Just wondering if I'll need to have a tempering valve installed when replacing existing electric HWS with new heat pump HWS?

It's almost in the same location but not quite. 1 - 2 metres away from the old tank under the house (it's a split system heat pump I'm looking at so tank indoors is fine).

I could put it in the same location as the old one if I really had to but that would make the job much harder - need to dig down to get some extra height for the new tank as it's taller than the old one. Seems easier and less inconvenient to just relocate it where there's already more height and extend the plumbing to suit. That way I can get the concrete slab done first too whilst the existing HWS is still in place and working.

I don't really want a tempering valve, there are no children or old people in the house and I quite like being able to fill the hot water bottle from the bathroom tap with 60 degree water. But if the law requires one to be fitted then so be it.

If I do need to have one of these valves, can anyone confirm my understanding that it needs to be for hot water going to the bathroom only? That is, I can still have full un-tempered hot water (60 degrees) in the kitchen and laundry? Also what about the sink in the garage - does that need to be on the tempered supply or not?

All the pipes are easily accessible under the house (it's high enough to stand up under nearly all of it) so it shouldn't be hard to do any necessary pipe work. I just want to know exactly what is / isn't allowable before the plumber turns up for a quote.


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