This question is regarding Mira Excel/Select Thermostatic Cartridge - 903.33

Mira Excel Thermostatic Mixer

When the shower is turned on the water is cool but gradually heats up to hot and cuts out - does the cartridge need changing?
Asked 11 years ago by Anonymous

Regarding the temperaturefluctuation or cool running it could be a faulty cartridge however to checkthis, see if you can get hold of the hot supply pipe before it enters theshower or perhaps as it leaves the boiler.

 

If when holding this pipe thetemperature fluctuates or goes cool then the problem is not with the shower butmore likely with the boiler as the shower can only deliver what the boilersends to it.

Disregard the temperature at thetaps as they have a different flow rate.

 

If the flow to the shower is OK it's best just to replacethe cartridge, however it is probably worth stripping the cartridge out andchecking that the inlet filters are clean, before buying a new cartridge.

 Turnoff hot and cold water supply

 

Pull front temperature knob off The rest of the knob assy.just unclips

 

Remove 4 screws that hold cartridge into body

 

Pull old cartridge forward shouldn't be too tight

 

Set new cartridge for High/Low pressure (instructionswith cartridge)

 

Slip new cartridge into place remember to check that the newseals are all in place (and don't drop out as you push back)

 

Tighten screws be careful not to over tighten

 

Refit knobs.

 

Turn on water and test. (Occasionally you will have to resetthe cartridge temperature, instructions with cartridge)

 

Easy peasy!!!!

 

 

Cartridge   Mira 903.33 This cartridge supersedes the previous high and low pressure versions

 

Click on the link below, choose the manufacturer of the showeryou have, scroll down the list of parts and select the part number you require.

 

You can then purchase the items online or call the office on0131 443 9917 pressing option # 1 for spares.

 

http://www.shower-warehouse.co.uk/erol.html#588X0

Answered 11 years ago by The Shower Doctor

You may want to check you have balanced pressures & flow rates to shower.



If you have a combi boiler, there is only so much water they can heat in-line which will affect your flow rate on hot side.



Your cold water flow rate could be 'blowing-out' the hot. Even with balanced pressures, your flow rates can still be dramatically different.



You will need a flow-cup to measure your flow rates

Answered 11 years ago by Anonymous

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