Any updates on temperature daz?
With your hose coiled on the reel you should see a much higher reading.
Also are you sure your heater isn’t stopping and starting during your work? If I’m Right in saying you didn’t get a second pump fitted to constantly recirculate and keep the heater running. I heard someone else in here mention within about 2 minutes of having the water flow stopped, there heater goes into shut down.
it was reading 44c when coiled up on the reel after the heater had been running for 20 mins(return to tank)on my way to work but with 90m of hose out this afternoon its only warm at brush end not hot due to losing a shedload of heat through the hose.
i expect the water to be a lot hotter in the warmer months but in winter warm water is all im gonna get apparently(with most of my hose off the reel.)
im just glad i didnt go for the 5kw heater as i reckon it wouldnt even get warm at the brush end.
I wonder how much extra heat you would be getting if you had a second pump Fitted or had a pressure relief valve fitted.
In my mind that seems the best option. So you turn water off with the univalve, the pressure builds up, which in turn opens the relief valve, and hot water starts going back to the tank.
That would then mean your tank water would start to heat up, giving you a hotter header tank, and In turn hotter water at the brush head.