Baxi 105e Hot water pressure problem??!

[henryfire]

Hi everyone, when i turn on hot water tap i get hot water once boiler fired up. Only problem is once it reaches temp the pressure seems to drop away? This is no problem in kitchen or for washing hands etc as i can just open tap further to increase flow but when i have a shower it starts off okay but when pressure drops i get lukewarm water! Any ideas appreciated

Henry

 

[jamesdean]

Hi everyone, when i turn on hot water tap i get hot water once boiler fired up. Henry

Boiler seems fine, have you checked the shower

 

[henryfire]

thanks for quick reply, shower was installed 10 months ago and was working fine. The only reason i think its the boiler is that when i run the utility hot tap for example, i get a steady flow of water which gradually gets warm to hot as you'd expect, but as soon as it gets hot the flow drops away so much so you have to open tap further to increase flow again and get hot water?

 

[henryfire]

you've now got me thinking, its a thermostatic mixer shower, what do i need to check to eliminate this??

 

[Agile]

As an engineer I can only work on facts!

Can you measure the hot water flow from your hot taps?

To help its measured in litres per minute!

Your boiler can only heat about 11 li/min by about 35°C.

Tony

 

[jamesdean]

you've now got me thinking, its a thermostatic mixer shower, what do i need to check to eliminate this??

might be a scaled up heat exchanger , how old is the boiler?

 

[swbjackson]

thanks for quick reply, shower was installed 10 months ago and was working fine. The only reason i think its the boiler is that when i run the utility hot tap for example, i get a steady flow of water which gradually gets warm to hot as you'd expect, but as soon as it gets hot the flow drops away so much so you have to open tap further to increase flow again and get hot water?

That's quite common. I've found that quite a lot, don't know if it's the washer expanding or the tap mechanism. As the flow increases when you open the tap further it's highly unlikely that the heat exchanger is scaled.

Mike

 

[jamesdean]

As the flow increases when you open the tap further it's highly unlikely that the heat exchanger is scaled.

Shower then.

 

[2face]

i have come across a few 105 with exchanges scaled up but i dont think its that in your case.

if all the taps are ok and its just the shower , maybe the model of the shower would help us ??

i have had this problem with the older miras and a new cartridge has fixed it.

 

[henryfire]

thanks for all your quick replies, i didn't have time to check anything today and am work currently, shower is a grohe thermostatic i think the model is a grohetherm 1000. Like i said, no problems prior to this and shower only ten months old!