So, we thought about getting a motor pump to strengthen the water pressure. That will be our main focus and goal to make the shower works at its best. We're not sure if the old heater has a contributing negative effect on the shower because the heater wasn't functioning as well. It sparked several times the last time we used it, so we don't wanna take a risk to continue using it. So, this leads us to do another upgrade by buying a better heater with good quality. It is a bit pricey, but as long as we are getting our money's worth, we wouldn't mind.
This plan is still on the wait, until we can get back to the engineer who's currently out of town as of the moment.
More updates later...
Here are some things we have on our mind! :)