First thing is to replace the regular heater valve, which might not be
working.  Or, put a couple of drops of oil in the tube that connects the
shut off lever to the valve.  Just doing the latter made a big difference
in mine several years ago.  But after a couple of years, then, I did have
to replace the valve itself.  Next, as Thomas says below, a complete
overhaul of the under dash set up, but a lot more work.  I haven't had to
do that yet.  mcneely

On Tue, Jun 29, 2021 at 8:25 PM John Rodgers <jrodgers113@gmail.com> wrote:

> My front heater is putting out some heat all the time, even though
> everything is in the off position. At this point I am interested in just
> cutting off the water to the heater core. Anyone know how to do this? How
> to put in a shut off valve somewhere. Got a link to a how-to video maybe?
>
> Thanks
>