outside unit won't turn on (miller heat pump)
Hi all. I have a 10-year-old Miller by Nordyne 3.5ton heat pump with electric auxilary heat. The outside unit will not turn on.
I keep the thermostat set at 68. It has a swing of 3 so the temp drops to 65 (because the outside unit isn't doing anything) and the aux heat comes on just to keep the temp at 65, costing us a ton of money.
On the outside unit, if I push in the contactor by hand, the outside compressor and fan WILL turn on, so I don't think it's something as simple as a breaker.
I have verified that the Y terminal on the outside unit is getting 24V when it's supposed to be on, so I think the thermostat is OK. Also, if I just jump Y to Rh to force 24V on Y, bypassing the t-stat, nothing happens on the outside unit.
I turned the unit to cooling mode and dropped the thermostat to 35 degrees--the outside unit still did not come on.
I am seeing about 5V at the contactor coil...??? Maybe I'm not measuring that right.
I have a Rite-temp digital t-stat model 8050C (OK for heat pumps) that I installed several months ago. When I installed it, I verified that it cooled and heated. I used it most of the summer and it controlled the A/C well and controlled the heat well as we entered fall.
Anyway, I had a pro come out and look at it.
He said my thermostat was junk and not meant for heat pumps and wanted to sell me a non-programmable unit for $249. I explained that while my Rite-temp t-stat may indeed be a piece of junk, and I didn't think it was the problem, explaining what I wrote above.
Then he said he'd replace my contactor for $185 (it's a 621661 that retails for will under $20 as far as I can tell) but would not guarantee that the contactor OR the new t-stat would fix anything.
The tech said the outside defrost board was good but I don't know how he came to that conclusion.
For $75, his final diagnosis was that since I did not connect E to anything on the t-stat, and since I jumped W to Y, I did it wrong and that was the reason nothing was working.
When I installed the t-stat I followed the installation instructions carefully. I even double-checked things online, like why am I being told to jump things together and not connect E to anything. As I understand it, this is OK because E is for emergency heat, which is just the aux heat without the outside unit working, and the t-stat can do the same thing by turning on W2 and turning off Y. I even tried to explain this to him but he thought I was full of you-know-what.
Sorry for my little rant there, I just wanted to drive home the point that I don't think the t-stat is bad, and that I've consulted a pro, and still don't have a running outside unit.
Thanks in advance.