Coleman Evcon EB17B Serial#950531147

[Roon81]

My furnace has been blowing , but no hot air coming out (while it was doing this the green light was on , and the red light was flashing). I could usually reset the breakers and it would heat for a short while. I could feel the elements heat up and then the fan would kick on , but the heat wouldn't stay on long. This went on for a few days, and now the furnace will not turn on at all. When I flip the breaker the green light flashes once , follwed by a red light flashing once and that's it.
Does this sound like the sequencer ?

I updated to a digital T-stat apprx 6 months ago , but I do not think that is the problem.
And I have no obstructions in the air path.

[Robert]

Hi,

Could be several things. Need to check for voltage at blower motor and elements to find out exactly where the interruption in power is at.



Thanks,
Robert

[Roon81]

Robert,
This post run a little long sorry.

Here are the readings I took last night, with the furnace on an theT-stat calling for heat.

Sequencer-
M-1 , M-2 , M-3 , and M-5 reading 120 vac
M-4 seemed to come on and off , and I was losing power to the middle element.
No reading on M-6
Also no readings on the H terminals.

Top Element - 120 on both L & R (but did not seem to be heating)
Middle Element - 120 on both L &R (when M-4 would supply ) ( but seemed to not heat)
Bottom Element - 0 reading on the L & 120 up to the limit swith

Relay -
120 on the 5 and 2 input terminal
No reading from T-stat or to transformer
I can't remember the reading out to the the blower (i think 1 was hot , and 1 not)

Transformer- 120 vac from breaker
No reading from sequencer or T-stat

Does this help any ?

Also , Here is the order of events on the downfall of this furnace .
First - No Heat , but the fan wold blow and the blend air box would light up
Second - a few days later - No Heat , No Fan , but the blend box was still lighting up
Now - No heat , No Fan - No lights .

Hope you can help. Zac

[Robert]

Hi Zac,

Go to transformer and test Primary-Line side for 240vac across the two terminals.


Then go to other side, Secondary-Load side and test for 24vac.



Let me know what you get.



Thanks,
Robert

[Roon81]

Robert,
When I went to check the transformer I noticed my Klein Voltmeter only read 48 vac on the top leg of the circuit breaker. The increments skip from 48 to 120 on my meter. This was probably the case last night as well. Here is what I did. I unplugged all of the wires at the bottom circuit and moved the top wires down to the bottom breaker.
After this, the furnace would kick on , but it would throw the breaker back in the box at he rear of the house. This is the first time I noticed this happening.
Now I have unplugged the middle element and it does not kick off. I think I am getting a little heat off the top element and all seems to be working well.(except the two unplugged elements and top breaker) This should help tonight.

I think I have a bad top breaker , and I also think the middle element is shorting out. Does this sound right ? Also do you sell a kit with the short wires that run to and from the elements ? I have broke the ends of two.

Thanks for all the help, Zac

[Robert]

Hi Zac,

I cannot help you unless you are willing to answer my questions. Test the transformer.



Thanks,
Robert

[Roon81]

Yes, now that it is running from the bottom breaker.

[Robert]

Hi Zac,

It needs to be put back the way it was originally and then test the transformer as instructed .




Thanks,
Robert