Mira electric shower problem

izzitme

ThisIsWeird said:

Izzitme.
The 'Go' has a wee on/off button on the front, yes? In which case, if water flows when this wee button is pressed, then it's clearly receiving power.
Could you confirm:
1) the isolator switch has a red light that comes on when 'on'? And is off when 'off'?
2) this red light remains on when you then turn on the Mira?
3)  you have tried every power level setting, and every flow setting from min to max?
4) at max flow - ie coolest setting - the water spray coming out the handset is powerful?

Hi.

Answers to 1 2 3 are yes they work as expected.

4. At coolest setting the flow is powerful then slows as dials are moved to hotter settings.

ThisIsWeird

Thanks.
Ok, not much left, then! 
Hmm, I wonder if Victor is on to summat? 
If you are careful, you can remove the front cover, make sure the hose is low and firing downwards, and turn the shower on. You can then observe the operation of the microswitches.
I'm not familiar with that specific model, but the usual procedure is that the 'on' button opens a solenoid valve to allow the water to flow, and a pressure switch inside is activated by this flow, and physically operates a microswitch to turn on the elements. This operation is usually very visible - you'll see a lever move, and hear the switch go 'click'.
Examine pics and diagrams of that shower first, so you can ID the parts.
Clearly this is risky, so only if you KNOW what you are doing.

victor2

It was many years ago (like at least 10) with ours. It was a MIra Sport with Airboost and the cold water feed in at the back, but it had to come in at an angle and not through an elbow, as that would reduce the flow rate. I suspect it might have been a common issue with that model, as the engineer went straight to it.

danrv

Maybe thermal cut out switch?
Old post here with similar problem.
https://forums.moneysavingexpert.com/discussion/3523585/mira-sport-electric-shower-running-cold

GDB2222

danrv said:

Maybe thermal cut out switch?
Old post here with similar problem.
https://forums.moneysavingexpert.com/discussion/3523585/mira-sport-electric-shower-running-cold

It’s strange to be happening on a second unit, though.

ThisIsWeird

Any developments, Izzi?

This is what I was thinking of - inside the shower is a water-pressure-controlled lever which will activate the microswitches to turn on the actual heating elements.

Do your insides look like this:

If so, then the actuator is part 11, and I'm guessing that the two wee arms (orange arrow in top pic) move up when water begins to flow. Do they on yours? (Bearing in mind the exposed leccy situation...) If you know what you are doing, and are confident you'll be safe, then you can check to see if these two arms move up and 'click' the microswitches.

twopenny

I'm guessing you've tried the flow rate on high and put the temperature up higher?

Seems simple but I was running around under mine trying to get wet and warm water.
I'd fiddled with the knobs but it was a plumber who stuck it on high flow and I changed the fancy shower head for a simple one and success!
Not enough flow for the fancy all singing all dancing shower head.

It also takes longer to heat in cold weather as the pipes run through the loft.

But that micro switch sounds like the best bet.

izzitme

ThisIsWeird said:

Any developments, Izzi?

This is what I was thinking of - inside the shower is a water-pressure-controlled lever which will activate the microswitches to turn on the actual heating elements.

Do your insides look like this:

If so, then the actuator is part 11, and I'm guessing that the two wee arms (yellow arrows) move up when water begins to flow. Do they on yours? (Bearing in mind the exposed leccy situation...) If you know what you are doing, and are confident you'll be safe, then you can check to see if these two arms move up and 'click' the microswitches.

It is all a sealed unit so I cannot see the microswitches

victor2

izzitme said:

ThisIsWeird said:

Any developments, Izzi?

This is what I was thinking of - inside the shower is a water-pressure-controlled lever which will activate the microswitches to turn on the actual heating elements.

Do your insides look like this:

If so, then the actuator is part 11, and I'm guessing that the two wee arms (yellow arrows) move up when water begins to flow. Do they on yours? (Bearing in mind the exposed leccy situation...) If you know what you are doing, and are confident you'll be safe, then you can check to see if these two arms move up and 'click' the microswitches.

It is all a sealed unit so I cannot see the microswitches

Can you return the second one and get another?

Or, if it is covered by warranty, will MIra send someone out to look at it, at no cost unless they determine it was incorrectly installed?

Didn't you have to to open the case to mount it on the wall and make the water and electric connections?

izzitme

victor2 said:

izzitme said:

ThisIsWeird said:

Any developments, Izzi?

This is what I was thinking of - inside the shower is a water-pressure-controlled lever which will activate the microswitches to turn on the actual heating elements.

Do your insides look like this:

If so, then the actuator is part 11, and I'm guessing that the two wee arms (yellow arrows) move up when water begins to flow. Do they on yours? (Bearing in mind the exposed leccy situation...) If you know what you are doing, and are confident you'll be safe, then you can check to see if these two arms move up and 'click' the microswitches.

It is all a sealed unit so I cannot see the microswitches

Can you return the second one and get another?

Or, if it is covered by warranty, will MIra send someone out to look at it, at no cost unless they determine it was incorrectly installed?

Didn't you have to to open the case to mount it on the wall and make the water and electric connections?

@victor2

I will have to get MIRA out to it I think. Yes the case was opened to make connections.

Baffling that it worked OK upon installation but then goes permanently cold.

Thanks everybody for the advice & suggestions. I will report back when the mystery is solved.