioning , Warm Air Heating, Heat Pump systems.Mechanical and Electrical troubleshooting of these systems.Be as detailed as possible when describing problem.Packaged unit or split systems.No appliance questions.


Installation and Troubleshooting, Mechanical and Electrical, in following areas, Refrigeration ( Walk In and Reach In Coolers and Freezers ) Commercial Roof Top and Packaged Heating/Cooling ( Natural Gas,Propane, Electric, and Heat Pumps ) Computer Room Air Conditoning Systems,Commercial Residential Packaged and Split Systems Air Conditoning and Heat Pumps.Warm Air Oil , Natural and Propane Gas Heating systems.

Graduated from Private Technical School in 1975. An HVAC/Refrigeration Contractor . Have Unlimited Heating/Piping and Cooling Contractor License.Limited Sheetmetal Contractors License.NATE Certifield. York Certifield Master Heat Pump Technician 1986. Served 33 years combination Active Duty Air Force , Air Force Reserves and Air National Guard in the HVAC/Refrigeration Shop/Mechanical Shop. Troubleshooting/Installing HVAC/Refrigeration Equiptment Worldwide. Retiring in 2003 as a Senior NCO ,and a Mechanical Superintendent.

©2017 All rights reserved.