[NWH]

Yeah I think his is but the probe should be at the coldest section of the van my hose automatically empties into the tank as I plug into a large female Rectus fitting sometimes between jobs and on cold days when we’ve finished work.

[Spruce]

My Heatwave's cabinet is made with stainless steel. I'm surprised how little heat it gives off when it's been running a while. The cabinet is warm to the touch, but not hot.

My 650 litre tank runs across the width of my van just in front of my rear axle. This gives me space between the tank and rear doors for my hose reels. It also gives me space between the front bulkhead and my tank where my diesel heater is located. My Frostat on my heater kicks in when the temperature inside my heater drops to 3.1 degrees C. But I doubt in very cold weather the heat radiated from the cabinet would be enough to keep the hose reels at the back from freezing up. So I have an 800 watt electric heater, also with frostat control, to look after the back where the hose reels are.

When your frost stat kicks in does it not circulate hot water through the reels and back to the tank ?

I haven't set it up that way. The heater kicks in a 3.1 degrees and switches off when the water inside the internal hot water circuit reaches around 80 degrees c.

[Spruce]

It does circulate through the reels but if the probe is not in the right place the reels can get colder quicker.

I think spruces set up might be different to  yours and mine as he made it himself

True.