Mikerf12
New Member
Earlier this year I had a Navien NCB-180 Combi Unit Installed to replace a conventional oil fired boiler. The house is approximately 1500 Square Feet with 1000 Square feet on the first floor and 500 square feet on the second floor. The upstairs zone never runs as the heat from the living room rises and keeps the upper floor which open to the living room heated. For the first heating season and 1/2 of this season the boiler was run at fixed water supply temperature of 167 degrees with a Lux Geo programmable thermostat with a daytime and nighttime setback.
The boiler was essentially running almost the entire time when we were in the home and the setback was off. We also noticed it would take a very long time for the temperature to return from the setback temperature in the morning.
About a week a go I added the Outdoor Reset Module to the system. I adjusted the temperature setbacks on the thermostat to a 2 degree difference at night and when we are at work. The house seems to be heating well, however the the system seems to be running for a very long time. It seems to take at least two hours to climb the two degrees from the night set back to the morning setback.
In looking at the run time reports the thermostat is providing it looks like it is running any where from 10 - 12 hours per day in the three days it has been installed and running on the schedule. On the weekends the temperature is set to a fixed temperature and it runs much longer 18-20 hours. It has has been warm here in Connecticut the past few days.
Below you will find the schedule I have set in the thermostat. The only difference before the outdoor reset was installed was the 66 degress was set to 62.
Monday - Friday
11PM - 5 AM - 66 degrees
5AM - 8AM - 68 Degress - The house doesn't really hit the 68 in this period, as space heating is limited due to two showers and needing DHW, this may need to be removed or adjusted to get warmer earlier.
8AM - 4PM - 66 Degrees
4PM - 11 PM - 68 Degrees
Saturday - Sunday
5AM - 11PM - 68 Degrees
11PM - 5AM - 66 Degress
The question really becomes what is the average run-time a system like this should be running for? It seems like the system is running for quite a while and I don't know if the settings need to be adjusted or outdoor reset curve adjusted.
My plan is to run the system for one month to benchmark the performance, but have been reading a lot of good posts here and figured I would write up a post.
Thanks for the help in advance.
The boiler was essentially running almost the entire time when we were in the home and the setback was off. We also noticed it would take a very long time for the temperature to return from the setback temperature in the morning.
About a week a go I added the Outdoor Reset Module to the system. I adjusted the temperature setbacks on the thermostat to a 2 degree difference at night and when we are at work. The house seems to be heating well, however the the system seems to be running for a very long time. It seems to take at least two hours to climb the two degrees from the night set back to the morning setback.
In looking at the run time reports the thermostat is providing it looks like it is running any where from 10 - 12 hours per day in the three days it has been installed and running on the schedule. On the weekends the temperature is set to a fixed temperature and it runs much longer 18-20 hours. It has has been warm here in Connecticut the past few days.
Below you will find the schedule I have set in the thermostat. The only difference before the outdoor reset was installed was the 66 degress was set to 62.
Monday - Friday
11PM - 5 AM - 66 degrees
5AM - 8AM - 68 Degress - The house doesn't really hit the 68 in this period, as space heating is limited due to two showers and needing DHW, this may need to be removed or adjusted to get warmer earlier.
8AM - 4PM - 66 Degrees
4PM - 11 PM - 68 Degrees
Saturday - Sunday
5AM - 11PM - 68 Degrees
11PM - 5AM - 66 Degress
The question really becomes what is the average run-time a system like this should be running for? It seems like the system is running for quite a while and I don't know if the settings need to be adjusted or outdoor reset curve adjusted.
My plan is to run the system for one month to benchmark the performance, but have been reading a lot of good posts here and figured I would write up a post.
Thanks for the help in advance.