I have an Source1 HVAC control which is failing. It works. turns on the heat, but shuts off prematurely. Does anyone know if it is possible to fix it, or is that too complicated to try fixing by replacing the heat damaged resistors and diodes? see front at
BTW, this image was scanned with a HP desk scanner
inch farther out? I was thinking of removing the glass cover and hope the head don't touch the board!
It may be going out on safety. You need an experienced tech check out the system to see if the board is at fault, or if you have another problem that's shutting down the system.
Hi!
That looks similar to a controller I've seen in a Comfortmaker furnace. The controller in that application was known as "The General
90" and was also made in Mexico. Although it had fewer components on it, the connectors were very similar and in about the same positions.It's mentioned on that particular controller that no service is possible, so don't expect any help from the manufacturer. They'll probably try to sell you another one.
What I'd look at are any and all capacitors, to see if any have failed. If the module is mounted on the furnace blower, it should have very good cooling, so heat related failures are unlikely as long as the blower is running. :-) But if it's not in the path of some airflow, or if it's near a burner, the capacitors are a likely candidate for problems. They won't stand the heat, as the electrolyte dries up and makes the capacitor fail. If you do not have a capacitor checker, look for bulged tops or brown flaky residue on the capacitor tops.
If that doesn't turn anything up, the glue that seems to be all over that board should be investigated. Some of it may have turned conductive over time. This will produce strange results.
Finally, examine the relays. See if you can pop them open without undue violence. You may find burned contacts that don't do what they are supposed to do reliably. Fixing this may be a little difficult-- usually some gentle abrasion of the contacts to clean the burnt material away will work, but eventually you will need a new relay as the damage will eventually return. If the manufacturer of the relays is still making them, and they are not a custom part, you may be able to get them.
William
Hi!
Probably not easily or at all. I believe you'd have to change the scanner's optics considerably to pull this off. Do you have a digital camera?
If you do, it should do an acceptable job of photographing the board and its components. Any macro mode that is available can be used for close ups.
William
Flatbed scanner for circuit board? Neat! I didn't see any really bad solder connections. A friend of mine is a computer repairman. I've done a bunch of circuit board solder, but that was decades ago. I'm sure I've still got the touch. You may have a computer guy near you who can look it over.
At the moment, I'll agree with my esteemed colleague, Steve. And suggest you call a furnace tech. Sounds like the board isn't the problem.
What brand of furnace is that on? I assume it is a gas unit. Most furnace boards have an LED status indicator that blinks out codes to aid in troubleshooting. Does yours? Larry
It is on a York gas furnace Actually, it blinks 4 times. message in manual =3D This indicates that a primary or auxiliary limit switch has opened its normally closed contacts. This condition maybe caused by : dirty filter, improperly sized duct system, incorrect blower speed setting, incorrect firing rate, or faulty blower motor. The filter seems clean. I removed it just to be sure. What would cause an incorrect firing rate? What exactly is a limit switch? Is it that switch (which I shorted for diagnostics) which detects the cover plate on?
However, when I replace it with a Johnson Control G951ADB-1402, the furnace worked just fine.
BTW, I found one place
Lets see. The board is telling you there is something wrong. You try a different board and now you get heat. But that doesn't mean the furnace is OK. Might mean you have a board that doesn't read the sensor in question. You may still have a dangerous condition.
A limit switch is a safety switch that shuts the burners down when the furnace gets hotter than it normally should. A primary limit switch is normally locateed near the heat exchangers. Some furnaces (downflow models) usually have another limit called an auxilary limit. It sounds like you have an air flow problem and aren't flowing enough air thru to keep the heat exchangers down to a safe temp. Do you possible have an A/C coil mounted on the furnace that could be plugged up with dirt & lint over the years? This would restrict the air flow. It could be several other things. It's best if a tech checks it out.
Checking this out right now. I assumed that the limit switch was something that detected if the front panel was on. BTW, I have a 6K sq ft house with 4 HVAC units. The HVAC in question is rated for 3 tons. It also should heat the living room, kitchen, dining room and library, which are on the bottom floor of the house (heat rises up the staircases), and the kitchen and dinning room are on a concrete slab covered by stone tiles with two fireplaces. It is about 25F at night outside and the rooms get to be around 60 deg F. I was wondering if this is an undersized unit for this house.
Yes, the AC coil is mounted over the York furnace.
Remove the blow up doll from the return air register from your son's room.
Those AC coils are noted for clogging. Also nearly impossible for home owner to get at, to clean.
Does anyone know how to clean it out see a pic
Yes, looks pretty routine to me. A basic clean and check.
The problem was that I mounted the fan backwards.
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