You did good work for two hundred people last year. Nearly all of them were happy. Eleven of them left you a review, and four of those were the same week you remembered to ask.
That gap is not a reflection on your work. It comes down to three things you can control — when you ask, who asks, and how much effort the customer has to spend. Fix those and the trickle turns steady.
A happy customer is not a motivated customer
Satisfaction does not produce action. Two things reliably make somebody write a review: being annoyed, or being asked. Only one of those is available to you, and most contractors are quietly relying on the other one not happening.
Timing, the ask, and friction
Timing: within a couple of hours of the job finishing, while the relief of having hot water again is still fresh. By the next morning it is just a thing that got fixed. Four days later it is nothing at all.
The ask: from the person who did the work, using the customer name and something specific about the job. A message that could have been sent to anybody gets treated like one. Friction: exactly one link that opens the review box itself. Not your homepage, not a login screen, not an app download. Every extra tap costs you a proportion of the people who genuinely meant to do it.
What about the ones who are not happy?
Ask them too. Filtering your review requests so only the pleased customers get the link is called review gating, and Google prohibits it — the risk is not theoretical, and it is not worth it. What you can legitimately do is make it easy for an unhappy customer to reach you directly and fast, so the problem gets fixed before it becomes the thing they sit down to write about. Fix it properly and a fair number of them will happily leave a review afterward. That is earning the outcome rather than hiding from it.
What good looks like
Not a burst of thirty reviews in one week, which reads as bought and often gets filtered anyway. What you want is a handful every month, so the newest one on your listing is always recent, and a short reply from you underneath each one — including the critical ones, especially the critical ones. That is what somebody comparing three companies on their phone is actually reading. Hired Hands sends the ask automatically when a job is marked done, and routes unhappy replies to you rather than into the void.