http://dhclimatecontrol.com/hp.htm
I have a thread up in IR and discovered some folks don’t understand the refrigerant flow in a HP I am of the opinion that if one is to inspect a system even if its just operating it you should at least understand the basic principle of operation.
The above link indicates the flow of a heat pump it just shows basic items no extras. No dryer/filters no accumlators but it does indicate the state of the refrigerant as to liquid or vapor
Any questions ask away
thanks red hat that’s a good start…
Nice link Charley.
I hope some study it and ask some questions more should be like Juan he does not know when to stop asking questions;-)
Whats a heat pump??:mrgreen::mrgreen:
Up here in the fridged North we never see a AC unit running in reverse.
Added this part for yous guys… 
here’s the bells & whistles
http://www.hvacredu.net/heat_pump_animation.html
stat and defrost functions work
still lookin’ for the muffler, DA ;~))
I understand the flow and the workings and really appreciate the animated graphics.
My inspection yesterday was very cold because the heat pump would not come on and there was no ancillary heat source.
My question is: Using the thermostat switched to fan only wouldn’t that at least make the fan come on?
I found two thermostats and only one heat pump unit, neither would make the fan come on…
You have a zoned system.
Are are a number of things that will keep it from coming on.
You need an HVAC guy…
I called an HVAC guy I work with today and left a message on his phone. Apparently he is taking today off. (not a good way to start a new year;-))
The terminology of a “zoned system” sounds familiar, and hopefully I’ll be able to go with my HVAC buddy to check it out.
I took the day off (and I didn’t even have a beer last night!)
A zoned system is 2 t-stats, one unit.
If so much as a damper actuator does not fully open, it will not work.
Don’t wast your time trying to figure this type of unit out.
Even the HVAC guy may not get it right…
I called my customer today and he has an electrician/hvac and plumber coming Friday, and invited me to the party. So hopefully I can get better educated on this system.
How long did you wait, after turning on unit ? Just asking ! Just saw post, so all of this might already been answered.
Unit would not respond to the thermostats.
Just saw this. Thanks for answering them when you can. 
The main reason I asked was that on our service calls (other job) , when unit was off from someone going on a trip and returning, and informing that unit will not respond. Inform them that it can be from 10-30 minutes for it to crank up. Also this happens to the newer refrigerators, and other appliances. Computer board parts etc. need to warm up ! JUST SAYING…
Hi Jim,
Happens that I am familiar with heat pumps as I have one and have inspected quite a few in depth. I do know quite a bit about HVAC.
I would imagine it was an Air based system and not Water like mine though.
Yes, any one stat on the zoned system should have turned the blower on regardless if the Heat Pump/AC was working or not and the appropriate damper for that zone or both dampers should have opened.
With the house being vacant, and I do believe it was, could they have possibly turned the power off to the unit? I would imagine you checked the breaker.
Anxious to hear what the outcome of your meeting was.
Hey Michel,
The HVAC guy fixed an issue with one of the thermostats, and said a _____ part needed to be ordered. The customer couldn’t remember the name of the part, but no place had it in stock.
We are waiting for this part to come in and hopefully find out more.
Appreciate your input and concern…I’ll keep you informed…
Hey James,
Sorry, over looked you. That’s good information to know. That’s good enough information you should charge for it. Oh wait…you do…
This is an ongoing ordeal. I’m anxious to find out if this 1987 unit is going to fire up.
Any Time !