Hello All, First my apologies for posting this question as a response to an existing thread. I just could not figure out how to start a new thread and no matter what I tried, I was going in circles. Anyhow, I hope this question is relevant to this thread and will appreciate any answers. First the facts: I had a 5 Ton Rheem heat pump installed in our home to replace an 18-year old Lennox heat pump (Model HP22-461-2P) of about 3 or 3.5 Ton capacity which ran its course of life. The Air Handler is installed in the Attic and the external unit is outside. I bought the unit brand new and had it installed by a licensed HVAC contractor. The model of Rheem Air Handler Installed inside the Attic is RHPL-HM6024JC. The model of Rheem Heat Pump (External unit) is RPRL-060JEC. They are purchased as a packaged unit from a Rheem wholesaler through the web and I confirmed through Rheem officials that the units are compatible with each other and the seller is licensed to sell them. These are installed by a local contractor with a Honeywell FocusPRO TH6000 series thermostat which he, the contractor supplied on his own as per the agreement we signed.. The heat pump is advertised as 2-stage. Now, the problem: From the time it is installed on January 26, 2012, the outside fan is not blowing. I asked the contractor about it, and he seemed not sure, but told me not to worry about it and that it will come on when necessary. Then I read a little bit about heat pumps and also recalled that in the case of the earlier heat pump, the outside blower was running much of the time. Toward the end of its life (i.e., just before the installation of the new unit, however, the outside unit had ice formed all over it, and the fan was still struggling to run. A few contractors who came to look at it to give an estimate said that the old unit pretty much ran its life and that it needed to be replaced. One of them said with so much ice outside the heat pump is doing nothing but wasting electricity and disconnected the outside unit from the socket and asked us to put the inside thermostat to emergency heat because that is how we were getting the heat anyhow. This was the condition at the time of the new installation. The new contractor of course, threw out the old outside unit as well as the in-the-attic air handler and and replaced them with the new Rheem units and installed the Honeywell thermostat FocusPRO TH6000. Since the installation, I kept observing the outside unit and found that it was never running. I contacted the contractor after a couple of days and he said we could test it by turning off the circuit breaker for the outside unit off and wait for 5 minutes and then turn it on to see if it would come. When we did that, the outside unit fan did come on, but within a minute or two after picking up speed, it shut itself off. The home is getting heated, but I am concerned that the unit is running as an electric heater rather than as a heat pump because the outside fan is not running at all. This seems extremely unusual. I wrote to the supplier and he says the problem is most likely caused by wrong installation or wrong wiring. When I asked the contractor about it, he adamantly maintains that there is Zero Wrong with his wiring, but he does not have an explanation as to why the outside fan is not blowing. I wrote to the supplier again, and he says that in the most unlikely event that something is wrong with any of their components, they will replace them under warranty if I get a written estimate and a confirmation of the problem. My guess is that the contractor made some error in the wiring, perhaps a simple one, but am not sure what it is. According to the Owner's manual I downloaded, the Rheem heat pump is with serial communicating technology and it consists of Indoor Air handler, Outdoor air conditioning condensing unit/heat pump, and a touchscreen thermostat. The touchscreen thermostat is not supplied along with the heat pump and air handler. I asked the supplier about communicating technology and he responded that they could supply it for about $400 extra. They confirmed that "The heat pump system is definitely equipped with Rheem's Comfort Control System Serial Communicating Technology. Looking at the specs document you can see that the heat pump is equipped with this technology. The air handler you bought RHPLHM6024JC is also Communicating. This system was designed as a matched Communicating system. In order to achieve the benefits of the Communicating system you will need a Rheem 500 series thermostat. The thermostat is not included in in what you purchased. To keep prices low we sell matched split systems and let customers choose their own thermostats." I would like to know: a) How we can diagnose the reasons for the outside fan not running b) Whether the outside fan is supposed to spin when the unit is on Heat and the temperature is cold outside. c) How we can fix it to ensure that the unit is functioning as a heat pump d) Whether it is advisable to consider purchasing the thermostat recommended by Rheem have it installed. Thank you for any info or guidance you can provide.

1. Not if you want to avoid problems down the road. 2. I think American Standard/Trane is one of the best. Get another quote or two. Did the American Standard guy explain the pitfalls of just replacing one unit (warranty, reliability, performance)? Having a 10 SEER air handler on a 13 SEER heat pump is not a good idea. You may even get less than 10 SEER.

American Standard makes Trane so they are pretty much the same. If the warranties are the same and they both have the same features, I would go with the least cost system.

I hadn't looked at the info for that thermostat until just now. Wow. That really is the next generation (web connectable, controls every equipment permutation, wireless sensors). Fair warning that I know enough to be dangerous, so take that into account when reading the rest of this. The link below shows the install manual. Pages 19-20 explain some of the backup heat options/settings (although not in as much detail regarding settings as the manuals for the Vision Pro series). I'd let the installer make any changes, but this may help you get a little better informed about the options- or it may just confuse things worse. The adaptive intelligent recovery (set 'on'), not having too big a setback due to the HP system, the backup heat differential setting, and the backup heat upstage timer setting look to be the key settings to minimize how much your backup heat gets used. As for the register air temperature, the important thing is the temperature differential between the room and the air coming out. For example, it was 32F outside at my house last night, my house was holding at 68F, and the air coming out of a register at the end of a branch of my HVAC was 81F. For my system, a 13F differential is OK (not great), but it's also right above the outdoor temperature where my heat pump is locked out and the gas furnace comes on. As the outdoor temperature rises into the upper 30's, the register air temperature rises to 88F or higher. You want to know what this temperature differential is, with just the HP running (no strips) to tell whether the HP is doing its job. Low temperature differential means the charge is off or something else is going on. I have a BBQ/oven temperature probe that's stuck in the register in my laundry room (when I'm not using it for BBQ). After my system lost most of its refrigerant 18 mo.s ago, I started watching to get an idea if it was happening again. It looks like you could add sensor(s) to your super-snazzy Honeywell and it could measure this and warn you all by itself. Here is a link that might be useful: Honeywell Prestige stat install manual