Worcester Greenstar 37CDi combi boiler sometimes gives cooler hot water

[screamer]

When using the hot water there's times when you turn the hot tap on and the hot water is noticeably cooler than normal.
Then you can use the hot water tap again 5 minutes later and it's back to normal.

Boiler is a Greenstar 37CDi

 

[screamer]

bump (for anyone who was out at the weekend, like myself!)

 

[Johntheo5]

That boiler should give 10.6LPM at 60C from cold mains at 10C.
Can you set the DHW temp to max and then open one or more hot taps to give say 8 to 10LPM and then measure or estimate the HW temperature.

 

[screamer]

hi John,

Thanks for your reply, i'll need to get a thermometer to try this.


Just for more info.
It's only my wife & I in the house, this temp difference can happen when no one else is using a tap.
Example, me doing the washing up and my wife sitting at the dining room table.