We have a 4 ton Carrier gas pack for our 1996 sq ft house. A 2 zone system was installed when the unit was installed in 2015. It has 2 thermostats and automatic dampers. We have only had great results. We are selling the home and the buyer's home inspector felt it was not working correctly because both thermostats control the unit (duh!). They are concerned the dampers are not working correctly. My question is if one zone is calling air, will some air flow still come out of the vents of the zone that is not calling air? We do not have a problem with temperature control and feel it is working well. I know that our unit is more than is needed for our ranch style home. I am pretty sure there is a bypass damper as well. Thoughts?
HVAC automatic damper in zoned system
hvac
Related Solutions
Some newer compressors have a built-in delay to protect them from damage. You should check the number of recommended cycles per hour in the manual to find out if this is an issue for your unit.
Damage could be caused by overheating over time, or a flooded start - depending on the design of the unit.
You should check the wiring in the furnace. There are no standards for thermostat wire colors, so you can't always trust the color of the wires. Seeing how the wires connect to the furnace, is a sure fire way to figure out what's what.
The O (cool mode) and B (heat mode) terminals are usually used for a reversing valve, in heat pump systems. I'm not familiar with oil systems, so I can't say for sure what they would be used for.
Some thermostats have separate O and B terminals, like this.
Others have an O/B terminal, and use a jumper to select which should be used.
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Best Answer
1 It sounds like it was installed according to standard engineering practices.
2 This type of installation is usual and customary practice by today's standards.
3 Sounds like the home inspector is out of his depth.
4 Have the original installed write a letter to the above effect. That should do it.
1 These type of dampers are fairly tight. They are gasketed. You should see very little air movement in the area not calling.