mrpaiken
New Member
I've had a Navien NCB-240/130H combi boiler now for two months. DHW is fine. Two heating zones each with its own circulator pump. The house is only 1,300 square feet.
Zone 2 is fine, but the other, Zone 1, is set for 69 and can't maintain temps more than 65 when the outside temp is below 50. Granted this room has two sliding doors that are old and leaky despite sealing and insulating cracks as much as possible. Regardless the old oil burner kept that room warm except when it would be extremely cold below 20. This morning it was 21 outside and 62 inside that room
The heating water set temp on the navien is maxed out at 180. When I keep an eye on the Navien control panel I can see that the temp mostly hangs out in the 160's but often goes as low as 139 and the unit will sometimes even show itself idle, but with the zone calling for heat and its circulator pump running. Attached pic shows the temp at 140, and the display green, meaning the unit is idle. It dropped a second after the pic to 139 before finally cycling up.
Eventually it will cycle on and slowly go up to high 170's but then cycle down and go down to 150-160 (or lower as I said) before cycling back up. I even mounted an iPhone on a tripod for the better part of a day to shoot a time-lapse vid, and I could see that even though the zone was constantly calling for heat, the temp hung out around 150-160 (occasionally down to 140) rather than 180. The Navien is running pretty much 24/7 and not able to maintain a 69 heat setting for that zone even in moderate outside temps in the 50s. Hardly efficient, let alone "high-efficiency!"
Of the two dip switch panels, the 6-switch unit had (only) number 5 up. My installer suggested switching that down to see if it makes a difference. I have and we'll see if it makes a difference overnight. I've looked online and in my Installation & Operation Manual and can't find any defined function for switches 3-6 so I'm not sure what that switch does or if 3-6 even do anything at all!
I'd love any advice or opinions anyone could offer. Thanks in advance!
Zone 2 is fine, but the other, Zone 1, is set for 69 and can't maintain temps more than 65 when the outside temp is below 50. Granted this room has two sliding doors that are old and leaky despite sealing and insulating cracks as much as possible. Regardless the old oil burner kept that room warm except when it would be extremely cold below 20. This morning it was 21 outside and 62 inside that room
The heating water set temp on the navien is maxed out at 180. When I keep an eye on the Navien control panel I can see that the temp mostly hangs out in the 160's but often goes as low as 139 and the unit will sometimes even show itself idle, but with the zone calling for heat and its circulator pump running. Attached pic shows the temp at 140, and the display green, meaning the unit is idle. It dropped a second after the pic to 139 before finally cycling up.
Eventually it will cycle on and slowly go up to high 170's but then cycle down and go down to 150-160 (or lower as I said) before cycling back up. I even mounted an iPhone on a tripod for the better part of a day to shoot a time-lapse vid, and I could see that even though the zone was constantly calling for heat, the temp hung out around 150-160 (occasionally down to 140) rather than 180. The Navien is running pretty much 24/7 and not able to maintain a 69 heat setting for that zone even in moderate outside temps in the 50s. Hardly efficient, let alone "high-efficiency!"
Of the two dip switch panels, the 6-switch unit had (only) number 5 up. My installer suggested switching that down to see if it makes a difference. I have and we'll see if it makes a difference overnight. I've looked online and in my Installation & Operation Manual and can't find any defined function for switches 3-6 so I'm not sure what that switch does or if 3-6 even do anything at all!
I'd love any advice or opinions anyone could offer. Thanks in advance!
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