It quite simple really. You have PF advising what Shurflo originally stated - no warranty on any pump that has been used for windowing cleaning on any hose of smaller diamt than 1/2". They are covering all the bases. If the pump failed when PF had already advised the customer against using small bore hose then a replacement pump is for the customer's account - its not a warranty claim.
Then you have the window cleaners that ignore the advise or never heard it in the first place, that just do it.
When you have designed a trolley like PF have they want to use the smallest, hence lightest battery, for the job. If you come along and use a much smaller hose then a fully battery charge might not last the day.
I have recently posted that using the same flow rate with 100m of minibore and 100m of microbore hose, my pump drew twice the amount of current from the battery using microbore. That extra current draw from a 110 amp leisure battery is negligible but from a 12 amp battery is a totally different story.
Its the same as a newbie asking a question on here. He might ask if its ok to clean a window whilst standing on a flat roof. The H&S regulations say no as the flat roof should have safety rails around it. That's the correct answer. Have we cleaned a window off a flat roof? Yes. Would we advise someone else to do it? No.
