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 Rick Mather Your Own Question

Rick Mather
Rick Mather, HVAC Technician
Category: HVAC
Satisfied Customers: 3634
Experience:  35 years experience, HVAC
12095340
Type Your HVAC Question Here...
Rick Mather is online now
A new question is answered every 9 seconds

Connecting a Honeywell R845 switching relay to a HoneyL7248C

Resolved Question:

<p>I'm installing a new Burnham Oil fired bolier that came with a Honeywell L7248C Controller.  The house has an existing Honeywell R845 switching relay to controll the second zone in the house. The wiring digram shows the leads coming from the #1 and #4 terminals on the R845 going to the ZC and ZR terminals on the L7248C.  However, there are no terminal srewon the L7248C where the labels are for the ZR and ZC contacts.  Is it possible that those terminals are shared with the B1 and L1 terminals next to them?</p>
Submitted: 3 years ago.
Category: HVAC
Expert:  Rick Mather replied 3 years ago.

Rick Mather :

Fig 5 and 6 clearly show those terminals

Rick Mather :

Fig 10 shows wiring for R845a

Customer:

Hi Rick,

Customer:

I agree, but alas, they do not exsist on box itself.

Customer:

they are labed but there is no terminal screw for Zr or ZC.

Customer:

on figure 10 on the upper left corner of the box for the controller is says "L7224"

Customer:

figure 12 shows "L7248L" which shows no terminal screw for ZC. I don't see any diagram specifically indicating "L7248C"

Customer:

here's a pic showing the labels for ZR and ZC but no terminal screws. Not sure how this this works but I need to step away for a bit. I'll leave this chat window open in hopes you can help.

Full Size Image

Customer:

your back!

Customer:

Can you see my problem?

Rick Mather :

The only choice would be to too get new aquastat that has the right terminals other wise you can wire r845 as just relay and hope boiler has enough heat to heat zone

Rick Mather, HVAC Technician
Category: HVAC
Satisfied Customers: 3634
Experience: 35 years experience, HVAC
Rick Mather and 5 other HVAC Specialists are ready to help you

JustAnswer in the News:

 
 
 
Ask-a-doc Web sites: If you've got a quick question, you can try to get an answer from sites that say they have various specialists on hand to give quick answers... Justanswer.com.
JustAnswer.com...has seen a spike since October in legal questions from readers about layoffs, unemployment and severance.
Web sites like justanswer.com/legal
...leave nothing to chance.
Traffic on JustAnswer rose 14 percent...and had nearly 400,000 page views in 30 days...inquiries related to stress, high blood pressure, drinking and heart pain jumped 33 percent.
Tory Johnson, GMA Workplace Contributor, discusses work-from-home jobs, such as JustAnswer in which verified Experts answer people’s questions.
I will tell you that...the things you have to go through to be an Expert are quite rigorous.
 
 
 

What Customers are Saying:

 
 
 
  • You did one super job of explaining to me everything there is to know about this fridge. I'm looking forward to asking you questions in the future. Jimmy Bagley, IA
< Last | Next >
  • You did one super job of explaining to me everything there is to know about this fridge. I'm looking forward to asking you questions in the future. Jimmy Bagley, IA
  • Wonderful service, prompt, efficient, and accurate. Couldn't have asked for more. I cannot thank you enough for your help. Mary C. Freshfield, Liverpool, UK
  • This expert is wonderful. They truly know what they are talking about, and they actually care about you. They really helped put my nerves at ease. Thank you so much!!!! Alex Los Angeles, CA
  • Thank you for all your help. It is nice to know that this service is here for people like myself, who need answers fast and are not sure who to consult. GP Hesperia, CA
  • I couldn't be more satisfied! This is the site I will always come to when I need a second opinion. Justin Kernersville, NC
  • Just let me say that this encounter has been entirely professional and most helpful. I liked that I could ask additional questions and get answered in a very short turn around. Esther Woodstock, NY
  • Thank you so much for taking your time and knowledge to support my concerns. Not only did you answer my questions, you even took it a step further with replying with more pertinent information I needed to know. Robin Elkton, Maryland
 
 
 

Meet The Experts:

 
 
 
  • gotoman for ac

    HVAC Technician

    Satisfied Customers:

    4657
    51 years of experience install design and repair of all makes and models of AC
< Last | Next >
  • http://ww2.justanswer.com/uploads/SE/ServiceTechRus/2012-6-7_2119_056.64x64.JPG gotoman for ac's Avatar

    gotoman for ac

    HVAC Technician

    Satisfied Customers:

    4657
    51 years of experience install design and repair of all makes and models of AC
  • http://ww2.justanswer.com/uploads/AL/alumalite/2012-5-10_234018_shutterstock506249951forJA500.64x64.jpg Phil's Avatar

    Phil

    Mechanical Engineer

    Satisfied Customers:

    3888
    Retired HVAC/ Electrical & Boiler contractor. Industrial
  • http://ww2.justanswer.com/uploads/skibum0101/2008-12-16_015819_just_answer.jpg Rick Mather's Avatar

    Rick Mather

    HVAC Technician

    Satisfied Customers:

    3132
    35 years experience, HVAC
  • http://ww2.justanswer.com/uploads/RY/Rygis20/2011-5-7_3143_DSC5324.64x64.JPG Matthew's Avatar

    Matthew

    HVAC Technician

    Satisfied Customers:

    1994
    14 years experience in the HVAC field of service, installation, Manual J & D calculations
  • http://ww2.justanswer.com/uploads/KE/kentguidry/2011-9-26_214316_0059.64x64.jpg Kenton Guidry's Avatar

    Kenton Guidry

    HVAC Technician

    Satisfied Customers:

    962
    12 years install/service experience.
  • http://ww2.justanswer.com/uploads/solarman1947/2009-12-13_223915_phpkKBcXq_c2PM.jpg Rick Ridley's Avatar

    Rick Ridley

    UK Heating Engineer

    Satisfied Customers:

    871
    Retired But have had 30 years on the tools, Ex CORGI
  • http://ww2.justanswer.com/uploads/Ironheadfan/2009-12-18_222416_pump_005.jpg Tom's Avatar

    Tom

    HVAC Technician

    Satisfied Customers:

    770
    16+yrs HVAC/R service. Residential Commerical Industrial