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CarZin
12-23-2008, 12:05 AM
I had a Trane XL14c duel fuel unit and Honeywell HZ432 installed this past summer.

Tonight I noticed that the house was cold. Set point was at 68, yet the house was 63. Something not right. The air coming out of the vents was cold. The outside temp was under 30, and the zone controller was supposed to kick in gas heating from the heat pump after temp dipped below 35. I hit the 'emergency heat' button, waited about 15 minutes, yet the gas didnt come on.

I have a 2 zone system, and put both in emergency heat. No difference.

I went under the house, and saw the duct temp was in the 60s. I cant tell you for sure if the emergency light on the zone controller was on or not. But I clicked to 'config mode', then went back to operation mode, and then just like that, the gas furnace cut on for the first time.

Questions:
1) Any idea why this happened? This is the second time this has happened. I called the installer when it happened previously, and he promised to come out but did not. I actually thought the first time was a stat autoprogram screw-up, so I didnt call him back to find out why he didnt come by.
2) I notice that while the house is warming, it is periodically purging. The stat has been calling for 70, and its been trying to work the house up to 70, but it seems to purge fairly often. The stat should have been calling for heat the entire time, so its not cycling on or off. Is this the way a purge cycle is supposed to work?
3) I noticed in the config mode, that the gas heat was set to a 1 stage. I know its a 2 stage. I changed to 2 stage. Any problem with this?

I'll be calling him after the holidays as I have a work around, but would appreciate some opinions.

Sorry if this thread is a little jumbled. Doing my best to recall what actually happened.

lbf
12-23-2008, 12:30 AM
Be careful changing your settings in the config mode, you may change something you don't want to.
It sounds to me like you're shutting the system off and then back on and that's what's making the furnace come on. Your furnace may be going into a shutdown mode, you need to get your installer back out to get it checked out.

beenthere
12-23-2008, 06:09 AM
Does your zone system have a bypass?
It may have been tripping the furnaces high limit. And locking out after X number of high limit trips.
And you are just thinking these are purge cycles.

It doesn't purge in the middle of a heat or cooling call.

CarZin
12-23-2008, 02:55 PM
My unit has a modulating by-pass. I dont think I would be tripping the high heat limit. I have been watching the duct temperature, and it doesnt get too hot. Looks like I'll need to call him out and have him figure it out.

beenthere
12-23-2008, 05:27 PM
What do you call too hot.

The panel may jave the LAT set too low.
Or, it could still be tripping the furnaces high limit.

Make sure your contractor checks both.