Mira Excel Temperature not hot

[Starship001]

Hi All

We have an old Mira Excel Thermostatic Shower (pre-2003 - no lever) running off pumped hot and cold supply. All was fine until I upgraded the pump from 2.0 to 2.5 bar. Now it gets no warmer from position 3-7 on the dial. Can I reset the pressure on the existing cartridge, or do I need to switch to a higher pressure cartridge?

Thanks in advance

 

[ReJect]

Shower valve should still be fine with higher pressure.
On the Excel valve there are fine gauze filters on connections to cartridge. The hot blocks very easily and both filters need occasionally cleaned.
Water needs turned off and after the knob controls are removed there will be four bolts to remove the cartridge

 

[Starship001]

Thanks, much appreciated. I'll give that a try, but I suspect the cartridge is now past it's prime and long overdue for replacement.

 

[ReJect]

Thanks, much appreciated. I'll give that a try, but I suspect the cartridge is now past it's prime and long overdue for replacement.

The Mira Excel cartridge seem to be very reliable, so hopefully you won’t need to replace it as it is fairly costly.
The filters are a common problem to be blocked if not cleaned every few years.
I repaired same valve and after cleaning blocked filters the customer later told me the flow rates are greatly improved

 

[Starship001]

Yikes! You were right about the gauze filters - not cleaned in 20 years - so flow rate much improved. However still no temperature variation.

 

[ReJect]

Yikes! You were right about the gauze filters - not cleaned in 20 years - so flow rate much improved. However still no temperature variation.

If shower valve hadn’t been tampered with before it began to give trouble, then maybe the cartridge is faulty.
But I would check flow is getting to shower from both the hot and cold properly.
Make sure no valves are only part open (red handled gate valves are notorious for seizing) and no debris stuck anywhere in fittings and valves. Also make sure any valves (if there are any) on pump hoses are open.

 

[Starship001]

Nothing had been touched until the upgraded pump. There are no issues with flow, and I ensure all my valves are fully opened then given a half turn clockwise as this greatly reduces jamming. I understand from Mira the cartridge has an internal (wax?) part that can eventually fail, so I'm resigned to a replacement now. Thankfully the fixed temp is okay for a shower. . Your help much appreciated