Zone controls gone bad?

[andyvh1959]

Bought my 1973 vintage trilevel in 2002. Lennox HM30 furnace/hot water combined was the worst POS I have encountered. Finally replaced it in 2012 with a good Lenox furnace and separate gas hot water heater. Been good, except the last few years had issues with the furnace running like nuts even when I set the main thermostat at 68 F, to the point the bedroom end of the house is at 74 F. In fact it seems the thermostat in the lowest level has priority that it didn't have years past. I can adjust the lower level thermostat a few degrees up or down and it has big impact on the bedroom end of the house. I have the HVAC contractor coming Wednesday to check things out. I suspect the zone control dampers are the issue.

 

[gmcgeo]

i think you are right on track

 

[andyvh1959]

In this tri-level house I have three zone control dampers on the HVAC system. Zone 1 damper is the bedrooms end of the house. Zone 2 damper is the slab level den/office, dinning room and kitchen. There is a Zone 3 damper on the exhaust duct feeding into the chimney. This furnace has the intake and exhaust going out the back of the house. So the damper in the duct to the chimney is basically to limit chimney draw effect on the furnace (I assume), or to limit wind induced downdraft into the furnace.

I was at the Perfect Temp 6202 logic board/control panel in the basement when the furnace powered up. The logic board indicator light showed Zone 1 damper closed. Interesting because I have the thermostat for Zone 1 set at 69 degrees. The thermostat for Zone 2 is set at 65 degrees and the logic board showed Zone 2 damper as open. Hmmm. So I depowered the Zone 1 damper, and the spring opened it. I going to leave it that way for tonight to see how the house feels.

Interesting too, the Perfect Temp 6202 only has connection terminals for two dampers. But someone ran both the Zone 2 and Zone 3 dampers into the same power lugs on the logic board. So anytime Zone 2 damper is open, so is Zone 3. Not sure why the Zone 3 damper should ever be open. I also set the Zone 1 thermostat to 65 degrees and Zone 2 thermostat to 70, and the control panel showed no indicator light changes. I hope its not the Perfect Temp control panel.

 

[PoorUB]

I haven't worked on a Perfect Temp for years, but the dampers generally power close. If you remove power they should open, send power to them they should close. Pretty easy to trouble shoot. Keep in mind when a zone has a call for heat or cooling that zone damper is not powered.

Keep in mind you need to verify the thermostat for that zone is working. Just because it it is set to heat of cool doesn't mean any power is going to the control .

I am confused about the zone 3!

 

[gmcgeo]

In this tri-level house I have three zone control dampers on the HVAC system. Zone 1 damper is the bedrooms end of the house. Zone 2 damper is the slab level den/office, dinning room and kitchen. There is a Zone 3 damper on the exhaust duct feeding into the chimney. This furnace has the intake and exhaust going out the back of the house. So the damper in the duct to the chimney is basically to limit chimney draw effect on the furnace (I assume), or to limit wind induced downdraft into the furnace.

I was at the Perfect Temp 6202 logic board/control panel in the basement when the furnace powered up. The logic board indicator light showed Zone 1 damper closed. Interesting because I have the thermostat for Zone 1 set at 69 degrees. The thermostat for Zone 2 is set at 65 degrees and the logic board showed Zone 2 damper as open. Hmmm. So I depowered the Zone 1 damper, and the spring opened it. I going to leave it that way for tonight to see how the house feels.

Interesting too, the Perfect Temp 6202 only has connection terminals for two dampers. But someone ran both the Zone 2 and Zone 3 dampers into the same power lugs on the logic board. So anytime Zone 2 damper is open, so is Zone 3. Not sure why the Zone 3 damper should ever be open. I also set the Zone 1 thermostat to 65 degrees and Zone 2 thermostat to 70, and the control panel showed no indicator light changes. I hope its not the Perfect Temp control panel.

I would check a loose connection at the board for zone one. Other than that i have not heard to many problems with these boards.

The zone 3 issue sounds like its the way they wired it......

 

[andyvh1959]

Funny you say that. Last night I was checking the Zone 1 damper connections on the control board, and the hot side was not tight. That may explain why sometimes the heat throughout the house was more uniform, consistent. So I tightened those. But yet when I have the Zone 1 thermostat set for higher heat than Zone 2, the control board LED shows the Zone 1 damper energized, closed. I'd assume that when Zone 1 calls for heat the Zone 1 damper would be open. Each time I've checked the control board, Zone 1 LED for the damper is closed and Zone 2/3 are open, no matter the thermostat setting for Zone 1.

 

[gmcgeo]

yeah, something sounds off. has it always been an issue?

i know you said last few years, did a tech work on it in those years?

 

[andyvh1959]

The furnace was installed back in Nov 2010, ran fine for many years, still does in fact. Times when HVAC service guys came over they never said anything about the control board, and neither did I. But for at least the past two years in my laziness I just dealt with it by adjusting the thermostats for Zone 1 and Zone 2 until I found a tolerable medium. This year my wife asked I get a technician in to check it out. So that is scheduled, but then I also studied the PerfectTemp manual, schematics and zone dampers to find what I've reported just this week. The technician is coming over tomorrow morning, should be interesting to find the answers.

 

[gmcgeo]

Let us know what he says, i am interested to know

 

[fitter30]

Third zone need a hrv or erv instead of the damper for exhaust. Don't have a clue why anyone would want the house in a negative pressure.

 

[PoorUB]

Funny you say that. Last night I was checking the Zone 1 damper connections on the control board, and the hot side was not tight. That may explain why sometimes the heat throughout the house was more uniform, consistent. So I tightened those. But yet when I have the Zone 1 thermostat set for higher heat than Zone 2, the control board LED shows the Zone 1 damper energized, closed. I'd assume that when Zone 1 calls for heat the Zone 1 damper would be open. Each time I've checked the control board, Zone 1 LED for the damper is closed and Zone 2/3 are open, no matter the thermostat setting for Zone 1.

Have you checked to see if there is power between the W terminal and common terminal on the zone 1 connections at the board? If zone 1 never changes status no matter where the 'stat was set I would suspect 'stat or wiring, but it still could be the board.

 

[andyvh1959]

No have not done that. But when I reconnect the Zone 1 damper white wire to the terminal on the control panel, the damper motor actuates the damper closed, as indicated by the LED status light.

 

[Kliner78]

SO two dampers on one zone is perfectly all right. as long as there isn't two thermostats controling that zone, Also have you lokked to see if the duct supplying that room comes from that zone and maybe got attached to the main trunk prior to the damper? Some other things to check. Is the zone controller power wired into the air handler? nbecause if so it shouldn't be. It should have its own power source! If there isn't another transformer installed to power the zone board and the dampers and the tstats that could be a problem. First because the transformer is probably a 40 VA transformer and the board and additionla components are too much for it requiring the need for the addiytional transformer. I typically use a 75VA transformer. The secxond reason is that if you have it all hooked to one they tend to pick up interference through other surrounding devices giving you what we call ghost voltage and making the dampers not function properly.

 

[andyvh1959]

All good points. I have been in this house since Sept 2002, and never had any issues with the control panel or dampers for the zone controls. Back in 2010 the same HVAC company that installed the old furnace in 1995 also did the new furnace. So anything with the zones/dampers/power is as its been since 2010. Up until about two years ago is when I first noticed any issues.

HVAC tech was just here and he checked the control panel and zone dampers, confirmed everything is still good. He did mention the thermostat for Zone 2 is located in an area low in the house, only four feet off the slab level. Zone 2 controls the west half of the house from the slab level up to the dining room and kitchen. This is an open floorplan contemporary trilevel house with the dining room and kitchen at the same level as the bedrooms, but at opposite ends of the house.

Because the Zone 2 thermostat is so low in an area sensing the coldest part of the house it is constantly calling for heat and over-riding the demand for the rest of the house. The Zone 1 damper is closed most of the time then to direct heat to Zone 2. That correlates to what I've typically done to manually balance heating in the house; I set the zone 2 thermostat at about 64 F and zone 1 thermostat to 68 to 70 F to get the heat where I want it.

So today I relocated the zone 2 thermostat up into the main level so it better senses the desired temperature in the dining room/kitchen end of the house. So far the furnace is acting as I'd expect it should to the thermostat settings for the two zones. This house has a lot of whole brick inside and the better location options for the zone 2 thermostat means routing wiring up through the brick. Or, I route small diameter conduit up the brick face, colored to match the grout, to a level better suited to sense the temperature setting. Or,...find a remote temperature sensor that could send a bluetooth signal to a receiving thermostat. Hmm, the company I work for makes a bluetooth capable temperature sensor.