Navien NCB-180 fixes

mattvan123

So I bought a house a couple years ago in Mass. A navien NCB-180 was already installed in the basement. The living area includes two floors (not counting the unheated basement). The two floors have separate zones, but we hardly even heat the second floor when the first floor is warm enough (the second floor is bedrooms and we like it cooler at night).

There are three bathrooms, but rarely would more than two be used at once (so just say two may be used in the morning).

I've had a few issues. First, the device short cycles in space heat mode, and I've seem to have finally figured out that the baseboards actually use very little heat, so the return water temp is close to the output (maybe 8degrees). Sometimes I get an E012 flame loss error after short cycling, and only when space heating is running. I'm wondering if there is a solution other than expanding the baseboards because the baseboards we have heat the place enough. Maybe the Navien wasn't the proper choice, but that's what we bought the house with.

Second, the DHW seems find but there are small temp fluctuations during use. I'm trying to figure out if that is normal, or if any adjustment might help.

Jamie Hall

It may be significantly oversized. What is the heat loss of the building? There's no point in putting in more baseboard, if what you have heats the building properly. You'd just be turning the whole thing off with the thermostats, which wouldn't help much, if you had more baseboard...