Thanks for your help. When you say temporary, does that mean months or years? Also, it looks like the rebuild kit is about $60 and the full head replacement is $250. Would the full head replacement be the permanent fix or is the entire unit flawed?
Choices are
new softener vs full head replace vs rebuild kit
with a new softener most likely to solve the problem but it is the most costly solution.
What probability, P, from almost 0 to almost 1, would each have to have for this decision to be a toss-up as far as cost?
The three likelihoods have to add to 1.0.
In order,
new softener vs full head replace vs rebuild kit
is ranked from most likely to fix to least likely to fix. Let's say the prices of these options are $600, $250 and $60, respectively.
Let P be the likelihood you waste your money on something that doesn't work and I give the first choice a P value of 0.05. Almost certainly a new softener will fix the problem for a long time.
Formulas are great but spreadsheets provide a sanity check. Here's mine.
Option \/ P(not working) Part cost \/ likely cost \/ P(working)
new soft 0.05 .....................$600.............. $30 0.95
full head 0.12 .....................$250.............. $30 0.88
rebuild 0.88 .....................$60................$53 0.12
new soft 0.05..................... $600.............. $30 0.95
full head 0.195..................... $250..............$49 0.805
rebuild 0.805..................... $60.............. $48 0.195
new soft 0.05 .....................$600................ $30 0.95
full head 0.5..................... $250............... $125 0.5
rebuild 0.5..................... $60................. $30 0.5
In the first, a full head is a good option providing it has at least a 0.88 chance of working.
In the second, with those probabilities, a new softener is the choice.
In the third, a rebuild kit is the choice if it has at least a 0.5 chance of working.
Forum members can provide probabilities based on experience (which I don't have). Then it's just number crunching.