My NTI boiler works during the day but not at night. The central heat function cycles through prepurge sometimes starts to run then goes back to prepurge. During the day it stays on heat until temps are reached. It switches to DHW pretty easily but only after the central heating temps are reached. My heating guy says it needs a new induction motor but if it's mechanical why would it only not work at night? Because it's not working at night it has to runn most of the day to warm the house. Any ideas?
Natural gas? Gas pressure drops at night in your area maybe?
It’s a union boiler: it’s against its contract to work after hours.
give us more info on what NTI boiler it is, and any other symptoms. Pics of the system as well if you can
If you're in Durango, CO, your night temps have been in the teens, and last night was down to single digits. @Jamie Hall may have the right idea. Are you on a ranch with a propane tank? If so you might have this problem:
