Thermostatic Mixer Shower Valve with pumped hot water only

[helenpenny]

Good idea! I have a few things to try so will see if anything works. Thanks!

 

[metalfury]

I have just bumped this old post as I have a similar problem and this post seems to be the closest!

Here's my scenario!

I have a Mixer Shower (Triton dual control), Combi Boiler (Worcester 24CDI) and live in a very hard water area (West Reading).

After about 7:30AM, if I take a shower the boiler will not kick in and provide hot water unless the hot tap in the sink is slightly on. If I have a shower very early in the morning this is rarely a problem. Later in the day I am often unable to have a hot shower unless the hot tap is on nearly full - the result of which is a trickle from the shower and a frustrated me!

It seems like it needs the additional flow coming out from the hot tap before the boiler will 'notice' that it needs to start heating the water.

I'm assuming that there is a loss in mains pressure due to everyone in the street having a shower which is built up overnight? However, pressure from the shower still feels reasonable so I guess this isn't the main issue, just something that contributes to it?

From looking around the net and forums the issue maybe one of the following:

• The Flow Regulator in the boiler
  The Mixer Valve in the shower
  The Thermostatic Cartridge in the shower
  Some sort of blockage
  Some sort adjustment required with the shower

If it is relevant - The shower was fitted probably 4 years ago (guess) and the boiler is serviced/repaired due to issues caused by the hard water around once every 18 months.

I'm not a plumber but a competent DIYer. Any advice would be appreciated so I would know whether to tackle it myself, call my Boiler Engineer or get the plumber in.

Many thanks in advance.

metalfury