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.
McDonnell 67 Boiler Wiring
Options

a1will
Member Posts: 23
I stupidly detached my LWCO without taking pictures of what wires were landing where. I have a Mcdonnell 67. There is an autofeeder and the original pressuretrol (American Standard built in 1964). The PO's have the wiring a bit of a mess with an electrical tape and wingnuts in there. I haven't really decifered what they are doing, but I would guess they used the electrical tape to make a jumpered connection like I see on some of the wiring diagrams. I have the auto feeder wired on terminals 3 and 4, and that works properly. I am having trouble understanding how to wire the switches on the lwco and pressuretrol. I think I am just fundamentally not understanding how the switching should be setup as opposed to anything goofy going on. Anyone have any easy to digest diagram/pictures? I have looked at the LWCO wiring diagram and this link http://wea-inc.com/pdf/MMwiring.pdf and understand I need to make a series circuit between the 3 points (lwco, pressuretrol and finally gas valve) but think I am just being especially dense today. I've wired up plenty of switches in my house wiring but for some reason can't wrap my head around this.
0
Comments
-
Any solutions yet? Just wondering..... Steam can cause quick damage to skin if not totally understood! I just want you to be careful and get on site help from professional SteamHead... The Q; is concerning in and of itself...... All due respect.
Mike T.0 -
Categories
- All Categories
- 87K THE MAIN WALL
- 3.2K A-C, Heat Pumps & Refrigeration
- 57 Biomass
- 426 Carbon Monoxide Awareness
- 116 Chimneys & Flues
- 2.1K Domestic Hot Water
- 5.7K Gas Heating
- 109 Geothermal
- 160 Indoor-Air Quality
- 3.6K Oil Heating
- 70 Pipe Deterioration
- 991 Plumbing
- 6.3K Radiant Heating
- 389 Solar
- 15.4K Strictly Steam
- 3.4K Thermostats and Controls
- 54 Water Quality
- 44 Industry Classes
- 48 Job Opportunities
- 18 Recall Announcements