Shower temperature is too hot now combi boiler has been installed

[Connor Williams]

Hello, I am having problems with the temperature of my shower since I have had a new Combi boiler installed. The shower is a single lever mixer valve and I can no longer get the right temperature as the water gets too hot.
Should I install a gate valve and reduce the pressure of the hot so the cold water can help reduce the temperature or is a special shower cartridge required?
Any help would be greatly appreciated, many thanks.

All the best,
Connor

 

[Howsie]

Did you have a combi before?

 

[Jimbob]

Turn the boiler dhw temperature down? If you can't adjust the temperature, get the installer back to check the temperature at the taps

 

[secret squirrel]

It could be that you've got a manual mixer cartridge and not a thermostatic one.

The only way you'd know is by taking the cartridge out and having a look.

 

[Connor Williams]

Thanks for the help, the shower is not mixing the water at all, it is either very hot or completely cold. The Combi is a Worcester Greenstar 24i jr, there is no temperature gauge for the hot water and it should be fixed at 55 degrees but it seems a lot hotter.
Silly question but what is the difference I should notice in a manual and thermostatic cartridge?
I have unscrewed the spindle and the cartridge has a spring and short black rubber tip inside, is this thermostatic?
Many thanks for the help, greatly appreciated!

All the best,
Connor

 

[secret squirrel]

Depends on the make of shower, a thermostatic cartridge will mix the temp for you and (unless it is knackered) will do its best to regulate the temperature. These come in different guises, low pressure and high pressure.

A manual mixer is as it says you stand in the shower mixing the temperature to suit yourself.

Most showers with a manual mixer can be upgraded, I think that you either have a manual mixer OR a knackered cartridge OR an unsuitable cartridge for your boiler.

You now have a high pressure system. If you've gone from combi to combi, nothing much should have changed

IMO the first step I'd take is replacing the cartridge.