Edd, instead of pre-heating your tank of water, why don't you draw hot water from your heater and mix it with cold water drawn from your tank to produce a lower temperature through your hosereel, or do you?
As you know, I have an Omnipole hot retro fit system, I only use it for drawing hot (60degree) water straight from the heater to the hosereel for new cleans , etc when it's justified. The rest of the time I'm happy using cold water because it's cheaper than wasting diesel to heat the water.
I have found that by recycling hot water back into the tank my pumps don't last as long as they should because the hot water plays havoc with them. Warm-ish water isn't so bad going through the pumps. Do you find you have problems running hot water through your pumps?
The only time I recycle hot water back into the tank is on very cold evenings during the winter in case everything may freeze up overnight and during early mornings.
Do Ionics pay you for advertising their system? Do the general public really recognise that trademark logo? Is that logo on your van really attracting new customers who know the difference between systems as I'm really curious.
I know how you feel about being without your van. I was without mine for 2 days this week whilst it was going through an MOT, full service and waiting on DHL to send some parts which they totally messed up, so that cost me an extra day off work.