Coleman EB20B

[stwkmoore]

I have a Coleman EB20B, this unit came with my used double wide. At first when I turned the power on it would do nothing. I do have a wiring diagram and soon found someone had moved a lot of wires around. mostly on the heating elements. I put the wires back to where the diagram said they should be turned the power on and the blower came on. All it does is blow cold air. My unit has electric heating coils. I can set the T-stat where ever, off, on heat and this has no change on the unit blowing cold air. The T-stat seems to have no control over any thing and at this point I am lost.
The T-stat cover has Evcon 7990-368 on the inside, also type IC26-15, made in China, rev b, 156-2978. I hope this means something to you because it don't to me.
My unit also has AC but I am not using it nor is it connected at this time. I have a red, green, white and yellow wire coming from the t-stat. I think the yellow goes to the AC unit outside and the red and green connect to make it heat. Also I think the white is common.
Could you please point me in some direction to check.

[stwkmoore]

I took the fan relay cover off and noticed the contacts are worn and the spring is very lose, makes me think it is simply worn out. Should it not kinda snap back and forth?

[stwkmoore]

with or without power terminals 5 & 6 are open on the fan relay part #3110-3301, which makes me further think the fan relay is bad.

[stwkmoore]

1 of the power feeds to the heater coils reads 90 volts, but if I take the wire off going to the fan relay all read 120 volts. Are both load outs on transformer 3300-3861 suppose to be 24 volts? Mine are not, only 1 is the other is 0.5 volts.
I now really feel like a dog chasing its tail. I have no doubt the blower relay is bad, but would that stop the heating coils from working?
I am now way over thinking this..........

[Robert]

Hi,

Blower relay should always be closed across 5 and 6 unless 1 and 3 has 24vac applied to it for a/c mode or fan on continuous mode.


Sounds like the blower relay and the sequencer may be bad. Also, check the crossover duct underneath home to ensure it has not come loose, become kinked, laying on ground , etc.


Sequencer # 3120A3571

Blower Relay # 3110 = 3301


Both can be seen and ordered through PayPal from this page :

http://www.mobilehomerepair.com/ColemanElec.html



Thanks,
Robert

[stwkmoore]

I have ordered both from you. And I await delivery. But to answer your question that you ask at the bottom of your reply.
Some people are Humbly Grateful, while some are Grumbly Hateful.................... Which one are you ?

I am both, just depends on the day. lol

[Robert]

Hi,

Too much energy expelled being hateful. All it takes to be grateful is a smile.

Thanks for ordering with us.


Take care and best wishes,
Robert

[stwkmoore]

I have replaced both Sequencer # 3120A3571, Blower Relay # 3110 = 3301. But Still the fan blows constantly and no hot air. I did note the air got warmer than cold. Would a bad t stat cause this? If so can I jump the red wire and the ? wire to make it blow heat and tell me if the t stat is bad?

[stwkmoore]

Have you ever noticed sometimes when you get to close to the problem you can over look the obvious? I thought I would check the voltage to the t stat. I can not see any voltage reaching the t stat. From the transformer side going to the t stat I have 24 volts ac. The other side of the transformer still shows 0.01 volts ac. I starting to think I have a broken or cut wire from the heater to the t stat. I should see 24 v ac at the t stat, correct?

[Robert]

Hi,

Transformer Primary-Line side should have 240vac across the two spade terminals.

Secondary-Load side should have 24 to 28vac across the two spade terminals.

T-Stat set to OFF should read 24 to 28vac across RH/Red and W/White.

Removing red wire and white wire from t-stat and connecting together bypasses t-stat for heat mode.

IF problem still exists, t-stat is not the problem.

For more detailed step by step troubleshooting through email, go here:


http://www.mobilehomerepair.com/Order4b.html



Thanks,
Robert