We have a model ATV034A110NRT WaterFurnace Premier in our floating home. I'm not sure when it was installed as it was here when we bought the house. It is very efficient and we've been happy with it. Winter before last the heat pump quit working while we were away and our electric bill tripled. A service guy came in and tested it. He said is was working fine, pressures were good, etc. Turned out the thermostat was bad upstairs in the living room. So then this summer the AC started acting up. Initially it was only on the hottest days. The compressor wouldn't start. I would go take the lower cover off and hit the side of the box with the logic board inside of it and the thing would start up and work fine. But it gradually got worse and I started leaving the covers off to keep things cooler inside of that box. That worked for a while, then it just wouldn't start no matter what I did. Fortunately that happened on the last hot day of the year, but now the cooler weather is coming along and I need to get it working for winter heating. I would like to fix it myself if possible. I'm not an HVAC guy, but I am pretty experienced at fixing stuff and was formerly an electronic technician specializing in digital equipment. On the other hand, I have only a multimeter now and unknown access to parts. The logic board inside of that box is part number 17P500A01 Rev. A. It has a bunch of relays on it and it seems likely that a relay has died. The board is pretty old looking, dirty and has no shiny metal on it at all. I would be willing to replace the board, but I can't find a replacement. Does anyone have one they'd like to sell me? Or any idea where I can buy one? Any other suggestions on more sophisticated troubleshooting than a board swap are welcome, too. Thanks, --Brian Godfrey
I have a 17P513-03 REV E if that will work could give you cost on it. Can you upload a pic of existing board?
I don't know if it would work or not. I'm not even sure how I would find that out. I tried contacting WaterFurnace and they are completely uninterested in anything other than selling me a new unit. (Hint to WaterFurnace and others: if you want repeat business you need to treat your customers right.) I am going to attempt to post a photo of my logic board here (wish me luck!) Cool, looks like it worked. Boy, I can sure see the board better this way than bending over and peering at it with a flashlight.
Hey, here's some news. See those two fuse holders at the top of the board? Well I checked the fuse in the one on the left a few weeks ago and it was fine. But I didn't even see the one on the right until I was looking at this photo. In real life it is hidden behind all those wires in a dark corner of the room. So I pulled out that fuse and it is blown. It is a 10A slow blow fuse. Given that there are two of them, I'm guessing that they might fuse the compressor motor. If so, then that seems like pretty bad news. I got some replacements today and I'll stick them in tomorrow morning when someone will be around to keep an eye on it all day.
Those fuses are NOT for the compressor. They fuse 230v accessories (DSH pump, Loop pump(s) and sometimes fan stages with a PSC blower). One of those components has blown the fuse. You will have to find out which and why. Do not condemn the control board yet (fix the fuse problem first). There has been several revisions for that obsolete board and some dip switch functions have changed. A newer board will have to be setup properly and might have different settings than existing depending on your configuration. Attached is a snip of the control boards typical layout in some versions. Your relays may be in a different order. You will have to trace wires or read the wiring schematic to determine their existing function.
Thank you for that scan! I'm not sure what a DSH pump is. My loop pump is a big external one like you would use for a well pump or for irrigation. I'm in a floating home and this pump pulls up river water and circulates it through the heat exchanger and drops it back into the river. It is controlled by a battery of really big relays which are not WaterFurnace equipment. Perhaps these relays are driven by the Loop Pump circuitry? I will have to figure that out. I'm not condemning the control board, but I remain suspicious of it because during the gradual failing stages a sharp rap on the side of the metal box that houses it would cause the heat pump to start working. And that control board has four 2o year old relays on it and relays get sticky when they get old. I think there is a schematic pasted onto the inside of the large lower door on my unit. I'll see if I can get a decent picture of that to study. (I really liked taking a picture of that board which I could then study in the comfort of my office. )
I finally found my missing multi-meter and started probing around. While following wires I found two wires (pink and blue) with blackened insulation. Isn't that interesting? They appeared to have been slow-cooked, not a sudden charring heat. According to the schematic, and confirmed by my eyes, they go to the DHW pump. According to note 9 on the schematic this pump is "only in models with hot water generation option". My furnace does appear to have that option - there are water circulating plumbing connections on the front of it. But those pipe connections are just plugged. This option has never been hooked up or used. So a question: will there be any side effect if I just disconnect that pump? I wouldn't think so, but is it possible that it has to be able to circulate water internally even thought it doesn't leave the furnace? I would just pull it off and see, but don't want to ruin anything else if I can help it. Thanks.
The pump SHOULD be disconnected if not piped in a circuit and filled with water. The water filled system lubricates the pump. If the DHW or DSH (DeSuperHeater) or HWG (Hot Water Generator) was never piped and filled with water than the pump is surely seized by now causing high current draw, overheated wires and blown fuse.
Thank you. That was my assumption, but since the house was warm last night and the furnace was off I figured I'd ask just to make sure there wasn't something I was missing. Yes, the pump must have seized. Frankly, it's amazing that there have been no problems until this summer. Or maybe this is just a red herring and I'll unplug it only to find that the thing still doesn't work.
