Mira Sport Shower

[Veggie Dave]

I'm off tomorrow morning to look at a Mira Sport that apparently produces hot water for a few minutes and then goes cold. I'm trying to think what could cause this fault while also looking at the schematic for the shower.

I'm thinking it's either the flow valve or the thermal switch that's at fault but I don't know how to check these components. I suppose it could also be the elements failing after they've come up to temperature, too.

Does anyone have any opinions or advice, please?

Thanks.

 

[Plamber]

Try changing over the shower head/hose to see how if that helps.
Or give the filter a clean out. these are the first things I try.

 

[Best]

Make sure the flow is not too low or restricted causing it to cut the heat.
The thermal cut out is, as far as I know, identical in all the Sport models. It is on top of the heater tank & is the first thing that the live wire goes through. It has usually torque screws, two of which do the wires either side of it & one holds it in place (other side just hooks in). They give a lot of trouble but usually fail totally.
It just needs checked for continuity with a meter but with power off the shower!
Do have the wiring at switch/pull cord checked for tightness.

 

[Veggie Dave]

Okay, the shower over heats after 10 to 180 seconds of use. There's no restriction in either the shower head or the shower hose. The thermo switch is working, all the electrical connections are sound.

As this is a very hard water area I thought it might be limescale in the heater tank but couldn't for the life of me work out how to check this ... so I phoned Mira, who confirmed that as the shower initially produced hot water that meant the thermo switch was working, and as the unit still over heated even with different shower hose and head, that the only other possibility is the heater elements are coated in limescale.

Job done. I thought I'd let you all know the outcome in case you come across anything similar.

 

[charlie11]

Hi. I'm having exactly the same problem, checked the filter which I cleaned out but no different,changed heads, still the same, I have not checked the thermo switch, going off what they told you if I am getting hot water then the thermo switch is OK. How did you fix the problem, did you change the elements or can you clean them.