Heat Pump/Air Handler went out completely

[brian]

It was a little colder that morning and I think someone else may have kicked the temp up 2 degrees some time before it went out, but I can't be sure if the events coincided exactly. The exterior temp was probably in the low 40's that morning, which was colder than it had been for the 3 weeks it had been running ok. I had turned it up 2 degs about 1 hour before it was kicked up its last 2 degs. 68 to 70, then

70 to 72.

Thanks for all the tips and diagnostic speculating. Its all very helpful info.

Phil

[brian]

If this is a miswired thing, and the company that may have miswired it is coming out to check the system, and the 8 mo old heat pump they installed, then I'm worried if they will try to 'cover up' the miswiring and say it was something in the air handler instead.

I should probably take a pic of the wiring at the heat pump before they get out here today.

I just don't trust people anymore, its sad.

Phil

[brian]

If this is a miswired thing, and the company that may have miswired it is coming out to check the system, and the 8 mo old heat pump they installed, then I'm worried if they will try to 'cover up' the miswiring and say it was something in the air handler instead.

I should probably take a pic of the wiring at the heat pump before they get out here today.

I just don't trust people anymore, its sad.

Phil

[N8N]

Wow I just noticed a massive typo (well, not really, is it a braino?) in my original post, I meant "air handler" when I said "transformer." Hopefully you figured out what I was getting at.

nate

[brian]

If this is a miswired thing, and the company that may have miswired it is coming out to check the system, and the 8 mo old heat pump they installed, then I'm worried if they will try to 'cover up' the miswiring and say it was something in the air handler instead.

I should probably take a pic of the wiring at the heat pump before they get out here today.

I just don't trust people anymore, its sad.

Phil

[Don Young]

Transformers (and inductors) do not wear out and are among the most reliable of electrical/electronic components. They most often fail from overheating due to excessive current draw or from lightning or other high voltage surges, but they are not immune from inherent failure by themselves. As in many other component failures, it is often caused by a manufacturing defect such as poorly soldered connections, misplaced insulation, sharp edges puncturing the insulation, breakage of too tight wires, etc..

Don Young

[usethisone2007]

Guy came out for service call. Replaced the 5 amp fuse and said I want my check. I was happy it was running but really expected more of an analysis of what might have caused the fuse to blow. He didn't even wait for it to cycle through a full on-off-on heating cycle.

Next time I'll just replace the fuse myself...which I would have done if the panel for the air handler wasn't sort of sealed. Now I know better.

My concern is whether the fuse blew during a defrost cycle and that it might simply do it again.

Anyone know how often or what triggers a defrost cycle?

The weather here has been highs in the 50's and lows in the mid-30's. I'll feel happy after it stays running through a defrost cycle but have no idea when one would occur. He mentioned that they trigger during colder temps and I was thinking it might take a while until one got triggered.

thanks

-Phil

D> > Phil;

[Don Young]

Some units defrost on a regular timed basis and some have a more sophisticated system which tends to defrost only when needed. It is certainly possible but not real likely that the fuse failure will occur with each defrost cycle. It could have been due to a power surge, a fuse defect influenced by heat or vibration, corrosion of the fuse contacts, or probably lots of other things. A single fuse replacement without obvious cause is generally not reason for extensive troubleshooting. If it does it again fairly soon, then look for the cause.

Don Young