Didn't someone on here once buy a 12lpm heater a number of years back? He didn't have enough flow to ignite it using a 5lpm pump.
However, as Slack has a higher delivery pump it may just work for him.
The 8 liter unit is a 16kw boiler whereas this one is a 24kw boiler. It will use more gas and will heat the water inside more quickly even at a faster flow.
The viscosity of water changes when it gets heated. I found that we got more hot water through the hose and brush heads than we did with cold (9 degrees) using the same controller flow settings. So you might have an issue getting the heater to ignite when the water is cold in the hose reel. You can also only get so much water through minibore hose no matter how 'big' the pump is.
I think it will be one of these suck it and see. Slack is thinking of going where no window cleaner has been before.

Personally, my gut feeling says to me that the heater is too big for our application, but I don't have an experience with faster flow pumps being used in this situation.
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