Digital showers - min hot temp question

[Adam2]

In our old place we used to have a Mira digital shower - very pleased with it as worked well and the remote control thing you can put on a shelf so keeps the wall fixtures to a minimum.

 

In our new place we'd like the same but I noticed the instructions mention hot water temp range 55-65 instructions

 

What would likely happen if the hot is below this say 45? I can't see why it would be a problem as with a "regular" system wit the hot water stored at say 60 at times it would get below 55 and I'm sure the shower will still work. 

 

We'd like to store our hot water at 45/50 degrees range.

 

Appreciate any experience you may have on this or recommendations for other similar digital shower mixers if any have a better stated hot water inlet tolerance

[Nickfromwales]

1 hour ago, Adam2 said:

We'd like to store our hot water at 45/50 degrees range.

Store at 50/52oC and your troubles will fade away. 45oC is just too low, your cylinder capacity will be dire.

 

Just read the MI's you linked. That probably refers to the max input temp that it will tolerate / blend down reliably vs the minimum required to 'make hot water'.

Edited March 27, 2022 by Nickfromwales

[Adam2]

2 minutes ago, Nickfromwales said:

Store at 50/52oC and your troubles will fade away. 45oC is just too low, your cylinder capacity will be dire  

Yes could do - we've a 300L UVC and ASHP so looking to optimise efficiency when just the 2 or 3 of us here which is most of the time. We can always try that and up the storage temp if we experience issues with volume.

 

Though question remains really as 50 / 52 would still be below the range stated on the instructions which I guess they have there for a reason so just curious what the issue is with lower temp even at 50. Is it the mixing isn't so accurate or something?

 

Maybe we could have a simple life - store at 40 degrees and just have a hot pipe to each shower - save pipes and valve costs then 🙂   <- only a joke

 

 

[Nickfromwales]

6 minutes ago, Adam2 said:

Is it the mixing isn't so accurate or something?

Most likely. I'd put money on it working fine with a lower input temp.

7 minutes ago, Adam2 said:

🙂   <- only a joke

NEVER joke about something as serious as plumbing.  

[Gone West]

12 hours ago, Adam2 said:

What would likely happen if the hot is below this say 45?

At our last house we used to heat our 185 litre DHW tank to 45C with an EASHP. Our mixer showers and our bath thermostatic valve worked fine. Only two adults in the house and we never ran out of hot water.

[Temp]

It's possible it needs 55C hot water to achieve the maximum possible 48C output temperature under certain conditions. For example if the hot and cold water pressures aren't equal? Or if the cold is very cold in winter? If you never want it set that hot then perhaps lower flow temperatures still work.

 

I suppose someone should remind you about legionaries disease.

Edited March 28, 2022 by Temp

[Conor]

Our thermostatic bath tap said the same but works fine with ~40⁰c water. In fact all of our thermostatic taps say something like min 50 or 55c.

[Adam2]

great thanks - will crack on with that then an report back if issues