Mira Sport shower - boiler removal

[Bob2016]

Hi

My 8 year old Mira sport is running hot then cold then hot. It started doing it about a week ago very intermittently but now it is almost a continuous hot/cold/hot cycle from switching it on.

Living in a hard water area I suspect it may be limescale build up so was trying to remove the boiler to descale before biting the bullet and replacing the complete shower.

Is it possible to remove it without disturbing the cold water feed?

Is it just a push fit onto the control block? I've remove all the fixing screws I can see but it still won't budge and am reluctant to apply too much force it until I am sure.

edit: should add that I've checked the flow, seems ok and descaled the shower head.
thanks

Bob

 

[seco services]

No you must isolate the cold feed to the shower before removing anything.
To get the heat can out you need to also remove the flow valve and switch assembly.

Heat can would be the very last result.

Have u cleaned the inlet filter ?
cleaned and tried without the head on ?
checked the hose isn't collapsing inside ?

 

[Bob2016]

Thanks for your advice.

I removed and cleaned the filter, there was a small amount crud around it, cleaned it and refitted.

Also removed the heater assembly, didn't descale as looking inside I didn't see any sign of scale build up. However the top of the heater where the terminals and safety cutoff switch is fitted had a fine layer of what looked like fine salt crystals (presumably limescale) which had also spread under the safety switch. Am concerned this might mean there is a leak around the terminals although it was bone dry maybe it only happens when hot? No other indications inside the unit of any water ingress.

Removed the safety switch and that also had a coating on its contact plate. Cleaned it off tested it was working ok with a meter, refitted everything. Ran the shower for several minutes and no sign of hot/cold cycling, just concerned as to whether I have a leak and for safety should just replace the whole thing.

regards

Bob