When you say cold at night and warmer during the day what sort of temp readings are you getting?

At night it might be between 62 and 64 and during the day it varies but perhaps at times, 70. When we run the fireplace, it might get 75.

I can't really change the way we heat but I can cover the orchids, move them or just wait for the occasional second spring bloom.

Either way, I can't really enjoy them in the back bedroom.

Sometimes I blamed bud blast on humidity. I found that misting the air over the buds (not misting the buds directly) and letting it drift down on them helped. If not, I cut the flower spike to just above the highst bud and waited for secondary blooms which usually came after the heat was turned off.

Actually, i'm surprised that you have winter blooms. If you have them on an annual bloom cycle, they should initiate a new spike in late Autumn or winter and then bloom approx. 110 days later. This comment of course only relates to the pink or white standard hybrids.

In the past there have been comments about Gas fumes....?

I appreciate your replies. I will have to look up gas fumes too. I'll try the mister but I think I'm going to try a cloche too.

I do cut back the spikes after the first bloom and usually get to enjoy the second, small, round of blooms.
I keep them outside all summer and might get another bloom then too.

As far as bloom time, can I control that?
All three are purple or white hybrids. Nothing special but very healthy and pretty.