Scott M wrote:

Sounds like your flaps are stuck open. The problem is the heaters are
letting all the heat out at night instead of holding it for when it's
wanted later.

One thing I've found again and again with E7 heaters is that only a very
few sad people (like me) can be bothered to work out how they work and
how best to work with them. The upshot is that "they" will crank both
controls to maximum and wonder why it's cold by 10am.

Just to add: this was a general observation and not a pop at the OP!

--
Scott

Where are we going and why am I in this handbasket?