Coleman EB15B will not auto start

[kjosburn]

Hello,

I have a coleman EB15B and the blower will only auto start sometimes. The elemernts will heat, but no blower unless I manually put it to on.

Any ideas on where to start to get it fixed.

Thank You,

Keith

[Robert]

Hi Keith,

Most likely a bad sequencer. Look at far left end of each element coil for a spade terminal on a white ceramic insulator.

Test each one to metal ground for 120VAC.

One set of contacts from sequencer sends power to blower and one element. See if any of the elements are not showing the 120vac, if so, blower may not be getting it either if it is the M1 / M2 set of sequencer contacts.



Thanks,
Robert

[kjosburn]

Robert,

I have tested the items that i believe to be what you were talking about they all checked out at 120. Attached is a picture of what I tested to be sure that I tested the right items, any idea of what next.

Thank You,

Keith

[Robert]

Hi,

Did you do the tests when the blower was not working in Auto position ?

Need to test when blower is not coming on in Auto.

Another test is to look at wiring diagram to see the wire color for either heating or cooling speed, whichever you're using.

Then trace it to the first connection from motor, probably a molex connector plug, and see if it is getting 120vac to ground.

Then look for the other leg wire coming from breaker, usually orange or white, and see if it also has 120vac to ground.



Thanks,
Robert

[kjosburn]

Oops, I did not do them then.

Funny thing is, I have not had this problem since that day yet again. As soon as it happens again I will retest.

Thank You,

Keith

[Robert]

That will be fine Keith.


Thanks,
Robert

[kjosburn]

The gremlin is back....

Tested the items in the previous picture and the all had 120 and were on (bright red) and no fan, I also tried to manually push the fan and it did not start, however when I put the switch to on for the fan it started right up (high speed). I put it back to Auto and let it turn off the elements and tried auto again and it did not start again. I ended up turning off the circuit breaker in the heater for a few minutes and then turned them back on set the T-Stat to Auto and cranked up the heat and it now turns on automatically....

Any ideas this time around...

Thanks,

Keith

[Robert]

Hi Keith,

Read my earlier suggestion about the molex connector plug and see if you have the power there for the two wires to motor.


It works when you switch t-stat to Fan ON because that uses the fan relay to energize the blower in high speed, same as when using a/c.

For heat, it goes through the sequencer. Since you have the 120vac at the elements on both sides, the sequencer is working.

I'm thinking maybe a loose intermittent wire possibly in the molex connector.



Thanks,
Robert