My home has a 5 ton Carrier heat pump (40YR060300) that was installed in 1991. I just had it serviced and the tech made several statements that I'd like some advice on...
1. Leaving the Fan On will actually help my units efficiency by maintaining a more constant temperature mixture. I have three rooms with 25 ft vaulted ceilings (4000 heated sqft)
2. Install a "two stage heat/one stage cooling" Digital Thermostat. I purchased a Honeywell RTH8500D. I'm a EE and very versed in wiring and I wired it in myself. I'm sure the wires are connected per the instructions.
The thermostat is selected for "Multistage Heat Pump."
Question: I'm not sure I have selected the correct System. My lights dim periodically (I haven't timed it but about every 10 minutes) as though the strip heat or compressor is constantly cycling on, even when the thermostat shows "Heat On" and not "Aux Heat On". As I was writing this, the lights dimmed and the thermostat cycled from "Aux Heat On" to "Heat On". Now it appears the compressor is not running (freon pipe never gets hot.)
[Edited by keith welchel on 02-13-2005 at 09:46 AM]
Call your tech back and have them install a real t-stat, not that Home Depot crap.
Is this the one?
No, that's not it...
What's a real one...
Are all Lowes/Home Depot Digital thermostats... not real...
[Edited by keith welchel on 02-13-2005 at 09:49 AM]
They sell cheap Homeowner grade t-stat's at Home depot. The one's you buy fro a contractor are better quality and have more features. Plus you will get a warranty on one installed by a contractor.
You get what you pay for.
I understand... but saving money isn't the issue... nor is debating real thermostats...
I'm following the techs suggestion... it's installed and I'm not going to call them yet...
I'd really like some help on the problem at hand...
You may have to change your cph
Or you may have miss wired it.
Check the install instructions, and you see where it mentions some system changes may have to be made.
To say much more then we have, would be step by step instructions to a DIYer.
Since you are an electrical Engineer (I assume EE is just that), you could probably do the math and figure that running the fan constantly costs more, not less so unless somehow the heat from the motor costs less than the HSPF of the unit itself, I suspect you have received a less than correct information. It may, and I cant comment on your system, be a comfort issue but it is not an efficiency issue.
The thermostats at HD or L are defeatured versions designed to look like the ones you can have installed by the contractor but at a price that appears to be competetive. Technicaly they work most of the time by switching on and off equipment but thats about it. If you are looking for technical support for that thermostat call HD or the 800 number on the box.
I understand for you the cost is not the issue but you have to admit, a few dollars saved up front have ultimately cost you more in unnescessary resistance heat operation and agravation.
well... I installed the original thermostat and still no compressor heating... time for a service callback...
Is anything running outside?
yes... the outside appears to be running normally... the Fan is running and it sounds normal...
on Friday when the tech was servicing my unit he thought the unit had been overcharged from a previous service (another company). he wasn't totally sure about the over charging and said that I need to have it checked again when the temp is over 70degF.
Doesn't sound stat related, compressor isn't starting for whatever reason. At 14 years old, could be getting towards the end of its life. Hard start kit or super boost could give it a little more life.
As a service technician for a large equipment dealer I would say,
The compressor is not working and it is probably going off on internal overload then cools down about every ten minutes and tries to restart again this is why the lights are getting dim. Turn the whole thing off for an hour then fire it back up if it still doesn't come on then you will need to have the compressor checked sounds lke it is either hard starting or already dead.