We want to mount a water heater on a wall. The stability requirements are high - the heater will have over 100 kg total weight when full, and we're in a seismically active zone.
Unfortunately, when my father made the holes, he hit an electric cable. Here you can see the heater and the wall; the holes are in the upper-right corner of the wall. The cable is under the right-side hole.
The problem is that we will have to repair the cable, and then we won't be able to place the hole in the same position.
Normally, it would be enough to move around 10 centimeters from the old hole, and drill new holes. But this wall is built from large bricks, and we suppose they have a lot of hollow spaces. In the worst case, the brick could be of this type:
And as you can see in the doorframe, the builders placed the the hollows vertically. So now the drill hole goes through what is the z-axis on the single-brick picture. And we're worried that drilling a new hole too close to the old one will land in the same brick hole, and will weaken the brick too much.
At the same time, we don't really have another option for placing the heater. The mounting plate was attached to the heater by the manufacturer and can't be moved along the heater's body. The heater can't be placed away from the originally planned position: to the top, the ceiling is in the way. To the bottom, there are the water pipes for the heater. To the left, there's the bathroom door, and to the right, there's the wall. We also can't mount it on the wall to the right, because that's a weak drywall masking a ventilation shaft. So the only places we can drill new holes are within maybe 5 cm of the original holes, within the same already-weakened brick.
Is there a way we can strengthen the wall and make sure the brick doesn't break apart, now or in the future?


