Yes - there was hidden access to the pump for the whrilpool tub since two sides of the tub are on exterior walls and the third one was adjoining the shower. We created an access panel using tile on the front apron of the tub and used grout caulk to secure it in place.

why did not u use the exterior wall, we have the same situation, apron has been already tiled, and idea is to open from exterior for faucet on one side and motor on other?
Any pros or cons and what is the best way to configure if exterior wall?
May I speak with you for consultation.

Our project was on a second floor, so we did not want to use an exterior wall for access so we planned it accordingly prior to tiling the apron. The main reason for access is for pump and the electrical connection for the pump (i.e. if the GFI outlet trips), so we did not want to have to get into having the homeowner get on a ladder, remove siding etc. just to reset a GFI or to perform maintenance on the pump should it become necessary. In addition, depending on where you are located, you may be exposing yourself to having the pipes freeze or making the tub uncomfortable if you compromise the exterior insulation with an access on an exterior wall. Most faucets nowadays can be serviced without needing access underneath, so that may not need to be a consideration. As i mentioned, there are a lot of considerations for creating the access on the exterior, so I would work with your contractor to find a creative solution if you go that route - one that will provide access and not compromise the waterproofing or insulation value of the exterior wall. The best bet given those considerations may be to bring in a tile installer to take a few tiles off the apron and to create an access that way. These types of solutions are best worked out on site , so it is probably best to look to the person who will do the work to come out, assess the situation and help you determine the best solution. Hope this info helps!