Heat pump cylinder in outhouse in Scotland

[Islander]

My landlord's great at getting all the Scottish government funding that's going, and there's full insulation, double glazing, an airsource heat pump and a Mitsubishi Ecodan unit.
The Mitsubishi installation manual says in big letters "The cylinder unit MUST be located indoors and in a frost free environment, for example in a utility room, to minimise heat loss from stored water". It's a big hot water cylinder at 63 degrees and it's been put in an outdoor coal bunker.
I expect that voids the Mitsubishi warranty but are there any actual rules and regulations being broken here? I don't want to bash the landlord (I love the landlord...) but they've already done this in 3 houses, they're planning to carry on doing it, and I'd like to get it home to them that this is maybe not such a great idea. Also I'm hoping to be here for 20 or 30 years, so that's a lot wasted electricity.
I'm getting temperatures of 23 degrees in the coal bunker when there's minus 5 outside, snow on the ground and an (economical) 14 degrees in the house.

 

[ShaunCorbs]

Main issue is freezing pipes so need to be insulated and you’ve said it doesn’t go below 20 when it cold out side so your fine

 

[Islander]

Main issue is freezing pipes so need to be insulated and you’ve said it doesn’t go below 20 when it cold out side so your fine

Hi Shaun,
The big one for me is that I'll be paying to heat my outdoor coal bunker to 23 degrees in midwinter for the next 20 or 30 years. (And about frozen pipes, the Ecodan cylinder unit often goes into shutdown mode and has to be manually reset, powercuts are frequent here, especially in winter on this Scottish island. In the house, there's always candles and the woodburner. In the coal bunker, there's just the Ecodan unit and some scrap metal.)
Anybody know what the regs are about installing a hot water cylinder in an outhouse?

 

[ShaunCorbs]

Hi Shaun,
The big one for me is that I'll be paying to heat my outdoor coal bunker to 23 degrees in midwinter for the next 20 or 30 years. (And about frozen pipes, the Ecodan cylinder unit often goes into shutdown mode and has to be manually reset, powercuts are frequent here, especially in winter on this Scottish island. In the house, there's always candles and the woodburner. In the coal bunker, there's just the Ecodan unit and some scrap metal.)
Anybody know what the regs are about installing a hot water cylinder in an outhouse?

There’s no regs just need to insulate the pipework

 

[Islander]

There’s no regs just need to insulate the pipework

OK, thank you