Lennox Crank Case Heater - HVAC - Page 2 - DIY Chatroom Home Improvement Forum

Go Back   DIY Chatroom Home Improvement Forum > Home Improvement > HVAC


Thread Tools Display Modes
Old 04-29-2011, 03:51 PM   #16
Join Date: Feb 2011
Posts: 94
Rewards Points: 75

Originally Posted by JJboy
Just to illustrate what can happen ...... adding oil, refrigerant, etc.

It won't be that bad. But beware it's still dangerous.


Hubcap626 is offline   Reply With Quote
The Following User Says Thank You to Hubcap626 For This Useful Post:
JJboy (04-29-2011)
Old 04-29-2011, 08:57 PM   #17
Join Date: Sep 2010
Posts: 135
Rewards Points: 75

If you are manually pushing in the contactor and before doing this verified you have power to it and it is not starting and blowing the c/b you may have a locked rotor in the compressor (ng).
If you have an ohm meter and clamp it around the feed wire going into the compressor and the amps double the name plate full load amps the compressor is (ng).
Make sure you check the wires at the compressor terminal to see if thay are all tight and have not fallen off the terminals.
When ever you are working on the condenser always wear eye protection and body protection such as gloves etc...

We had a job today with two compressors in one unit. One terminal was completely blown off of both compressor contactors, wires were burnt in several places, when we disconnected the wires from the compressors they checked good no grounds and no shorts. After we replaced the contactors and shorted wires we started both compressors and they both ran good.
Artco is offline   Reply With Quote
Old 04-29-2011, 09:04 PM   #18
Join Date: Sep 2010
Posts: 135
Rewards Points: 75

If you have voltage going to a crankcase heater you can use an infared thermometer to see if the crankcase heater is operating. Aim the laser beam at the heater and see what the temperature is. Checking amps will be really low if you if you check it that way.
Crankcase heaters should only operate when the compressor is not running. The mfg. May have a relay that energizes when the compressor shuts off to activate the heater. You have to know this when testing the heater
Artco is offline   Reply With Quote
Old 04-29-2011, 09:05 PM   #19
Hvac Pro
yuri's Avatar
Join Date: Nov 2008
Location: Winnipeg, Canada
Posts: 15,999
Rewards Points: 136

Burnt wiring happens all the time in ACs which vibrate and electric furnaces due to the constant heat/cool thermal expansion contraction on the terminals and vibration. The thing that gets guys killed or their eyes burnt from a welders flash when pushing in a contactor is when it it truly shorted and they don't check for grounding etc or even know that could happen.


"Cut it twice and it is still too short".
yuri is offline   Reply With Quote

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Similar Threads
Thread Thread Starter Forum Replies Last Post
Pilot on Williams millivolt wall heater goes out every 8 to 16 hours wornways HVAC 30 06-22-2011 03:29 PM
elevate electric water heater? crankbait09 Plumbing 18 04-18-2011 11:35 AM
Space Heater in Hot Water Heater Closet? MsMojoRisin Plumbing 0 02-09-2011 12:50 PM
Pressure drop across water heater, low hot water flow HVAC_NW Plumbing 2 01-17-2011 10:43 PM
Lennox Heater Light flashing Jake Spain HVAC 1 12-17-2010 09:32 PM

Top of Page | View New Posts


Search Engine Friendly URLs by vBSEO 3.6.1