Lack of hot water from shower

[CharlieB1981]

I have a 1yr old Mira mixer shower and combo boiler.

All taps work fine and have hot water flowing as long as I only open them half way. Open them any more and it's tepid at best, but the shower barely gets warm at all, I may get a short burst of hot water for a second then goes Luke warm.

Any ideas on what the problem could be?

Thanks in advance

 

[Gas2Air]

I have a 1yr old Mira mixer shower and combo boiler.

All taps work fine and have hot water flowing as long as I only open them half way. Open them any more and it's tepid at best, but the shower barely gets warm at all, I may get a short burst of hot water for a second then goes Luke warm.

Any ideas on what the problem could be?

Thanks in advance

Search mixer passing. Common fault. "Combo" boiler does depend on flow rate and temp coming in from mains cold supply so reducing the flow at taps can help if no other faults are to blame.

 

[CharlieB1981]

Cheers, not sure if mixer passing is the problem, I've isolated the hot water, then turned them on full and no sign of cold water passing through. I've already got the flow restrictor that came with the shower in place but still have the problem