Water comes out of taps hot enough to burn, but the shower is only warm-ish.

[simbob]

Hi all,

Wondering if anyone can help out with this quandary. I recently put in a new shower (not significant but acts as benchmark) so i know how hot to turn the thermo to for a comfortable temperature. In the last couple of months i've had to move the thermo gradually from 9 o'clock to 6 o'clock (which is the limit) and it's only just about what i'd consider warm enough. Same thing has happened to the downstairs shower, so i reckon it's got to be the boiler. Water comes out of the taps hot enough to burn, but the showers seem to struggle. I've tried reducing the flow by half turning the tap but doesn't seem to make much difference, but if someone turns on a tap elsewhere at the same time it goes to cold followed by scalding hot temp, before settling back at warm-ish. I've had the thermo controls apart and turned up to their limit and still doesn't get really hot, although i must stress this has not always been the case and the central heating works fine.

The boiler is a Ferroli Optimax HE31c and only 3 years old and been serviced every year

Any thoughts/solutions?

 

[Gray0689]

Sounds like the water is to hot and wrecked the thermostatic cartridges in showers

 

[Gray0689]

Or too much pressure and boiler can't heat in time

 

[albabe]

The Ferroli Optimax HE31c is a condensing Combi Boiler, so it shouldn't be hot water pressure, (cold on mains high, hot from static head to cylinder low).
The other hot taps are delivering hot water "hot enough to burn".
The recomendations are for domestic hot water to be delivered at 60C max, above this deposits from the water will form quickly. The mixers could be "furring" up and not allowing the thermostatic controls to move freely.

 

[simbob]

The Ferroli Optimax HE31c is a condensing Combi Boiler, so it shouldn't be hot water pressure, (cold on mains high, hot from static head to cylinder low).
The other hot taps are delivering hot water "hot enough to burn".
The recomendations are for domestic hot water to be delivered at 60C max, above this deposits from the water will form quickly. The mixers could be "furring" up and not allowing the thermostatic controls to move freely.

Boiler max water temp is 55 degrees, so i can't believe it's causing damage, also the new shower has only been in two months

 

[lbp plg & htg]

Shower cartridge problem - simples!

 

[PlumbBobBob]

could it be something to do with the time of year and much colder mains water coming in?

 

[albabe]

Ok, turn it up a bit and slow the cold water down into the boiler. you can't lower the incoming pressure but you can change the water flow rate. The cold water going direct to the mixer is obviously also colder, so the task of giving you the showering temperature you want is getting harder.
The cold water temperature has dropped due to time of year and the boiler only has a certain capability of raising water temperature.
The mixers can't give you what isn't there.