Try this
- Use a short acknowledgment rather than listing reasons the person should not appreciate it.
- If the task cannot become regular, state that limit separately so accepting thanks does not imply a standing commitment.
A worked example
“You’re welcome. I was glad I could help today; I won’t always be free on Fridays, but this one worked.”
An invented example to adapt, not a real exchange or a script you have to follow.
Before you leave it here
You do not need an equally warm response on command. A simple acknowledgment can close the exchange without creating another emotional task.