mobilehomerepair.com

We have a 1996 Doublewide that has a coleman evcon heater and central air. This has gone out and we had a service guy over and he stated that the control board is bad. We had used the heat since we moved in for about a week and then it quit. It is blowing fuses shortly after the blower kicks on.

He mentioned that water probably got in and created a short with the heater board. However, I have not seen any water damage, or stains and etc?

The cost is $300 (estimate) to replace the board. I do not yet want to get the board replaced in case it is not the board. Or if it is the board I want to see if we do have a water leak where water is coming out through the upper roof vent so I do not pay for this twice. My question is this something that I can replace myself. It really look easy just shut off the power, disconnect the old one and replace a few wires on it and power it back up.

If this is a do it yourself possibility where can I get the circuit board at?

Specs:

Coleman Evcon
Model: DGAT070BDD
Serial: 960443221

ELT-CB90-0045 circuit board

Hi,

I am moving this to the HVAC (heating,venting and AC) forums.
Please follow there.

Yanita

Hi,


Yes, it is DIY and we have the board if needed. If there is a short, they can be hard to find.


You should see any signs of water damage on or around the board.



I would locate another hvac tech with MH hvac experience for a second opinion.


Determining the reason for the board going bad needs to be found before replacing.


Did the fuse on the board blow ?



Thanks,
Robert

Yes, the tech has replaced the fuse. What happens is the heater will kick on then when the blower is going to come on (I believe) then it blows the fuse. It works great the first week we were there so I am not sure what happened since then?

What is the control board number that I need and how much is it? Thanks, Gary

Hi Gary,

Integrated Control Board # 7990-320P @ $176.40 + $8 shipping.

Install an inline fuse in the 24vac power side of low voltage circuit.

You should then use wiring diagram, start at transformer, disconnect components and power up one by one.


Follow circuit adding components back in until the fuse you installed blows.


When it does, the component and wire just added holds the short.


Look board over for any signs of damage. Also, trace the green wire from t-stat G to board G looking for bare spots touching metal or other wires.




Thanks,
Robert

Okay, I broke down and paid the $300 to have it done because I could not find the problem and didn't want it to end up blowing out the new board. The tech traced the short to the central air unit. The previous owner (was an idiot) took the live wire and had it shoved into the top of the ac unit. So when we tried to get air it basically shorted out the board via touching the fan blade.

The tech also noticed water marks on the cover of the heater board enclosure. He stated that he thought that the heater intake might be leaking. His suggestion was to disconnect the heater intake and put a piece of metal across the intake to seal it. He stated that this would not create a problem.

We have checked on rainy days and have never found a leak? Any ideas? We just do not want to have it go out again and end up paying $300 for it again.

What are you/he calling a heater intake ? Is it the Blend Air system maybe ?


Can you take a pic ?


Was the board actually bad ? IF the fuse kept blowing, that should have protected the board.


IF board was bad, nothing should have worked at all, not even long enough to blow the fuse.


Also, did he place 3A fuses inline before board and transformer ? Cheap and double insurance against loss of those components.



IF the heater vent is the blend air unit, you do not want to close it off.


This is reason for needing hvac tech with mobile home hvac experience.


Thanks,
Robert

Okay, the part that he mentioned to block off was a cylinder that is at the top of the heater? It is upon looking at the internet indeed the blend air system.

I was wondering if it was just the short from the ac unit that was blowing the fuses? We never had a problem with the heater before trying to use the central air?

I do not believe that he put in an inline fuse before the board. However he did reconnect the ac wire and we have turned off the breaker for the ac unit at the breaker box.

It was the motorized damper that he was mentioning to unplug and close off. Upon inspection of these pic from this website.

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

I assume that we should reconnect the blend air unit and hope for the best? Before the board was replaced it was just blowing fuses. Now it worked when it cycled though.

Hi,


The boards can have a short and be bad, I just wanted to be sure this had happened.


The fuse can blow repeatedly and it be due to an outside reason away from board.


Fix that (replace wire at condenser) and replace fuse and then see if all is ok.


Board may or may not be bad.


With the fuse on the board, a inline fuse in power wire on secondary side of transformer is all you really need to protect components.


Yes, do not disconnect the damper for the blend air system.



IF water is leaking in, find the source and repair that.


The blend air system is not needed for the hvac side, but is needed to rid attic cavity of heat, moisture and condensation which causes mildew and mold year round.


It also brings in fresh air to circulate with home air .




Thanks,
Robert

We have seen on the cover over the control board where it looks like water stains (per the tech) however, we have checked during multiple rain storms and have not seen any leakage? I am wondering if it because the previous owner did not shovel the roof around the vents and that lead to snow melting down?

My wife did mention that when the tech was here the first time it was blowing fuses then nothing. Hopefully, all is fixed and well because we love the home just do not want to have to fix it again later.

Thanks

Hi,


Just be sure no water or moisture is getting into furnace area anywhere.


Did the tech take the old board or did he leave it with you ?


Did it ever blow a fuse after he repaired the loose wire at outside condenser ?



Thanks,
Robert

He took the old board with him. I keep looking but I am not finding where their is moisture getting in? We haven't really run it much since it has been fixed but as of yet no blowing fuses.

We didn't notice the wire at the condenser until after the board was replaced. I believe it is under warranty to hopefully we don't have any problems.

Thanks,
Gary

Hi Gary,

Use silicon caulk to seal any openings where water may get in at top and side .


Hopefully all will be ok.



Take care and best wishes,
Robert