[Spridgets] Mini heater question

[lindalnhvt at nhvt.net]

Thanks for the previous suggestions from many of you.
I have a cable operated valve in the hose going from engine bay to heater.
It seemed to be stuck, but after freeing it, I have no heat coming from
the heater. Then I removed the valve and replaced it with a splice. The
hose is hot on either side of the splice and to the firewall. I don't see
anything under the dash that leaks or seems to be disconnected. Should I
suspect a bad heater core? Any other ideas?
Thanks.
Dick B. in  NH