Low pressure on Mira electric shower when making it colder

[Little Badger]

I've got a very strange problem with my Mira Sprint 8.5Kw electric shower.

The water temperature is way too hot so I try to make it colder by turning down the temperature control and the low pressure light comes on making the water goes tap mains cold.
If I turn the temperature control back up the Low Pressure light goes off and the water temperature becomes scalding.

This is opposite of most peoples reported problem.

If I turn the power setting to one and turn the temperature control to maximum heat it works fine but is now not hot enough as Winter approaches. This way was fine during the summer.

Can anyone advise me what is wrong?

 

[terryplumb]

With both heating elements on high setting ,and the temperature control knob turned fully anti clockwise ,what's the temperature like ,not hot enough ?

 

[Little Badger]

With both heating elements on high setting ,and the temperature control knob turned fully anti clockwise ,what's the temperature like ,not hot enough ?

The Low Pressure lights comes on and the water goes mains temperature.

 

[terryplumb]

If you then turn it ,a little bit at a time leaving several seconds for stabilizing, what's the result ?

 

[Harry Bloomfield]

Sounds like not enough pressure, or not enough low to satisfy the Mira.. As it always been like that, are there any valves not fully open?

 

[Little Badger]

If you then turn it ,a little bit at a time leaving several seconds for stabilizing, what's the result ?

If I turn it up a bit at a time eventually the Low pressure light will go off and the water becomes scalding hot.

It's never been like that and it used to work fine.

I'll check my water meter stop cock in the morning.

 

[terryplumb]

Sounds as though there is not enough flow . Take the shower head off the hose and see if its any better. Head may be restricting flow with limescale build up.

 

[Little Badger]

Sounds as though there is not enough flow . Take the shower head off the hose and see if its any better. Head may be restricting flow with limescale build up.

Done that already. The problem is still there with the hose taken off.

 

[terryplumb]

You could check the inlet filter ,but before doing that measure the flow rate,shower head removed ,temp knob fully anticlockwise and heating elements Off. Direct hose into a bucket ,turn shower on ,time for 1 minute and then measure how many litres of water in the bucket. Let's know result.

 

[Little Badger]

You could check the inlet filter ,but before doing that measure the flow rate,shower head removed ,temp knob fully anticlockwise and heating elements Off. Direct hose into a bucket ,turn shower on ,time for 1 minute and then measure how many litres of water in the bucket. Let's know result.

I can't turn the heating elements off. I can only select position one as the minimum but if the Low Pressure light comes on then all heating elements will switch off.

 

[Harry Bloomfield]

I can't turn the heating elements off. I can only select position one as the minimum.

Position 1 and set minimum temperature, that will maximum flow..

 

[terryplumb]

The power selector knob ( top one ) has three settings on Mira sprint ? Fully anti clockwise is cold . but it doesn't really matter ,its the lower knob that controls the water flow ,fully anti clockwise.

 

[Little Badger]

The power selector knob ( top one ) has three settings on Mira sport ? Fully anti clockwise is cold . but it doesn't really matter ,its the lower knob that controls the water flow ,fully anti clockwise.

It's a Mira Sprint.

 

[terryplumb]

Sorry typo !! Meant sprint. This model has been around some time and has a few versions ,but the flow rate info is the same as I said earlier.

 

[ianmcd]

http://resources.kohler.com/plumbin...int-2006-2015-installation-and-user-guide.pdf