Help - shower is hot or cold but not nice

[lfnfan]

I need some help to diagnose and fix a problem shower.

The problem: there used to be a gentle progression between freezing and scalding, with plenty of scope for finding the right temperature. Now, however, it's either scalding or freezing, with only one precise tap position yielding a bearable temp.

Please can you let me know what info you need to diagnose what's gone wrong? I can find out the boiler specs (I know it's a 2-year-old combi), and may be able to get hold of flow stats also. The shower runs from the DHW, and the shower mixer tap is a horizontal bar that has a tap on the left that regulates pressure, and a tap on the right that regulates temperature and a plunger in the middle to send water to the bath or the shower head.

Any help much appreciated!

 

[lfnfan]

well, it's an Ideal Excel HE C24, 2006 model

using the bucket test I got 15l/min flow

Thanks in advance

 

[g20]

Hows the hot water on other taps in the house? (are they a nice steady temp?) If so it's your shower mixer thats at fault not the boiler.

 

[lfnfan]

Other taps stay about the same temperature.

For the hot taps, the flow level starts off "as set" by the turn of the tap, but goes progressively weaker after 20 - 30 seconds as the water heats up. Then the hot tap has to be opened further to get back to the flow required. This has always been the case, even when the shower was behaving itself.

Many thanks

 

[g20]

Can you remember the make and model of shower, the cartridge probably needs replacing

 

[lfnfan]

Thanks. I will have a look for some distinguishing marks on the fitting.

It's about 2 years old, and probably an el-cheapo job (rented flat). It's a bath/shower mixer tap, horizontal bar style, that has a tap on the left end that regulates flow, and a tap (edit: cartridge) on the right end to set temperature, and a plunger in the middle to send water to the bath or the shower head.

Could living in a hard water area also be a factor?

Thanks again

 

[lfnfan]

no distinguising make / model marks, but I took a few pics which may help.

//www.diynot.com/network/lfnfan/albums/3410

thanks