Replies

1. 
   Davo304 | Jan 28, 2009 08:39am | #1

   I don't know very much about electric furnaces, but when you installed the thermostat, was it installed dead level?  They need to be level.  Also, does the thermostat you installed contain an "anticipator"? If not, change out the thermostat to one that does contain one.

   If it has an anticipator, did you check to see if amperage calibration is set correctly?  The furnace manual and/or a label found on the service panel should indicate what the amperage setting for your thermostat circuit should be. If using a low voltage round or a rectangular thermostat, remove the cover plate off the thermostat and locate the anticipator indicator. On a round thermostat, the indicator is found near the bottom, below the temperature dial...it's a tiny scale with a small arrow pointer.  On a rectangular thermostat, it's a thin metal strip located in the center of the dial.

   Normally, a faulty thermostat ( or an unlevel thermostat) is the culprit behind a furnace that does not shut off properly.  A faulty anticipator or uncalibrated anticipator will cause the furnace to short cycle.  Sooo, it's very possible your trouble lies somewhere with the thermostat/anticipator.

   If both of these things check out OK, then you need to check the thermostat wiring connections insde your furnace located at the control terminal block. Make sure you disconnect power to the furnace before opening it up and tracing for loose wires.

   If all connections at the terminal block seem oK, then check to see if any fuses are shorted out. The fuses should be near the furnace's "step-down" transformer. If fuses are OK, then best advice I can give, is call an electrician. 

    

   Hope this helps.

    

   Davo

1. 
   mikeroop | Jan 28, 2009 06:11pm | #3

   Thanks the thermostat doesn't have mercury in it. It's electronic but is still level. Checked all the wiring and fuses every thing appears ok. like i said if i turn off the breaker let it set for awhile and turn it back on it works fine for awhile so it's like something is getting hot and sticking. Hvac man said he thinks my stat wire is shorting out. but i ask why does it work a couple times after i turn the power off?

1. 
   john7g | Jan 28, 2009 06:32pm | #4

   sounds more like a sticky relay than any wiring issue. 

2. 
   splintergroupie | Jan 28, 2009 09:19am | #2

   Google says it's the fan relay or sequencers.

   I've no idea what i'm talking about, lol, but that's a place to start. (I googled "electric furnace won't shut off".)

3. 
   Clewless1 | Jan 30, 2009 04:45pm | #5

   Tend to agree w/ John ... but am no expert. Not much rocket science here. The low voltage switch (the stat) controls whether the furnace should come on. Assuming it is functional, then your relay is the next "switch" that the stat activates.

   I'm assuming you mean the heat is stuck on ... not just the fan ... although they may be controlled by the same devices. You are overheating, right?

4. 
   basswood | Jan 30, 2009 04:48pm | #6

   I think my renters would just open a window and let the furnace run. :o)

5. 
   DanH | Jan 30, 2009 06:06pm | #7

   Probably fused relay (sequencer) contacts.

   The modern conservative is engaged in one of man's oldest exercises in moral philosophy; that is, the search for a superior moral justification for selfishness. -John Kenneth Galbraith
1. 
   mikeroop | Jan 31, 2009 07:58am | #8

    well guys thanks for all the replys, but the tenant called the other night and said it had a burning smell and then no heat just cold air went over and found a wire to one of the coils burnt into fixed that and she said it has worked properly ever since. who knows?!

1. 
   DanH | Jan 31, 2009 04:18pm | #9

   Yeah, the overheating wire was likely throwing off the thermally-operated relays.Be sure to check that connection several times over the next few days and weeks, though, since the connector may be punk and you may get another burn-out in the same place until the device is replaced.
   The modern conservative is engaged in one of man's oldest exercises in moral philosophy; that is, the search for a superior moral justification for selfishness. -John Kenneth Galbraith

1. 
   mikeroop | Feb 01, 2009 05:35am | #10

   i made a whole new set up ,new connectors, wire and all :)

1. 
   DanH | Feb 01, 2009 05:52am | #11

   I was speaking of whatever the connector was connected to -- a screw terminal or whatever. Have seen several times where the wire would keep burning out at the connector, and it would keep doing it until the device was replaced.
   The modern conservative is engaged in one of man's oldest exercises in moral philosophy; that is, the search for a superior moral justification for selfishness. -John Kenneth Galbraith

6. 
   ponytl | Feb 01, 2009 06:12am | #12

   look at the magnetic contactors... the contacts will weld together...   a simple 2 pole contactor 30-50 amp is pretty generic...  think i pay about $15 for em...

   p