I'll need a cylinder that fits into my cloak/thing room 65x140cm space, its slightly bigger than that in places but 65-75cm once past some existing and unmovable gas piping to the neighbour above. So there seem to be a few options, slimmer ones etc.

 

My water use seems to be 10 cubic metres a month, I'm on a water metre. I use the shower daily, its just a mixer from combi boiler so not a power shower. I back off the water rate a bit when showering as I know this will save water and cost of heating the water. I did measure the current flow rate to be 6L/min, it could probably go double that at full whack, so based on that I roughly need 60 litres for a 10 min shower, I should probably x2 or x3 that for when I have someone staying over. Maybe over spec it to 200L or is that too much?

 

Do ASHPs have an option to do a weekly higher temp fill to say 55C-60C to kill off legionnaires - rather than using the cylinder heater with a COP of 1? or would this be a manual setting change (ie never gonna happen)? Or is once a week 50C water to 60C, not too bad in terms of cost?

 

I take it I would set the hot water to get reheated around midday to benefit from the warmer air outside. On that note my garden is north east facing and can be nice but from midday onwards is increasingly in the shade - does that mean I'll get slightly lower COP than if this was south facing?

If you look on the Cylinders2go website ( I get all of mine there through Trevor, as have many others on here ) there are all of the sizes and dimensions. Remember to look at HP UVC's not regular ( gas / direct electric ) units as the coils and sizes are different vs capacities.

 

You get the purge cycles with most HP controllers, however on a sealed system in this day and age, most consider it to be unnecessary.