Replacing Mira shower cartridge hasn't solved temperature problem

[subzero]

We have a combi-fed Mira Excel shower, which has developed a temperature problem. Used to run hot, but now only runs a touch above luke warm.

Here are the symptoms-

Turning the temperature control on the shower fully to the left (hot) results in a brief moment of full hot water before then returning to a luke warm temperature. Noticeably, the throughput on that side of the temperature scale, is less than the cold pressure.

Having researched the problem, and consulted our plumber, the conclusion was that the shower cartridge was at fault. We ordered a new one (for a Kings Ransom) which was then fitted, but the problem has remained exactly the same.

Also, to rule out the shower head being the cause, we removed that and repeated the tests but the results were exactly the same.

Basin hot water is fine.

The boiler is less than two years old and regularly serviced.

Unless we are very unlucky to have received a faulty replacement cartridge, not sure how to progress this one. The fact that hot water *is* getting through very briefly, at certain points when turning the control on the shower, suggests that there is no problem with the actual hot water feed from the boiler to the shower valve.

Thanks in advance for any advice on this.

 

[picasso]

If you have access to the shower pipes see if the hot pipe runs hot then lukewarm, you might have another tap or shower passing cold water into the hot supply.

 

[DomBray]

Hello!

We have this exact same problem, how did you resolve it? Thanks