Flow rate and reversibility.
I was the first independent in my area to have a Kamco over 20 years ago. I had started to lose work to BG on the strength of their PF'ing. I used it on all installs, but was never totally convinced that it wasn't just smoke and mirrors, compared to the "standard" chemichal flush, although the black stuff was impressive. In those days most of my jibs were BBU's out, heat only in. There were some dirty systems!
I got called to a noisy system which was a replacement BBU. The punter had declined a chem. flush.
I was honest with him, and told him that I had not yet used it to cure a specific problem. I was not going to do it free, but said that of it was not totally successful, I would just charge him half price. It was a part of my learning curve. Anyway, did the job as normal, but left it running through the HEX over lunch, so a lot longer than normal, TBF.
On my test before, it was so noisy he could not hear the TV, it was ridiculous. Afterwards, we fired it up, and had a coffee in the dining room, on the other side of the boiler wall. With the boiler up to temp, we could hear the clock in the lounge ticking. Amazing.
I got paid in full.
I sold the unit many tears later, as I had stopped doing heating, concentrating on fires. Eventually I bought the bigger Kamco on wheels, cost over a grand with all the bits, bit only used it about 4 times before becoming ill. Went to use it a couple of years later, and the motor was knackered, having been in my shed. So, yes, hiring is a good idea - but the hire shop will not have plenty pf connections. Over time of owning and using, you accumulate different fittings to get you out of trouble and make life easier.
One thing to note: they do not normally have an auto feed valve, so you have to keep a close eye on it. I started using a large seedling tray to stand it in, just in case, but stress levels were too high. I then invested in longer hoses, so the unit was outside.
Oh, and use the Kamco chemicals - FX2
