While using the shower today, the main switch of our consumer unit
tripped. It has an RCD and none of the individual circuit MCBs
tripped.

When I switched it back on and restarted the shower, everything seemed
OK, except that the shower is not heating properly now. It does heat a
bit, but it is as though it is on a lower setting than it actually is.

The shower is a Mira Sport (9.5 KW I think) and is about 7 years old.
It's in good nick cosmetically at least and I'd like to keep it if
possible.

Any ideas what the most likely problem is and anything I can test to
confirm? Are parts easy to come by?

Thanks in advance for help.

--
Bob

wrote in message
oups.com...
While using the shower today, the main switch of our consumer unit
tripped. It has an RCD and none of the individual circuit MCBs
tripped.

When I switched it back on and restarted the shower, everything seemed
OK, except that the shower is not heating properly now. It does heat a
bit, but it is as though it is on a lower setting than it actually is.

The shower is a Mira Sport (9.5 KW I think) and is about 7 years old.
It's in good nick cosmetically at least and I'd like to keep it if
possible.

Any ideas what the most likely problem is and anything I can test to
confirm? Are parts easy to come by?

Thanks in advance for help.

--
Bob


Sounds like the heating element is up the creak. Spares are easy to find on
the net. Element is about £60 + vat and delivery


--
Regards

Stephen Dawson
Fox Electrical Services Ltd
www.foxelectrical.co.uk

In article , Stephen Dawson
writes


wrote in message
roups.com...
While using the shower today, the main switch of our consumer unit
tripped. It has an RCD and none of the individual circuit MCBs
tripped.

When I switched it back on and restarted the shower, everything seemed
OK, except that the shower is not heating properly now. It does heat a
bit, but it is as though it is on a lower setting than it actually is.

The shower is a Mira Sport (9.5 KW I think) and is about 7 years old.
It's in good nick cosmetically at least and I'd like to keep it if
possible.

Any ideas what the most likely problem is and anything I can test to
confirm? Are parts easy to come by?

Thanks in advance for help.

--
Bob


Sounds like the heating element is up the creak. Spares are easy to find on
the net. Element is about £60 + vat and delivery

Just to add, the reason that it has dropped in power and not failed
completely is that these things invariably use 2 separate elements, one of
which appears to have failed. Each element should be in the range
10-12ohms so they're easy to check. As this one appears to have failed
with leakage to earth I'd be inclined to isolate it straight away.

Except for the electronically controlled ones these are very simple to work
on but be aware that you are combining a high amperage power supply,
water and naked bodies so best to treat them with respect.
--
fred
Plusnet - I hope you like vanilla

On Sun, 24 Jun 2007 05:51:05 -0700, wrote:

While using the shower today, the main switch of our consumer unit
tripped. It has an RCD and none of the individual circuit MCBs
tripped.

When I switched it back on and restarted the shower, everything seemed
OK, except that the shower is not heating properly now. It does heat a
bit, but it is as though it is on a lower setting than it actually is.

The shower is a Mira Sport (9.5 KW I think) and is about 7 years old.
It's in good nick cosmetically at least and I'd like to keep it if
possible.

Any ideas what the most likely problem is and anything I can test to
confirm? Are parts easy to come by?

Thanks in advance for help.


If it's like this:

http://www.showerdoc.co.uk/shower-spares/mira/mira-sport-upto98.htm

Then you might have encountered a very common problem with older Mira
showers.

If it's the later design like this then all bets are off

http://www.showerdoc.co.uk/shower-spares/mira/mira-sport-current.htm

Isolate the electricity and remove the front cover, put the shower
head/hose well out of the way to avoid any splashback.

Replace the knobs and turn the shower on to get water flow, as there
is no electricity feed there will be no heating.

Look for a leak/dribble running down the wiring. Chances are pretty
high that the pilot valve seal has leaked, the usual result being that
one of the micro-switches destroys itself. The complete valve assembly
(part number 419.87) including the micro switches is about 30 quid.
You'll need a torx screwdriver to change the valve.




--

On 24 Jun, 21:39, Matt wrote:

If it's the later design like this then all bets are off

Yes, it's this one, unfortunately:


http://www.showerdoc.co.uk/shower-spares/mira/mira-sport-current.htm


So you don't think it is reasonable to assume it is probably the
heating element like the others suggested? How about the fact that it
still partially heats? fred suggested that that was a symptom of one
of the parts of the two part element failing.

I'm in a bit of a quandary: I'd pay £60 for the element to fix it, but
it's a lot to risk if that isn't the problem, so I need to find a way
to diagnose the problem. If I get someone out to look at it, and it
is the heating element, it is not going to be cost effective by the
time call-out/labour charge is added. I may as well buy a new shower.

Thanks

Bob

On 24 Jun, 17:53, fred wrote:
Just to add, the reason that it has dropped in power and not failed
completely is that these things invariably use 2 separate elements, one of
which appears to have failed. Each element should be in the range
10-12ohms so they're easy to check. As this one appears to have failed
with leakage to earth I'd be inclined to isolate it straight away.

Thanks for the advice. Could you give some more details on how I go
about checking the element. | have a cheap multimeter thing but I'm
not much of an expert on using it. (Mainly just used it for
continuity testing.)


Except for the electronically controlled ones these are very simple to work
on but be aware that you are combining a high amperage power supply,
water and naked bodies so best to treat them with respect.

Which are the electronically controlled ones? Mine is this one as in
the link Matt sent:

http://www.showerdoc.co.uk/shower-spares/mira/mira-sport-current.htm

Thanks

Bob

If you look either in the handbook or on the Mira website you can get the
wiring diagram for the shower
http://www.mirashowers.com/onlinecat...60737_w2_a.pdf

In the illustrated parts diagram posted previously, the heater is item
416.34/35. There are two elements to the heater as shown on the wiring
diagram as "load". If you use your meter and measure the resistance (ohms)
accross the load, you will probably find one is high, and the other low.
Please remember to isolate power to the shower before you take any covers
off etc.

About three weeks ago, our shower, did exactly the same, tripped the MCB.
After resetting the MCB the shower was only producing warm water when set to
high, if set to med it produced cold water. But the heating element is
typically £60+VAT, so you have to work out if is it really worth paying for
a repair vs buying a new cheapo shower.

Vernon

In article . com,
writes
On 24 Jun, 17:53, fred wrote:
Just to add, the reason that it has dropped in power and not failed
completely is that these things invariably use 2 separate elements, one of
which appears to have failed. Each element should be in the range
10-12ohms so they're easy to check. As this one appears to have failed
with leakage to earth I'd be inclined to isolate it straight away.

Thanks for the advice. Could you give some more details on how I go
about checking the element. | have a cheap multimeter thing but I'm
not much of an expert on using it. (Mainly just used it for
continuity testing.)

Ok, excuse any condescension in the following, you've mentioned a bit of
newbness in this area so we'll go for some hand holding (don't worry, I'm
not enjoying it either ;-).

First the isolation, don't assume that any switch actually isolates the
shower unless you check that it does so with a meter following basic
checks. There should be a pull cord isolator in the bathroom or a heavy
duty switch outside, check that it really is the shower isolator by switching
on the shower and checking that the shower flow stops when the isolator
is switched off. I'd also switch off the dedicated switch (MCB) in the
consumer unit before working on the unit, again check that it is the right
MCB by switching on the shower and making it stop by use of the MCB.
Next use both the isolator and MCB to isolate the unit, if it's a pull switch
isolator (spawn of satan) I'd switch the shower on, pull the isolator, check
the shower goes off, then switch off the MCB. Then place some gaffa tape
over the isolator switch in the off position (or tie the cord up and out of the
way) and tape over the MCB in the off position. Why do this? Well, once
you've done it a few times and f'ckd up a few times it will become obvious.

Next put your meter on volts ac and check that it works. Not many ac
sources about other than a mains socket so that may be where you need
to check (hopefully this will be the most hazardous step). If the meter
doesn't show the expected ac voltage then don't trust it and stop. Also
don't follow this step (and stop) if your meter doesn't have shrouded plugs
into the meter and has features on the probes to stop your fingers slipping
closer to the bare points.

Set the shower on-switch to the off position and the temp control to 12
o'clock to aid re-assembly.

Place some gaffa tape over the drain (or experts stand with a foot over the
drain), remove screws and then the cover. Some units may have wires
connected to the front panel but yours appears not to. If there are wires, let
the panel dangle by the wires if they won't be damaged by the weight of
the panel or remove the switch or neon that the wires connect to after
noting where the parts are fitted.

Use the meter (still on ac volts) on the incoming supply at the obvious high
power terminal block to check it is isolated. If it is 0V or another small
number under 0.1V then continue.

The heater terminals will have obvious and heavy blue and brown wires
connected to them. Set your meter to measure resistance on its lowest
range (unless digital autoranging) and measure the resistance of the
elements. They should be between 10 and 14 ohms. Don't worry if the
elements have slightly different values, say one 10 and one 12 as it is
common for the manufacturers to give them slightly different ratings. If one
show open circuit it is bust.

If both elements show ok then check the manual and safety switches in
the case. There will be at least one over temperature cutout on the body of
the heater which will normally have a round body and will have heavy duty
connections running to it. It should show zero ohms in a continuity check.
I have seen a second temperature switch attached to the output pipe on
some Tritons which operated on only one of the heaters, reducing the flow
temperature in case the flow is set too low (temperature dial set too high).
If you have one of these then check it for zero ohms too.

Unless the unit is electronically controlled then the power to the elements
is likely to be controlled by high current microswitches operated by cams
on the on/off/power-setting switch. Check these are working by measuring
continuity between the main live feed (at the terminal block) and the live
feed to the elements. In the heat position 1 there should be continuity to
only one element and in heat position 2 there should be continuity to both.
There may also be a mechanical interlock which stops the heater
microswitches being operated unless the shower is powered up and water
pressure is present via the incoming water control solenoid being enabled.
If an interlock is present its operation should be straightforward to work
out, operate the interlock manually or find a way of actuating the
microswitches manually to permit testing.

Always check the condition of the wiring in the unit, due to the high
currents involved even minor loose connections can result in overheated
and damaged wiring. If wiring or any connector shows sign of damage due
to overheating then it is wise to replace that part of the loom. If you aren't a
competent solderer and capable of rebuilding a loom using high current
connectors, buy a new loom from the manufacturer.

From the above you should be able to work out where the failure in your
unit has occurred. Buy the bits and repair it yourself (taking care to rebuild
exactly as it was originally made) or get someone in to complete the job.


Except for the electronically controlled ones these are very simple to work
on but be aware that you are combining a high amperage power supply,
water and naked bodies so best to treat them with respect.

Which are the electronically controlled ones? Mine is this one as in
the link Matt sent:

See the notes :-), yours doesn't appear to be. These units are built to a
cost and really aren't that complicated, follow the diagrams and the build
should become clear.

http://www.showerdoc.co.uk/shower-spares/mira/mira-sport-current.htm

Notes:

1. Normal digital multimeters will not show a resistance of less than 0.2
ohms, this is due to the contact resistance of the probes or the surface
they are connecting to, treat 0.2 ohms as zero and if you get a reading of
0.4-0.6 then try applying a bit more pressure to the contact between probe
and test piece, it will often reduce the contact resistance.

2. In my experience, electrically heated showers commonly use high
current V3 microswitches to switch power to the heating elements. These
are available at low cost (2GBP or so) from such locations as
http://rswww.com who are a trade organisation but will deal with the public
via their website for home delivery. It is important to source high current
(20A) switches as these components are normally supplied in 5 or 16A
ratings. Use of inferior 16A switches will result in overheating damage to
connectors and wiring looms leading to an expensive repair.

3. Electronically controlled showers can be identified by the presence of an
overpriced circuit board which has more space dedicated to the provision of
unnecessary flashing lights than to clever electronics to maintain the
comfort level of your shower. Electric showers are second best (to gas or
oil externally heated water showers) and these electronic controls do
nothing to change their position in the pecking order.

If anyone's still awake after that, I hope it helps.
--
fred
Plusnet - I hope you like vanilla

On 25 Jun, 20:23, fred wrote:

If anyone's still awake after that, I hope it helps.
--
fred

Thank you very much - that was great help and I'm sure others will
find it useful in the future.

I was able to confirm that it is indeed the heating tank that is the
problem.

Thanks again.

Bob