How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site. Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask Phil Your Own Question
Phil, Mechanical Engineer
Category: HVAC
Satisfied Customers: 6022
Experience:  Retired HVAC/ Electrical & Boiler contractor. Industrial
Type Your HVAC Question Here...
Phil is online now
A new question is answered every 9 seconds

Have a traditional wall mounted Honeywell thermostat which

Customer Question

have a traditional wall mounted Honeywell thermostat which looking to replace with wireless Honeywell cm927. The system is a typical gravity fed std boiler (vaillant ecoplus 428). I have three wires; live, neutral and earth but not sure which goes where in the circuit marked N L L / A B C. Have used before in another house just can't remember the sequence."
Submitted: 2 years ago.
Category: HVAC
Expert:  Phil replied 2 years ago.
Hello,Tell me the voltage measured across all 3 combinations of the 3 wires. We can go from there in the morning. I start at 7 am west coast USA time.