Mira Orbis Shower Fault - can any one help?

[spitspot]

Hi

I have had a Mira Orbis Electric Shower for the last 4 years which has worked fine with no problems until a few days ago.

I noticed that our consumer unit RCD had tripped for all the circuits in the house. Upon resetting it and trying to have a shower the next day I noticed E1 flashing on the LCD of the shower. I turned the shower power supply off and on again and this went away. However when I tried to start the shower the LCD displayed 'Temp Limit' and the water flowed as usual but remained cold.

Reading the instructions the manual suggests that if 'Temp Limit' appears to run the shower for 10 secs then the heater will kick back in, but this does not happen.

I have replaced the thermistor as the manual suggests checking and refitting one if E1 is displayed. However this has not worked - E1 only appeared that one time anyway.

Any ideas? I contacted Mira who wanted to charge me nearly the price I paid for the unit to come out.

Any responses greatly appreciated.

Thanks.

 

[seco services]

Sounds like your thermal switch has activated on the top of the hea can.
Check it for continuity with multi meter.
Turn mains power off to shower to check.

The orbis thermal switch if activated needs replacing it's not a two stage tco like most others.

 

[spitspot]

Hi,
Thanks so much for your response.

I've put a multi meter across the thermal switch as you suggested. I got a reading indicating continuity which I guess is bad in the sense that the switch is working ok?

Any other ideas what could be causing the problem?

Many thanks.

 

[seco services]

Is the low pressure neon on/off ?
Is it stone cold when set to high and temp dial turned right up in the red ?

 

[spitspot]

Hi

I can't see a neon on, but I know there is a 'Low Flow' indicator on the LCD which is not being shown.

Yes, the water stays cold even on the high setting and turned up into the red.

Many thanks.

 

[seco services]

Right.
Next step is shower on high setting test to see if 230v is at the elements.
If so then isolate and test elements for resistance.

 

[spitspot]

Hi

There are two electronic switches/relays on the pcb. Mains leaves the thermal switch and goes into both switches. Each switch controls the mains power to each of the 2 heating elements.

So what I've done is:

With the shower on checked to see if 240v was across each switch. The multimeter read 240v across each switch indicating that both switches were still open and no mains was reaching either element. Which is bad?

I then isolated and tested the elements. Both read 13.5 ohms. Which is good?

So my guess is that the pcb controlling ( and containing) the relays is duff? Any other tests I can do? Is the correct diagnosis?

Many thanks for your time.

 

[seco services]

Right elements are ok.
If you watch the relays on pcb do none of them open/close when selecting from low, med, high ?
Have still got the back light on the shower working ?

 

[spitspot]

The relays are black and opaque so I can't tell by looking if they are moving. However I can tell that if I put the multimeter across each relay that no power is passed from either of them to either element when I switch the shower on. I've tested this on low, medium and high. Sorry I should have been more specific in my last answer, by 'switch' I meant relay.

The lcd backlight does come on when power is supplied to the shower. It flashes on and off when the shower is started.

Many thanks.

 

[seco services]

It flashes on and off when the shower is started.

What then stays off while shower in use ?

If i remember it should come on bright while shower in use and when turned off should dim for a few seconds while water flowing then water flow stops and light gos out.

What info is displayed on display when on ?

 

[spitspot]

The LCD backlight comes on when power is supplied to the shower.

When I press the large silver on/off button in the middle of the temp control the shower starts. At this point the LCD backlight flashes on and off continuously and the term 'Temp Limit' is shown in the LCD. The temperature in C which would normally be shown is NOT shown. Water flows as usual, it's just cold.

Pressing the on/off button again then turns the unit off. When this happens the water keeps flowing for a couple of seconds and the LCD shows a quick animation flicking through the segments of the LCD digits. When the animation finishes the water flow stops and the shower is off. All that is now shown on the LCD is the time.

The LCD backlight does not (or did it ever) dim when I press the on/off button to stop the shower.

 

[spitspot]

Sorry, should have added:

The LCD backlight comes on when power is supplied to the shower - it stays on, and does not flash on and off.

Only when the shower starts does the backlight flash on and off.

Thanks

 

[seco services]

With a few of the answers you have given ie tco has continuity, power to main pcb, no display i'm looking towards a faulty pcb, control pcb more than relay pcb.

But due to the age of the shower and not really been a great deal of issues with this shower in the past i would still be looking at a second opinion myself to be 100% sure rather than chuck money at it.
It's one i must admit has got me wondering.

But would be nice to know what is causing the fault if you do decide to call mira or have a go yourself.
I'll still see if i can tap someone elses brains this week.

 

[spitspot]

Thanks very much for you help with this.

I will definitely write back here to let you know the outcome, what ever that might be!

 

[spitspot]

Oh well, after getting 2 further opinions I decided to replace the relay PCB, only to find that this made no difference at all.

So now I'm looking at replacing the control PCB, but I am hesitating because this is getting rather expensive.

Mira have suggested I may have had a power surge which could have damaged several electronic parts - but that doesn't really help much.

I'll update with what I decide to do.