I’ve been using my Nest 3rd generation thermostat for several years now. When I moved to my current house, I had it professionally installed. This is my first summer in this house.
Last week, during a particularly hot day, the air conditioning ran for hours before it shut off. When I checked the thermostat, it displayed a “delayed” message with a countdown. Today, with similar weather, the same thing has happened three times. I’ve read on other forums that connecting a C wire might help, but I already have one connected.
What could be causing this issue, and how can I stop the thermostat from “delaying”?
The delay message might be due to incorrect wiring or power fluctuations. If the wiring isn’t properly connected at the furnace, the thermostat could have trouble maintaining a stable connection.
Brendan said:
The delay message might be due to incorrect wiring or power fluctuations. If the wiring isn’t properly connected at the furnace, the thermostat could have trouble maintaining a stable connection.
No, that wasn’t it. It was definitely a voltage issue. Turns out the thermostat wiring wasn’t done right at the furnace before I bought the house. Once my HVAC company fixed it, it has been fine.
I’m facing the same issue. My A/C struggles to keep the house cool when it’s really hot outside, and the thermostat keeps saying delayed. I think it’s a way to protect the system from overworking.
Maurice said:
I’m facing the same issue. My A/C struggles to keep the house cool when it’s really hot outside, and the thermostat keeps saying delayed. I think it’s a way to protect the system from overworking.
Yeah, I’ve had this happen too during a heatwave. I think it’s just the system trying to prevent damage. I ended up using ice blocks in front of fans and spending time in the basement to stay cool.
Maurice said:
I’m facing the same issue. My A/C struggles to keep the house cool when it’s really hot outside, and the thermostat keeps saying delayed. I think it’s a way to protect the system from overworking.
It might also be detecting an issue with cooling. For example, if a condensate drain float switch is activated, the thermostat may notice that the cooling line isn’t energized. Nest thermostats monitor voltages closely, so something like a low refrigerant charge could cause it to run inefficiently and trigger these delays.
A delay message usually means there’s a power interruption or an issue like a clogged condensate drain. Cleaning the pipes often fixes it. It could also be a refrigerant issue.
Russell said:
A delay message usually means there’s a power interruption or an issue like a clogged condensate drain. Cleaning the pipes often fixes it. It could also be a refrigerant issue.
Not always true. I have two thermostats, and one shows delayed while the other is running the A/C.
Russell said:
A delay message usually means there’s a power interruption or an issue like a clogged condensate drain. Cleaning the pipes often fixes it. It could also be a refrigerant issue.
This solved my issue. My upstairs unit kept showing delayed, and it turned out a clogged condensate drain was causing the problem.
Russell said:
A delay message usually means there’s a power interruption or an issue like a clogged condensate drain. Cleaning the pipes often fixes it. It could also be a refrigerant issue.
Good to know about the condensate drain. I’ll check that since a tech recently said my refrigerant levels were fine.
Russell said:
A delay message usually means there’s a power interruption or an issue like a clogged condensate drain. Cleaning the pipes often fixes it. It could also be a refrigerant issue.
I cleaned the condensate line, but it didn’t help. The delay message is back. What else should I check?
Russell said: @Hugo
Check your thermostat’s power levels. Google has a guide for this. If everything looks fine, it might be time to call a technician.
I’ve been monitoring the voltages, and they all seem fine. Thanks for the suggestion though.
Sometimes the delay happens because the thermostat detects inconsistent power from the A/C unit. This can be due to loose wiring or a faulty connection.
Brendan said:
Sometimes the delay happens because the thermostat detects inconsistent power from the A/C unit. This can be due to loose wiring or a faulty connection.
In some cases, the delay issue might be caused by background apps draining the thermostat’s battery. Try closing all open instances of the Nest app on your devices.
Brendan said:
In some cases, the delay issue might be caused by background apps draining the thermostat’s battery. Try closing all open instances of the Nest app on your devices.
I never got a definitive fix. Cleaning the drain helped a bit, but I still get delays occasionally. I’ve noticed that completely closing the Nest app on all devices seems to help. It’s like having the app open drains the thermostat battery, causing delays.
