Mira 416.41

A: 

Weare having a problem at the moment with our ticketing system it is runningwords together, we have people working on it!!

 

Iam afraid you can’t reset the thermal switch it needs to be replaced.

A: 

If the shower is absolutely cold then I thinkyou may have a faulty Thermal Cut Out

A faulty TCO will have no continuity across the two terminals(The black thing on top of the heating tank)

Therefore a good TCO will have power at both connections and afaulty TCO will have power at only one.

(The function of the TCO is, if the water over heats it cuts thepower off to the elements)

See Video.

http://www.youtube.com/user/showerdoc#p/u/2/_zi8JbEMYMs

 

Ifthere is some heat it may be a faulty element in the heating tank (there aretwo, three in most 10kw showers) you can check them with a multi meter youshould have a reading of around 12>18 ohms.

If you have power to theelements and no heat it's probably the elements, no power to theelements then it's probably a micro switch.

 

If you don’t have a multimeter we sell them at £10 each with a guide on how to use them for checking andtesting the various parts of your shower.

 

Apart from helping to fix yourshower, they are really useful for checking you have a power supply toappliances, for checking fuses, letting you know much power you have left inbatteries

(so you know if they are dud ornot)  and lots of other jobs, in short they are well  worth the £10.

 

http://www.showerdoc.com/installation/electrical-products/SKYTRO-600-005-Digital-Multi-Tester

 

A: 

The things to check first are.

1 That the main valve coming into your house is fully open.

2 Then check that the valve on the line to the shower is fully open.

If these valves are not fully open then there may not be enough water
getting to your shower to open / close the safety device that allowspower through to the elements

You don’t mention which showeryou have however the other possibility is a faulty pilot or flow valve

A: 

If when the shower was switched off did you hear itcontinuing to heat (Noise like a kettle starting to boil) this will mean thatthere is a switch or a relay that is stuck in the on position, this is keepingan element energised and this is probably what caused the original and the new TCOto fail.

 

It would unusual for a new TCO to fail for no reason.

If you heard no noises coming from the shower then we will replacethe TCO, however we will test the original TCO when it is returned.

If you do wish to return it please send me your invoicenumber and contact details to gt(at)showerdoc.co.uk

A: 

Issue = no H/W;flowLEDoff; ~13.4ohms on 2 back Neutral posts to each of 2 front posts of tank.(Assume this OK?)

Sounds OK

 

How test 2 microswitches(872.01,28) ?

 

Check for continuity, push button in continuity let button gono continuity

 

Or how test flow

Rough check turn flow up and downthe flow should modulate.

and switch assemblies(1563.507,509) ?

See 1 Above

(3) Continuity oninstalled TCO gives none.

= TCO faulty

Take TCO off and now saysok!

Can’t explain that! Unless it has something to do withthe “paste”

Being confused I look topof tank where TCO sits and 3/4mm dia blob of white grainy paste. I thoughtthermal conductive paste (like on PC cpu to heatsink).

No thermal transfer paste used onthis unit, more likely to be residual flux that wasn’t cleaned away.

Then notice on undersideof TCO the disc pushes into TCO body.

This is correct

Pushed in and loosecontinuity and at rest gain continuity.

Pushing the bi-metallic disc inis the best way to damage a TCO!

 

 I surmise that paste is some sort of buildup?I'll just clean TCO and tank top and reassemble.

Definitely worth a try

(4) But... HOW does heatfrom tank top cause this disc to move upwards into TCO causing loss ofcontinuity/power cut off?

I was expecting sort of bi-metallic sort of heat sensing setup...

The Disc is Bi-metallic

A: 

You don’t mention which model of Sport you have, However......

 

 The things to check first are.

1 That the main valve coming into your house is fully open.

2 Then check that the valve on the line to the shower is fully open.

If these valves are not fully open then there may not be enough water
getting to your shower to cool it properly the overheat safety device will turn
the power off until it cools Then it all starts again

Make sure that the shower head is clean and clear, that the hose isn’t kinked (this can happen just behind the hand set where it is difficult to see) also check the inside of the hose although it can look OK on the outside it could have collapsed internally

If all of these are OK then you are going to need a new pilot valve if you have the older model and a new flow valve if you have the newer Sport

A: 

Sorry we don’t have wiring diagrams for this shower you could try Mira directly  http://www.mirashowers.co.uk/home.htm or if you send us a few photos we may be able to work out what goes where.

A: 

Here is how to check the Thermal Switch/Thermal Cut Out

A faulty TCO will have no continuity across the two terminals (The black thing on top of the heating tank)

Therefore a good TCO will have power at both connections and a faulty TCO will have power at only one.

(The function of the TCO is, if the water over heats it cuts the power off to the elements)

See Video.

http://www.youtube.com/user/showerdoc#p/u/2/_zi8JbEMYMs

 

A: Sounds as though the thermal switch is operating correctly and the problem is not enough flow through heating can.
Check that hose is not kinked or collapsed internally and then shower head is clear.
Check that mains stopcock and any isolation valve in the feed to the shower are fully open.
Check that inlet filter is clear.
If all above are ok the it is either the pilot or flow valve at fault depending on which model of Sport you have.
If you click on the link below it will take you to our Mira page and you can identify your model and order the part required online.##

http://www.showerdoc.com/shower-spares/mira

A: As long as it is post1998, if an earlier model then you need part no 872.30.

Alastair