On Mar 11, 9:45*am, gpsman wrote:
On Mar 10, 10:39*pm, "
wrote:

There is a small access door at the end of the tub but I have never opened the access door to see how much of the plumbing is accessible.

You wait right there, someone from Usenet will be right over to open
that door for you.
*-----

- gpsman

There are some serious issues involved, even if it is possible.
He might want to start with how the heater is going to be powered?
Usually a tub like that has a circuit for powering the pump. That's
probably on a 15 amp breaker. A heater would have to be fairly
substantial to be capable of heating a tub full of water. If the goal
is just to maintain it, less power will be required, but I'd think it
still would need something in the range of at least the typical
electric kettle. And those are 1200-1500w range, meaning
for this to work, he's probably going to need a second circuit.
That alone may be a show stopper, depending on where it's
located.

Then there are the various safety related issues, overtemp
protection for the heater, etc. And given the tight spaces
these things are in, etc, it definitely is not a trivial project.