Re: Water impeller in a Johno 175
Easy - If you haven't replaced it within the past 2 years - just do it. A water pressure guage is a good indicator but useful only over time. For example if you replace the impeller and get a reading of 14 lbs WOT and a year later it reads 8 lbs you are probably ready. On the other hand if it reads 12 lbs you can probably go for another year.
