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Hi! Our AC/heat combo unit suddenly won’t heat or cool. We’ve managed to get it to do so a few times when we removed the cover and disconnected/reconnected a piece on the front panel but then that stopped too. Amy ideas where to troubleshoot?
Hi @tmr1975 , There are 6 models in the LRA08PZU1 series i.e. LRA08PZU110, -111, -112, -113, -114 &-116, but they all appear to have the same wiring diagram. Although looking at the parts list it appears that models -110 to -113 use the same main board and control (display) board and models -114 & -116 use the same boards but they are different boards to the the boards used by the other models. Here’s an image of the wiring diagram for the -110 model which may help.
(click on image to enlarge for better viewing) Looking at the diagram (as minimal as it is) it seems as though everything is controlled by the control (display) board controlling the main board. It appears as though relays are used to control the power to the compressor, the fan and the heating element. Can you hear if any of the relays “click” when trying to start the A/C? Is the compressor humming at all as if trying to start? If so it may be the start/run capacitor that is the problem You may have to open up the A/C and visually inspect the main board for any obvious problems and then start testing from there. The wiring diagram at least shows the connectors where the power comes into the board and also where all the peripheral components are connected to. Here’s a link to a supplier that shows the parts for a -110 model which may help as it shows where everything is. If it is determined that the problem is on the main board (part #37) and not the control board (part #8) I cannot find a schematic for the main board which would help to isolate it further but its part number is 5304483215 The same main board is used in models -110 to -113 but a different board part # 5304496429 is used in models -114 & -116. I can’t find a schematic for the control board either - part #5304482936 (model numbers -110 to -113) and part #5304496261 (models -114 & -116) All the suppliers linked were just to show what the cost of the part may be. There are other suppliers online that may suit you better. Just search online for the part number only to get results. Hopefully this is of some help.
If you can’t find a schematic of the board, then you may have to.do this next bit. Do it CAREFULLY!! You’ll have to remove the unit from the outer casing and set somewhere like a table where you can plug it in and test. When calling for n cooling what is running? Fan motor? Compressor? I believe you said compressor wasn’t running. Check and see is it getting power? Is the capacitor good? There should be a value on the side of the capacitor. Check and see if it is within 3% of that number. If not, replace it. Capacitors, relays, and contactors are a much more common failure point than a compressor.
Sadly your heat pump refrigerant has leaked out or your compressor has failed. Depending on its age you may need to replace the unit as the older units use ozone damaging fluorocarbons (Freon). If you have a portable unit you might be able to bring it into someone who can find the leak patch it and then refill it. Otherwise you’ll need to hire an HVAC tech to come out to fix your system.
